diff --git a/assignment-client/src/audio/AudioMixer.cpp b/assignment-client/src/audio/AudioMixer.cpp
index bb03a6ec93..ab4b20b9cc 100644
--- a/assignment-client/src/audio/AudioMixer.cpp
+++ b/assignment-client/src/audio/AudioMixer.cpp
@@ -55,7 +55,8 @@ QVector<AudioMixer::ZoneSettings> AudioMixer::_zoneSettings;
 QVector<AudioMixer::ReverbSettings> AudioMixer::_zoneReverbSettings;
 
 AudioMixer::AudioMixer(ReceivedMessage& message) :
-    ThreadedAssignment(message) {
+    ThreadedAssignment(message)
+{
 
     // Always clear settings first
     // This prevents previous assignment settings from sticking around
@@ -92,7 +93,21 @@ AudioMixer::AudioMixer(ReceivedMessage& message) :
     packetReceiver.registerListener(PacketType::NodeMuteRequest, this, "handleNodeMuteRequestPacket");
     packetReceiver.registerListener(PacketType::KillAvatar, this, "handleKillAvatarPacket");
 
+    packetReceiver.registerListenerForTypes({
+        PacketType::ReplicatedMicrophoneAudioNoEcho,
+        PacketType::ReplicatedMicrophoneAudioWithEcho,
+        PacketType::ReplicatedInjectAudio,
+        PacketType::ReplicatedSilentAudioFrame
+    },
+        this, "queueReplicatedAudioPacket"
+    );
+
     connect(nodeList.data(), &NodeList::nodeKilled, this, &AudioMixer::handleNodeKilled);
+    connect(nodeList.data(), &NodeList::nodeAdded, this, [this](const SharedNodePointer& node) {
+        if (node->getType() == NodeType::DownstreamAudioMixer) {
+            node->activatePublicSocket();
+        }
+    });
 }
 
 void AudioMixer::queueAudioPacket(QSharedPointer<ReceivedMessage> message, SharedNodePointer node) {
@@ -103,6 +118,33 @@ void AudioMixer::queueAudioPacket(QSharedPointer<ReceivedMessage> message, Share
     getOrCreateClientData(node.data())->queuePacket(message, node);
 }
 
+void AudioMixer::queueReplicatedAudioPacket(QSharedPointer<ReceivedMessage> message) {
+    // make sure we have a replicated node for the original sender of the packet
+    auto nodeList = DependencyManager::get<NodeList>();
+
+    QUuid nodeID =  QUuid::fromRfc4122(message->readWithoutCopy(NUM_BYTES_RFC4122_UUID));
+
+    auto replicatedNode = nodeList->addOrUpdateNode(nodeID, NodeType::Agent,
+                                                    message->getSenderSockAddr(), message->getSenderSockAddr(),
+                                                    true, true);
+    replicatedNode->setLastHeardMicrostamp(usecTimestampNow());
+
+    // construct a "fake" audio received message from the byte array and packet list information
+    auto audioData = message->getMessage().mid(NUM_BYTES_RFC4122_UUID);
+
+    PacketType rewrittenType = REPLICATED_PACKET_MAPPING.key(message->getType());
+
+    if (rewrittenType == PacketType::Unknown) {
+        qDebug() << "Cannot unwrap replicated packet type not present in REPLICATED_PACKET_WRAPPING";
+    }
+
+    auto replicatedMessage = QSharedPointer<ReceivedMessage>::create(audioData, rewrittenType,
+                                                                     versionForPacketType(rewrittenType),
+                                                                     message->getSenderSockAddr(), nodeID);
+
+    getOrCreateClientData(replicatedNode.data())->queuePacket(replicatedMessage, replicatedNode);
+}
+
 void AudioMixer::handleMuteEnvironmentPacket(QSharedPointer<ReceivedMessage> message, SharedNodePointer sendingNode) {
     auto nodeList = DependencyManager::get<NodeList>();
 
@@ -347,7 +389,7 @@ void AudioMixer::start() {
     auto nodeList = DependencyManager::get<NodeList>();
 
     // prepare the NodeList
-    nodeList->addSetOfNodeTypesToNodeInterestSet({ NodeType::Agent, NodeType::EntityScriptServer });
+    nodeList->addSetOfNodeTypesToNodeInterestSet({ NodeType::Agent, NodeType::DownstreamAudioMixer, NodeType::EntityScriptServer });
     nodeList->linkedDataCreateCallback = [&](Node* node) { getOrCreateClientData(node); };
 
     // parse out any AudioMixer settings
@@ -506,7 +548,7 @@ void AudioMixer::clearDomainSettings() {
     _zoneReverbSettings.clear();
 }
 
-void AudioMixer::parseSettingsObject(const QJsonObject &settingsObject) {
+void AudioMixer::parseSettingsObject(const QJsonObject& settingsObject) {
     qDebug() << "AVX2 Support:" << (cpuSupportsAVX2() ? "enabled" : "disabled");
 
     if (settingsObject.contains(AUDIO_THREADING_GROUP_KEY)) {
diff --git a/assignment-client/src/audio/AudioMixer.h b/assignment-client/src/audio/AudioMixer.h
index 18e754016e..e542d82a6a 100644
--- a/assignment-client/src/audio/AudioMixer.h
+++ b/assignment-client/src/audio/AudioMixer.h
@@ -63,6 +63,7 @@ private slots:
     void handleKillAvatarPacket(QSharedPointer<ReceivedMessage> packet, SharedNodePointer sendingNode);
 
     void queueAudioPacket(QSharedPointer<ReceivedMessage> packet, SharedNodePointer sendingNode);
+    void queueReplicatedAudioPacket(QSharedPointer<ReceivedMessage> packet);
     void removeHRTFsForFinishedInjector(const QUuid& streamID);
     void start();
 
diff --git a/assignment-client/src/audio/AudioMixerClientData.cpp b/assignment-client/src/audio/AudioMixerClientData.cpp
index d5e06504a6..bf19a02d9a 100644
--- a/assignment-client/src/audio/AudioMixerClientData.cpp
+++ b/assignment-client/src/audio/AudioMixerClientData.cpp
@@ -68,9 +68,21 @@ void AudioMixerClientData::processPackets() {
             case PacketType::MicrophoneAudioWithEcho:
             case PacketType::InjectAudio:
             case PacketType::AudioStreamStats:
-            case PacketType::SilentAudioFrame: {
+            case PacketType::SilentAudioFrame:
+            case PacketType::ReplicatedMicrophoneAudioNoEcho:
+            case PacketType::ReplicatedMicrophoneAudioWithEcho:
+            case PacketType::ReplicatedInjectAudio:
+            case PacketType::ReplicatedSilentAudioFrame: {
+
+                if (node->isUpstream() && !_hasSetupCodecForUpstreamNode) {
+                    setupCodecForReplicatedAgent(packet);
+                }
+
                 QMutexLocker lock(&getMutex());
                 parseData(*packet);
+                
+                optionallyReplicatePacket(*packet, *node);
+
                 break;
             }
             case PacketType::NegotiateAudioFormat:
@@ -97,6 +109,59 @@ void AudioMixerClientData::processPackets() {
     assert(_packetQueue.empty());
 }
 
+bool isReplicatedPacket(PacketType packetType) {
+    return packetType == PacketType::ReplicatedMicrophoneAudioNoEcho
+        || packetType == PacketType::ReplicatedMicrophoneAudioWithEcho
+        || packetType == PacketType::ReplicatedInjectAudio
+        || packetType == PacketType::ReplicatedSilentAudioFrame;
+}
+
+void AudioMixerClientData::optionallyReplicatePacket(ReceivedMessage& message, const Node& node) {
+
+    // first, make sure that this is a packet from a node we are supposed to replicate
+    if (node.isReplicated()) {
+
+        // now make sure it's a packet type that we want to replicate
+
+        // first check if it is an original type that we should replicate
+        PacketType mirroredType = REPLICATED_PACKET_MAPPING.value(message.getType());
+
+        if (mirroredType == PacketType::Unknown) {
+            // if it wasn't check if it is a replicated type that we should re-replicate
+            if (REPLICATED_PACKET_MAPPING.key(message.getType()) != PacketType::Unknown) {
+                mirroredType = message.getType();
+            } else {
+                qDebug() << "Packet passed to optionallyReplicatePacket was not a replicatable type - returning";
+                return;
+            }
+        }
+
+        std::unique_ptr<NLPacket> packet;
+        auto nodeList = DependencyManager::get<NodeList>();
+
+        // enumerate the downstream audio mixers and send them the replicated version of this packet
+        nodeList->unsafeEachNode([&](const SharedNodePointer& downstreamNode) {
+            if (downstreamNode->getType() == NodeType::DownstreamAudioMixer) {
+                // construct the packet only once, if we have any downstream audio mixers to send to
+                if (!packet) {
+                    // construct an NLPacket to send to the replicant that has the contents of the received packet
+                    packet = NLPacket::create(mirroredType);
+
+                    if (!isReplicatedPacket(message.getType())) {
+                        // since this packet will be non-sourced, we add the replicated node's ID here
+                        packet->write(node.getUUID().toRfc4122());
+                    }
+
+                    packet->write(message.getMessage());
+                }
+                
+                nodeList->sendUnreliablePacket(*packet, *downstreamNode);
+            }
+        });
+    }
+
+}
+
 void AudioMixerClientData::negotiateAudioFormat(ReceivedMessage& message, const SharedNodePointer& node) {
     quint8 numberOfCodecs;
     message.readPrimitive(&numberOfCodecs);
@@ -188,8 +253,11 @@ int AudioMixerClientData::parseData(ReceivedMessage& message) {
         bool isMicStream = false;
 
         if (packetType == PacketType::MicrophoneAudioWithEcho
+            || packetType == PacketType::ReplicatedMicrophoneAudioWithEcho
             || packetType == PacketType::MicrophoneAudioNoEcho
-            || packetType == PacketType::SilentAudioFrame) {
+            || packetType == PacketType::ReplicatedMicrophoneAudioNoEcho
+            || packetType == PacketType::SilentAudioFrame
+            || packetType == PacketType::ReplicatedSilentAudioFrame) {
 
             QWriteLocker writeLocker { &_streamsLock };
 
@@ -209,7 +277,8 @@ int AudioMixerClientData::parseData(ReceivedMessage& message) {
                 avatarAudioStream->setupCodec(_codec, _selectedCodecName, AudioConstants::MONO);
                 qDebug() << "creating new AvatarAudioStream... codec:" << _selectedCodecName;
 
-                connect(avatarAudioStream, &InboundAudioStream::mismatchedAudioCodec, this, &AudioMixerClientData::handleMismatchAudioFormat);
+                connect(avatarAudioStream, &InboundAudioStream::mismatchedAudioCodec,
+                        this, &AudioMixerClientData::handleMismatchAudioFormat);
 
                 auto emplaced = _audioStreams.emplace(
                     QUuid(),
@@ -224,10 +293,12 @@ int AudioMixerClientData::parseData(ReceivedMessage& message) {
             writeLocker.unlock();
 
             isMicStream = true;
-        } else if (packetType == PacketType::InjectAudio) {
+        } else if (packetType == PacketType::InjectAudio
+                   || packetType == PacketType::ReplicatedInjectAudio) {
             // this is injected audio
             // grab the stream identifier for this injected audio
             message.seek(sizeof(quint16));
+
             QUuid streamIdentifier = QUuid::fromRfc4122(message.readWithoutCopy(NUM_BYTES_RFC4122_UUID));
 
             bool isStereo;
@@ -608,3 +679,22 @@ bool AudioMixerClientData::shouldIgnore(const SharedNodePointer self, const Shar
 
     return shouldIgnore;
 }
+
+void AudioMixerClientData::setupCodecForReplicatedAgent(QSharedPointer<ReceivedMessage> message) {
+    // hop past the sequence number that leads the packet
+    message->seek(sizeof(quint16));
+
+    // pull the codec string from the packet
+    auto codecString = message->readString();
+
+    qDebug() << "Manually setting codec for replicated agent" << uuidStringWithoutCurlyBraces(getNodeID())
+        << "-" << codecString;
+
+    const std::pair<QString, CodecPluginPointer> codec = AudioMixer::negotiateCodec({ codecString });
+    setupCodec(codec.second, codec.first);
+
+    _hasSetupCodecForUpstreamNode = true;
+
+    // seek back to the beginning of the message so other readers are in the right place
+    message->seek(0);
+}
diff --git a/assignment-client/src/audio/AudioMixerClientData.h b/assignment-client/src/audio/AudioMixerClientData.h
index 8d76cda2f1..76a9cd6aa7 100644
--- a/assignment-client/src/audio/AudioMixerClientData.h
+++ b/assignment-client/src/audio/AudioMixerClientData.h
@@ -26,7 +26,6 @@
 #include "PositionalAudioStream.h"
 #include "AvatarAudioStream.h"
 
-
 class AudioMixerClientData : public NodeData {
     Q_OBJECT
 public:
@@ -108,6 +107,8 @@ public:
     bool getRequestsDomainListData() { return _requestsDomainListData; }
     void setRequestsDomainListData(bool requesting) { _requestsDomainListData = requesting; }
 
+    void setupCodecForReplicatedAgent(QSharedPointer<ReceivedMessage> message);
+
 signals:
     void injectorStreamFinished(const QUuid& streamIdentifier);
 
@@ -124,6 +125,8 @@ private:
     QReadWriteLock _streamsLock;
     AudioStreamMap _audioStreams; // microphone stream from avatar is stored under key of null UUID
 
+    void optionallyReplicatePacket(ReceivedMessage& packet, const Node& node);
+
     using IgnoreZone = AABox;
     class IgnoreZoneMemo {
     public:
@@ -181,6 +184,8 @@ private:
 
     bool _shouldMuteClient { false };
     bool _requestsDomainListData { false };
+
+    bool _hasSetupCodecForUpstreamNode { false };
 };
 
 #endif // hifi_AudioMixerClientData_h
diff --git a/assignment-client/src/audio/AudioMixerSlave.cpp b/assignment-client/src/audio/AudioMixerSlave.cpp
index d01d961e33..2d800c3561 100644
--- a/assignment-client/src/audio/AudioMixerSlave.cpp
+++ b/assignment-client/src/audio/AudioMixerSlave.cpp
@@ -74,6 +74,10 @@ void AudioMixerSlave::mix(const SharedNodePointer& node) {
         return;
     }
 
+    if (node->isUpstream()) {
+        return;
+    }
+
     // check that the stream is valid
     auto avatarStream = data->getAvatarAudioStream();
     if (avatarStream == nullptr) {
diff --git a/assignment-client/src/avatars/AvatarMixer.cpp b/assignment-client/src/avatars/AvatarMixer.cpp
index c8b68a740c..f1e30f4442 100644
--- a/assignment-client/src/avatars/AvatarMixer.cpp
+++ b/assignment-client/src/avatars/AvatarMixer.cpp
@@ -54,8 +54,108 @@ AvatarMixer::AvatarMixer(ReceivedMessage& message) :
     packetReceiver.registerListener(PacketType::RadiusIgnoreRequest, this, "handleRadiusIgnoreRequestPacket");
     packetReceiver.registerListener(PacketType::RequestsDomainListData, this, "handleRequestsDomainListDataPacket");
 
+    packetReceiver.registerListenerForTypes({
+        PacketType::ReplicatedAvatarIdentity,
+        PacketType::ReplicatedKillAvatar
+    }, this, "handleReplicatedPacket");
+
+    packetReceiver.registerListener(PacketType::ReplicatedBulkAvatarData, this, "handleReplicatedBulkAvatarPacket");
+
     auto nodeList = DependencyManager::get<NodeList>();
     connect(nodeList.data(), &NodeList::packetVersionMismatch, this, &AvatarMixer::handlePacketVersionMismatch);
+    connect(nodeList.data(), &NodeList::nodeAdded, this, [this](const SharedNodePointer& node) {
+        if (node->getType() == NodeType::DownstreamAvatarMixer) {
+            getOrCreateClientData(node);
+            node->activatePublicSocket();
+        }
+    });
+}
+
+SharedNodePointer addOrUpdateReplicatedNode(const QUuid& nodeID, const HifiSockAddr& senderSockAddr) {
+    auto replicatedNode = DependencyManager::get<NodeList>()->addOrUpdateNode(nodeID, NodeType::Agent,
+                                                                              senderSockAddr,
+                                                                              senderSockAddr,
+                                                                              true, true);
+
+    replicatedNode->setLastHeardMicrostamp(usecTimestampNow());
+
+    return replicatedNode;
+}
+
+void AvatarMixer::handleReplicatedPacket(QSharedPointer<ReceivedMessage> message) {
+    auto nodeList = DependencyManager::get<NodeList>();
+    auto nodeID = QUuid::fromRfc4122(message->peek(NUM_BYTES_RFC4122_UUID));
+
+    auto replicatedNode = addOrUpdateReplicatedNode(nodeID, message->getSenderSockAddr());
+
+    if (message->getType() == PacketType::ReplicatedAvatarIdentity) {
+        handleAvatarIdentityPacket(message, replicatedNode);
+    } else if (message->getType() == PacketType::ReplicatedKillAvatar) {
+        handleKillAvatarPacket(message, replicatedNode);
+    }
+}
+
+void AvatarMixer::handleReplicatedBulkAvatarPacket(QSharedPointer<ReceivedMessage> message) {
+    while (message->getBytesLeftToRead()) {
+        // first, grab the node ID for this replicated avatar
+        auto nodeID = QUuid::fromRfc4122(message->readWithoutCopy(NUM_BYTES_RFC4122_UUID));
+
+        // make sure we have an upstream replicated node that matches
+        auto replicatedNode = addOrUpdateReplicatedNode(nodeID, message->getSenderSockAddr());
+
+        // grab the size of the avatar byte array so we know how much to read
+        quint16 avatarByteArraySize;
+        message->readPrimitive(&avatarByteArraySize);
+
+        // read the avatar byte array
+        auto avatarByteArray = message->read(avatarByteArraySize);
+
+        // construct a "fake" avatar data received message from the byte array and packet list information
+        auto replicatedMessage = QSharedPointer<ReceivedMessage>::create(avatarByteArray, PacketType::AvatarData,
+                                                                         versionForPacketType(PacketType::AvatarData),
+                                                                         message->getSenderSockAddr(), nodeID);
+
+        // queue up the replicated avatar data with the client data for the replicated node
+        auto start = usecTimestampNow();
+        getOrCreateClientData(replicatedNode)->queuePacket(replicatedMessage, replicatedNode);
+        auto end = usecTimestampNow();
+        _queueIncomingPacketElapsedTime += (end - start);
+    }
+}
+
+void AvatarMixer::optionallyReplicatePacket(ReceivedMessage& message, const Node& node) {
+    // first, make sure that this is a packet from a node we are supposed to replicate
+    if (node.isReplicated()) {
+
+        // check if this is a packet type we replicate
+        // which means it must be a packet type present in REPLICATED_PACKET_MAPPING or must be the
+        // replicated version of one of those packet types
+        PacketType replicatedType = REPLICATED_PACKET_MAPPING.value(message.getType());
+
+        if (replicatedType == PacketType::Unknown) {
+            if (REPLICATED_PACKET_MAPPING.key(message.getType()) != PacketType::Unknown) {
+                replicatedType = message.getType();
+            } else {
+                qDebug() << __FUNCTION__ << "called without replicatable packet type - returning";
+                return;
+            }
+        }
+
+        std::unique_ptr<NLPacket> packet;
+
+        auto nodeList = DependencyManager::get<NodeList>();
+        nodeList->eachMatchingNode([&](const SharedNodePointer& node) {
+            return node->getType() == NodeType::DownstreamAvatarMixer;
+        }, [&](const SharedNodePointer& node) {
+            if (!packet) {
+                // construct an NLPacket to send to the replicant that has the contents of the received packet
+                packet = NLPacket::create(replicatedType, message.getSize());
+                packet->write(message.getMessage());
+            }
+
+            nodeList->sendUnreliablePacket(*packet, *node);
+        });
+    }
 }
 
 void AvatarMixer::queueIncomingPacket(QSharedPointer<ReceivedMessage> message, SharedNodePointer node) {
@@ -70,12 +170,14 @@ AvatarMixer::~AvatarMixer() {
 }
 
 void AvatarMixer::sendIdentityPacket(AvatarMixerClientData* nodeData, const SharedNodePointer& destinationNode) {
-    QByteArray individualData = nodeData->getAvatar().identityByteArray();
-    individualData.replace(0, NUM_BYTES_RFC4122_UUID, nodeData->getNodeID().toRfc4122());
-    auto identityPackets = NLPacketList::create(PacketType::AvatarIdentity, QByteArray(), true, true);
-    identityPackets->write(individualData);
-    DependencyManager::get<NodeList>()->sendPacketList(std::move(identityPackets), *destinationNode);
-    ++_sumIdentityPackets;
+    if (destinationNode->getType() == NodeType::Agent && !destinationNode->isUpstream()) {
+        QByteArray individualData = nodeData->getAvatar().identityByteArray();
+        individualData.replace(0, NUM_BYTES_RFC4122_UUID, nodeData->getNodeID().toRfc4122());
+        auto identityPackets = NLPacketList::create(PacketType::AvatarIdentity, QByteArray(), true, true);
+        identityPackets->write(individualData);
+        DependencyManager::get<NodeList>()->sendPacketList(std::move(identityPackets), *destinationNode);
+        ++_sumIdentityPackets;
+    }
 }
 
 std::chrono::microseconds AvatarMixer::timeFrame(p_high_resolution_clock::time_point& timestamp) {
@@ -132,7 +234,10 @@ void AvatarMixer::start() {
             auto start = usecTimestampNow();
             nodeList->nestedEach([&](NodeList::const_iterator cbegin, NodeList::const_iterator cend) {
                 std::for_each(cbegin, cend, [&](const SharedNodePointer& node) {
-                    manageIdentityData(node);
+                    if (node->getType() == NodeType::Agent && !node->isUpstream()) {
+                        manageIdentityData(node);
+                    }
+
                     ++_sumListeners;
                 });
             }, &lockWait, &nodeTransform, &functor);
@@ -310,13 +415,38 @@ void AvatarMixer::nodeKilled(SharedNodePointer killedNode) {
            }
         }
 
+        std::unique_ptr<NLPacket> killPacket;
+        std::unique_ptr<NLPacket> replicatedKillPacket;
+
         // this was an avatar we were sending to other people
         // send a kill packet for it to our other nodes
-        auto killPacket = NLPacket::create(PacketType::KillAvatar, NUM_BYTES_RFC4122_UUID + sizeof(KillAvatarReason));
-        killPacket->write(killedNode->getUUID().toRfc4122());
-        killPacket->writePrimitive(KillAvatarReason::AvatarDisconnected);
+        nodeList->eachMatchingNode([&](const SharedNodePointer& node) {
+            // we relay avatar kill packets to agents that are not upstream
+            // and downstream avatar mixers, if the node that was just killed was being replicated
+            return (node->getType() == NodeType::Agent && !node->isUpstream())
+                || (killedNode->isReplicated() && node->getType() == NodeType::DownstreamAvatarMixer);
+        }, [&](const SharedNodePointer& node) {
+            if (node->getType() == NodeType::Agent) {
+                if (!killPacket) {
+                    killPacket = NLPacket::create(PacketType::KillAvatar, NUM_BYTES_RFC4122_UUID + sizeof(KillAvatarReason));
+                    killPacket->write(killedNode->getUUID().toRfc4122());
+                    killPacket->writePrimitive(KillAvatarReason::AvatarDisconnected);
+                }
+
+                nodeList->sendUnreliablePacket(*killPacket, *node);
+            } else {
+                // send a replicated kill packet to the downstream avatar mixer
+                if (!replicatedKillPacket) {
+                    replicatedKillPacket = NLPacket::create(PacketType::ReplicatedKillAvatar,
+                                                  NUM_BYTES_RFC4122_UUID + sizeof(KillAvatarReason));
+                    replicatedKillPacket->write(killedNode->getUUID().toRfc4122());
+                    replicatedKillPacket->writePrimitive(KillAvatarReason::AvatarDisconnected);
+                }
+
+                nodeList->sendUnreliablePacket(*replicatedKillPacket, *node);
+            }
+        });
 
-        nodeList->broadcastToNodes(std::move(killPacket), NodeSet() << NodeType::Agent);
 
         // we also want to remove sequence number data for this avatar on our other avatars
         // so invoke the appropriate method on the AvatarMixerClientData for other avatars
@@ -429,12 +559,11 @@ void AvatarMixer::handleAvatarIdentityPacket(QSharedPointer<ReceivedMessage> mes
             AvatarData& avatar = nodeData->getAvatar();
 
             // parse the identity packet and update the change timestamp if appropriate
-            AvatarData::Identity identity;
-            AvatarData::parseAvatarIdentityPacket(message->getMessage(), identity);
             bool identityChanged = false;
             bool displayNameChanged = false;
             bool skeletonModelUrlChanged = false;
-            avatar.processAvatarIdentity(identity, identityChanged, displayNameChanged, skeletonModelUrlChanged);
+            avatar.processAvatarIdentity(message->getMessage(), identityChanged, displayNameChanged, skeletonModelUrlChanged);
+
             if (identityChanged) {
                 QMutexLocker nodeDataLocker(&nodeData->getMutex());
                 nodeData->flagIdentityChange();
@@ -451,11 +580,13 @@ void AvatarMixer::handleAvatarIdentityPacket(QSharedPointer<ReceivedMessage> mes
     _handleAvatarIdentityPacketElapsedTime += (end - start);
 }
 
-void AvatarMixer::handleKillAvatarPacket(QSharedPointer<ReceivedMessage> message) {
+void AvatarMixer::handleKillAvatarPacket(QSharedPointer<ReceivedMessage> message, SharedNodePointer node) {
     auto start = usecTimestampNow();
     DependencyManager::get<NodeList>()->processKillNode(*message);
     auto end = usecTimestampNow();
     _handleKillAvatarPacketElapsedTime += (end - start);
+
+    optionallyReplicatePacket(*message, *node);
 }
 
 void AvatarMixer::handleNodeIgnoreRequestPacket(QSharedPointer<ReceivedMessage> message, SharedNodePointer senderNode) {
@@ -707,7 +838,6 @@ void AvatarMixer::run() {
     connect(&domainHandler, &DomainHandler::settingsReceiveFail, this, &AvatarMixer::domainSettingsRequestFailed);
 
     ThreadedAssignment::commonInit(AVATAR_MIXER_LOGGING_NAME, NodeType::AvatarMixer);
-
 }
 
 AvatarMixerClientData* AvatarMixer::getOrCreateClientData(SharedNodePointer node) {
@@ -726,7 +856,7 @@ AvatarMixerClientData* AvatarMixer::getOrCreateClientData(SharedNodePointer node
 
 void AvatarMixer::domainSettingsRequestComplete() {
     auto nodeList = DependencyManager::get<NodeList>();
-    nodeList->addSetOfNodeTypesToNodeInterestSet({ NodeType::Agent, NodeType::EntityScriptServer });
+    nodeList->addSetOfNodeTypesToNodeInterestSet({ NodeType::Agent, NodeType::DownstreamAvatarMixer, NodeType::EntityScriptServer });
 
     // parse the settings to pull out the values we need
     parseDomainServerSettings(nodeList->getDomainHandler().getSettingsObject());
@@ -803,12 +933,13 @@ void AvatarMixer::parseDomainServerSettings(const QJsonObject& domainSettings) {
     static const QString AVATAR_WHITELIST_OPTION = "avatar_whitelist";
     _avatarWhitelist = domainSettings[AVATARS_SETTINGS_KEY].toObject()[AVATAR_WHITELIST_OPTION].toString(AVATAR_WHITELIST_DEFAULT).split(',', QString::KeepEmptyParts);
 
-     static const QString REPLACEMENT_AVATAR_OPTION = "replacement_avatar";
+    static const QString REPLACEMENT_AVATAR_OPTION = "replacement_avatar";
     _replacementAvatar = domainSettings[AVATARS_SETTINGS_KEY].toObject()[REPLACEMENT_AVATAR_OPTION].toString(REPLACEMENT_AVATAR_DEFAULT);
 
     if ((_avatarWhitelist.count() == 1) && _avatarWhitelist[0].isEmpty()) {
         _avatarWhitelist.clear(); // KeepEmptyParts above will parse "," as ["", ""] (which is ok), but "" as [""] (which is not ok).
     }
+
     if (_avatarWhitelist.isEmpty()) {
         qCDebug(avatars) << "All avatars are allowed.";
     } else {
diff --git a/assignment-client/src/avatars/AvatarMixer.h b/assignment-client/src/avatars/AvatarMixer.h
index f8ebe419a9..58d4487652 100644
--- a/assignment-client/src/avatars/AvatarMixer.h
+++ b/assignment-client/src/avatars/AvatarMixer.h
@@ -42,10 +42,12 @@ private slots:
     void handleAdjustAvatarSorting(QSharedPointer<ReceivedMessage> message, SharedNodePointer senderNode);
     void handleViewFrustumPacket(QSharedPointer<ReceivedMessage> message, SharedNodePointer senderNode);
     void handleAvatarIdentityPacket(QSharedPointer<ReceivedMessage> message, SharedNodePointer senderNode);
-    void handleKillAvatarPacket(QSharedPointer<ReceivedMessage> message);
+    void handleKillAvatarPacket(QSharedPointer<ReceivedMessage> message, SharedNodePointer senderNode);
     void handleNodeIgnoreRequestPacket(QSharedPointer<ReceivedMessage> message, SharedNodePointer senderNode);
     void handleRadiusIgnoreRequestPacket(QSharedPointer<ReceivedMessage> packet, SharedNodePointer sendingNode);
     void handleRequestsDomainListDataPacket(QSharedPointer<ReceivedMessage> message, SharedNodePointer senderNode);
+    void handleReplicatedPacket(QSharedPointer<ReceivedMessage> message);
+    void handleReplicatedBulkAvatarPacket(QSharedPointer<ReceivedMessage> message);
     void domainSettingsRequestComplete();
     void handlePacketVersionMismatch(PacketType type, const HifiSockAddr& senderSockAddr, const QUuid& senderUUID);
     void start();
@@ -66,6 +68,8 @@ private:
     QStringList _avatarWhitelist { };
     QString _replacementAvatar { REPLACEMENT_AVATAR_DEFAULT };
 
+    void optionallyReplicatePacket(ReceivedMessage& message, const Node& node);
+
     p_high_resolution_clock::time_point _lastFrameTimestamp;
 
     // FIXME - new throttling - use these values somehow
diff --git a/assignment-client/src/avatars/AvatarMixerSlave.cpp b/assignment-client/src/avatars/AvatarMixerSlave.cpp
index 2ad8bb58ed..8092518454 100644
--- a/assignment-client/src/avatars/AvatarMixerSlave.cpp
+++ b/assignment-client/src/avatars/AvatarMixerSlave.cpp
@@ -65,15 +65,32 @@ void AvatarMixerSlave::processIncomingPackets(const SharedNodePointer& node) {
     _stats.processIncomingPacketsElapsedTime += (end - start);
 }
 
-
 int AvatarMixerSlave::sendIdentityPacket(const AvatarMixerClientData* nodeData, const SharedNodePointer& destinationNode) {
-    QByteArray individualData = nodeData->getConstAvatarData()->identityByteArray();
-    individualData.replace(0, NUM_BYTES_RFC4122_UUID, nodeData->getNodeID().toRfc4122()); // FIXME, this looks suspicious
-    auto identityPackets = NLPacketList::create(PacketType::AvatarIdentity, QByteArray(), true, true);
-    identityPackets->write(individualData);
-    DependencyManager::get<NodeList>()->sendPacketList(std::move(identityPackets), *destinationNode);
-    _stats.numIdentityPackets++;
-    return individualData.size();
+    if (destinationNode->getType() == NodeType::Agent && !destinationNode->isUpstream()) {
+        QByteArray individualData = nodeData->getConstAvatarData()->identityByteArray();
+        individualData.replace(0, NUM_BYTES_RFC4122_UUID, nodeData->getNodeID().toRfc4122()); // FIXME, this looks suspicious
+        auto identityPackets = NLPacketList::create(PacketType::AvatarIdentity, QByteArray(), true, true);
+        identityPackets->write(individualData);
+        DependencyManager::get<NodeList>()->sendPacketList(std::move(identityPackets), *destinationNode);
+        _stats.numIdentityPackets++;
+        return individualData.size();
+    } else {
+        return 0;
+    }
+}
+
+int AvatarMixerSlave::sendReplicatedIdentityPacket(const AvatarMixerClientData* nodeData, const SharedNodePointer& destinationNode) {
+    if (destinationNode->getType() == NodeType::DownstreamAvatarMixer) {
+        QByteArray individualData = nodeData->getConstAvatarData()->identityByteArray();
+        individualData.replace(0, NUM_BYTES_RFC4122_UUID, nodeData->getNodeID().toRfc4122()); // FIXME, this looks suspicious
+        auto identityPacket = NLPacket::create(PacketType::ReplicatedAvatarIdentity);
+        identityPacket->write(individualData);
+        DependencyManager::get<NodeList>()->sendUnreliablePacket(*identityPacket, *destinationNode);
+        _stats.numIdentityPackets++;
+        return individualData.size();
+    } else {
+        return 0;
+    }
 }
 
 static const int AVATAR_MIXER_BROADCAST_FRAMES_PER_SECOND = 45;
@@ -81,6 +98,18 @@ static const int AVATAR_MIXER_BROADCAST_FRAMES_PER_SECOND = 45;
 void AvatarMixerSlave::broadcastAvatarData(const SharedNodePointer& node) {
     quint64 start = usecTimestampNow();
 
+    if (node->getType() == NodeType::Agent && node->getLinkedData() && node->getActiveSocket() && !node->isUpstream()) {
+        broadcastAvatarDataToAgent(node);
+    } else if (node->getType() == NodeType::DownstreamAvatarMixer) {
+        broadcastAvatarDataToDownstreamMixer(node);
+    }
+
+    quint64 end = usecTimestampNow();
+    _stats.jobElapsedTime += (end - start);
+}
+
+void AvatarMixerSlave::broadcastAvatarDataToAgent(const SharedNodePointer& node) {
+
     auto nodeList = DependencyManager::get<NodeList>();
 
     // setup for distributed random floating point values
@@ -88,308 +117,432 @@ void AvatarMixerSlave::broadcastAvatarData(const SharedNodePointer& node) {
     std::mt19937 generator(randomDevice());
     std::uniform_real_distribution<float> distribution;
 
-    if (node->getLinkedData() && (node->getType() == NodeType::Agent) && node->getActiveSocket()) {
-        _stats.nodesBroadcastedTo++;
+    _stats.nodesBroadcastedTo++;
 
-        AvatarMixerClientData* nodeData = reinterpret_cast<AvatarMixerClientData*>(node->getLinkedData());
+    AvatarMixerClientData* nodeData = reinterpret_cast<AvatarMixerClientData*>(node->getLinkedData());
 
-        nodeData->resetInViewStats();
+    nodeData->resetInViewStats();
 
-        const AvatarData& avatar = nodeData->getAvatar();
-        glm::vec3 myPosition = avatar.getClientGlobalPosition();
+    const AvatarData& avatar = nodeData->getAvatar();
+    glm::vec3 myPosition = avatar.getClientGlobalPosition();
 
-        // reset the internal state for correct random number distribution
-        distribution.reset();
+    // reset the internal state for correct random number distribution
+    distribution.reset();
 
-        // reset the number of sent avatars
-        nodeData->resetNumAvatarsSentLastFrame();
+    // reset the number of sent avatars
+    nodeData->resetNumAvatarsSentLastFrame();
 
-        // keep a counter of the number of considered avatars
-        int numOtherAvatars = 0;
+    // keep a counter of the number of considered avatars
+    int numOtherAvatars = 0;
 
-        // keep track of outbound data rate specifically for avatar data
-        int numAvatarDataBytes = 0;
-        int identityBytesSent = 0;
+    // keep track of outbound data rate specifically for avatar data
+    int numAvatarDataBytes = 0;
+    int identityBytesSent = 0;
 
-        // max number of avatarBytes per frame
-        auto maxAvatarBytesPerFrame = (_maxKbpsPerNode * BYTES_PER_KILOBIT) / AVATAR_MIXER_BROADCAST_FRAMES_PER_SECOND;
+    // max number of avatarBytes per frame
+    auto maxAvatarBytesPerFrame = (_maxKbpsPerNode * BYTES_PER_KILOBIT) / AVATAR_MIXER_BROADCAST_FRAMES_PER_SECOND;
 
-        // FIXME - find a way to not send the sessionID for every avatar
-        int minimumBytesPerAvatar = AvatarDataPacket::AVATAR_HAS_FLAGS_SIZE + NUM_BYTES_RFC4122_UUID;
+    // FIXME - find a way to not send the sessionID for every avatar
+    int minimumBytesPerAvatar = AvatarDataPacket::AVATAR_HAS_FLAGS_SIZE + NUM_BYTES_RFC4122_UUID;
 
-        int overBudgetAvatars = 0;
+    int overBudgetAvatars = 0;
 
-        // keep track of the number of other avatars held back in this frame
-        int numAvatarsHeldBack = 0;
+    // keep track of the number of other avatars held back in this frame
+    int numAvatarsHeldBack = 0;
 
-        // keep track of the number of other avatar frames skipped
-        int numAvatarsWithSkippedFrames = 0;
+    // keep track of the number of other avatar frames skipped
+    int numAvatarsWithSkippedFrames = 0;
 
-        // When this is true, the AvatarMixer will send Avatar data to a client
-        // about avatars they've ignored or that are out of view
-        bool PALIsOpen = nodeData->getRequestsDomainListData();
+    // When this is true, the AvatarMixer will send Avatar data to a client
+    // about avatars they've ignored or that are out of view
+    bool PALIsOpen = nodeData->getRequestsDomainListData();
 
-        // When this is true, the AvatarMixer will send Avatar data to a client about avatars that have ignored them
-        bool getsAnyIgnored = PALIsOpen && node->getCanKick();
+    // When this is true, the AvatarMixer will send Avatar data to a client about avatars that have ignored them
+    bool getsAnyIgnored = PALIsOpen && node->getCanKick();
 
-        if (PALIsOpen) {
-            // Increase minimumBytesPerAvatar if the PAL is open
-            minimumBytesPerAvatar += sizeof(AvatarDataPacket::AvatarGlobalPosition) +
-                sizeof(AvatarDataPacket::AudioLoudness);
-        }
+    if (PALIsOpen) {
+        // Increase minimumBytesPerAvatar if the PAL is open
+        minimumBytesPerAvatar += sizeof(AvatarDataPacket::AvatarGlobalPosition) +
+        sizeof(AvatarDataPacket::AudioLoudness);
+    }
 
-        // setup a PacketList for the avatarPackets
-        auto avatarPacketList = NLPacketList::create(PacketType::BulkAvatarData);
+    // setup a PacketList for the avatarPackets
+    auto avatarPacketList = NLPacketList::create(PacketType::BulkAvatarData);
 
-        // Define the minimum bubble size
-        static const glm::vec3 minBubbleSize = glm::vec3(0.3f, 1.3f, 0.3f);
-        // Define the scale of the box for the current node
-        glm::vec3 nodeBoxScale = (nodeData->getPosition() - nodeData->getGlobalBoundingBoxCorner()) * 2.0f;
-        // Set up the bounding box for the current node
-        AABox nodeBox(nodeData->getGlobalBoundingBoxCorner(), nodeBoxScale);
-        // Clamp the size of the bounding box to a minimum scale
-        if (glm::any(glm::lessThan(nodeBoxScale, minBubbleSize))) {
-            nodeBox.setScaleStayCentered(minBubbleSize);
-        }
-        // Quadruple the scale of both bounding boxes
-        nodeBox.embiggen(4.0f);
+    // Define the minimum bubble size
+    static const glm::vec3 minBubbleSize = glm::vec3(0.3f, 1.3f, 0.3f);
+    // Define the scale of the box for the current node
+    glm::vec3 nodeBoxScale = (nodeData->getPosition() - nodeData->getGlobalBoundingBoxCorner()) * 2.0f;
+    // Set up the bounding box for the current node
+    AABox nodeBox(nodeData->getGlobalBoundingBoxCorner(), nodeBoxScale);
+    // Clamp the size of the bounding box to a minimum scale
+    if (glm::any(glm::lessThan(nodeBoxScale, minBubbleSize))) {
+        nodeBox.setScaleStayCentered(minBubbleSize);
+    }
+    // Quadruple the scale of both bounding boxes
+    nodeBox.embiggen(4.0f);
 
 
-        // setup list of AvatarData as well as maps to map betweeen the AvatarData and the original nodes
-        // for calling the AvatarData::sortAvatars() function and getting our sorted list of client nodes
-        QList<AvatarSharedPointer> avatarList;
-        std::unordered_map<AvatarSharedPointer, SharedNodePointer> avatarDataToNodes;
+    // setup list of AvatarData as well as maps to map betweeen the AvatarData and the original nodes
+    // for calling the AvatarData::sortAvatars() function and getting our sorted list of client nodes
+    QList<AvatarSharedPointer> avatarList;
+    std::unordered_map<AvatarSharedPointer, SharedNodePointer> avatarDataToNodes;
 
-        std::for_each(_begin, _end, [&](const SharedNodePointer& otherNode) {
+    std::for_each(_begin, _end, [&](const SharedNodePointer& otherNode) {
+        // make sure this is an agent that we have avatar data for before considering it for inclusion
+        if (otherNode->getType() == NodeType::Agent
+            && otherNode->getLinkedData()) {
             const AvatarMixerClientData* otherNodeData = reinterpret_cast<const AvatarMixerClientData*>(otherNode->getLinkedData());
 
-            // theoretically it's possible for a Node to be in the NodeList (and therefore end up here),
-            // but not have yet sent data that's linked to the node. Check for that case and don't
-            // consider those nodes.
-            if (otherNodeData) {
-                AvatarSharedPointer otherAvatar = otherNodeData->getAvatarSharedPointer();
-                avatarList << otherAvatar;
-                avatarDataToNodes[otherAvatar] = otherNode;
+            AvatarSharedPointer otherAvatar = otherNodeData->getAvatarSharedPointer();
+            avatarList << otherAvatar;
+            avatarDataToNodes[otherAvatar] = otherNode;
+        }
+    });
+
+    AvatarSharedPointer thisAvatar = nodeData->getAvatarSharedPointer();
+    ViewFrustum cameraView = nodeData->getViewFrustom();
+    std::priority_queue<AvatarPriority> sortedAvatars;
+    AvatarData::sortAvatars(avatarList, cameraView, sortedAvatars,
+                            [&](AvatarSharedPointer avatar)->uint64_t {
+        auto avatarNode = avatarDataToNodes[avatar];
+        assert(avatarNode); // we can't have gotten here without the avatarData being a valid key in the map
+        return nodeData->getLastBroadcastTime(avatarNode->getUUID());
+    }, [&](AvatarSharedPointer avatar)->float{
+        glm::vec3 nodeBoxHalfScale = (avatar->getPosition() - avatar->getGlobalBoundingBoxCorner());
+        return glm::max(nodeBoxHalfScale.x, glm::max(nodeBoxHalfScale.y, nodeBoxHalfScale.z));
+    }, [&](AvatarSharedPointer avatar)->bool {
+        if (avatar == thisAvatar) {
+            return true; // ignore ourselves...
+        }
+
+        bool shouldIgnore = false;
+
+        // We will also ignore other nodes for a couple of different reasons:
+        //   1) ignore bubbles and ignore specific node
+        //   2) the node hasn't really updated it's frame data recently, this can
+        //      happen if for example the avatar is connected on a desktop and sending
+        //      updates at ~30hz. So every 3 frames we skip a frame.
+        auto avatarNode = avatarDataToNodes[avatar];
+
+        assert(avatarNode); // we can't have gotten here without the avatarData being a valid key in the map
+
+        const AvatarMixerClientData* avatarNodeData = reinterpret_cast<const AvatarMixerClientData*>(avatarNode->getLinkedData());
+        assert(avatarNodeData); // we can't have gotten here without avatarNode having valid data
+        quint64 startIgnoreCalculation = usecTimestampNow();
+
+        // make sure we have data for this avatar, that it isn't the same node,
+        // and isn't an avatar that the viewing node has ignored
+        // or that has ignored the viewing node
+        if (!avatarNode->getLinkedData()
+            || avatarNode->getUUID() == node->getUUID()
+            || (node->isIgnoringNodeWithID(avatarNode->getUUID()) && !PALIsOpen)
+            || (avatarNode->isIgnoringNodeWithID(node->getUUID()) && !getsAnyIgnored)) {
+            shouldIgnore = true;
+        } else {
+
+            // Check to see if the space bubble is enabled
+            // Don't bother with these checks if the other avatar has their bubble enabled and we're gettingAnyIgnored
+            if (node->isIgnoreRadiusEnabled() || (avatarNode->isIgnoreRadiusEnabled() && !getsAnyIgnored)) {
+
+                // Define the scale of the box for the current other node
+                glm::vec3 otherNodeBoxScale = (avatarNodeData->getPosition() - avatarNodeData->getGlobalBoundingBoxCorner()) * 2.0f;
+                // Set up the bounding box for the current other node
+                AABox otherNodeBox(avatarNodeData->getGlobalBoundingBoxCorner(), otherNodeBoxScale);
+                // Clamp the size of the bounding box to a minimum scale
+                if (glm::any(glm::lessThan(otherNodeBoxScale, minBubbleSize))) {
+                    otherNodeBox.setScaleStayCentered(minBubbleSize);
+                }
+                // Quadruple the scale of both bounding boxes
+                otherNodeBox.embiggen(4.0f);
+
+                // Perform the collision check between the two bounding boxes
+                if (nodeBox.touches(otherNodeBox)) {
+                    nodeData->ignoreOther(node, avatarNode);
+                    shouldIgnore = !getsAnyIgnored;
+                }
             }
-        });
+            // Not close enough to ignore
+            if (!shouldIgnore) {
+                nodeData->removeFromRadiusIgnoringSet(node, avatarNode->getUUID());
+            }
+        }
+        quint64 endIgnoreCalculation = usecTimestampNow();
+        _stats.ignoreCalculationElapsedTime += (endIgnoreCalculation - startIgnoreCalculation);
 
-        AvatarSharedPointer thisAvatar = nodeData->getAvatarSharedPointer();
-        ViewFrustum cameraView = nodeData->getViewFrustom();
-        std::priority_queue<AvatarPriority> sortedAvatars;
-        AvatarData::sortAvatars(avatarList, cameraView, sortedAvatars,
+        if (!shouldIgnore) {
+            AvatarDataSequenceNumber lastSeqToReceiver = nodeData->getLastBroadcastSequenceNumber(avatarNode->getUUID());
+            AvatarDataSequenceNumber lastSeqFromSender = avatarNodeData->getLastReceivedSequenceNumber();
 
-                [&](AvatarSharedPointer avatar)->uint64_t{
-                    auto avatarNode = avatarDataToNodes[avatar];
-                    assert(avatarNode); // we can't have gotten here without the avatarData being a valid key in the map
-                    return nodeData->getLastBroadcastTime(avatarNode->getUUID());
-                },
+            // FIXME - This code does appear to be working. But it seems brittle.
+            //         It supports determining if the frame of data for this "other"
+            //         avatar has already been sent to the reciever. This has been
+            //         verified to work on a desktop display that renders at 60hz and
+            //         therefore sends to mixer at 30hz. Each second you'd expect to
+            //         have 15 (45hz-30hz) duplicate frames. In this case, the stat
+            //         avg_other_av_skips_per_second does report 15.
+            //
+            // make sure we haven't already sent this data from this sender to this receiver
+            // or that somehow we haven't sent
+            if (lastSeqToReceiver == lastSeqFromSender && lastSeqToReceiver != 0) {
+                ++numAvatarsHeldBack;
+                shouldIgnore = true;
+            } else if (lastSeqFromSender - lastSeqToReceiver > 1) {
+                // this is a skip - we still send the packet but capture the presence of the skip so we see it happening
+                ++numAvatarsWithSkippedFrames;
+            }
+        }
+        return shouldIgnore;
+    });
 
-                [&](AvatarSharedPointer avatar)->float{
-                    glm::vec3 nodeBoxHalfScale = (avatar->getPosition() - avatar->getGlobalBoundingBoxCorner());
-                    return glm::max(nodeBoxHalfScale.x, glm::max(nodeBoxHalfScale.y, nodeBoxHalfScale.z));
-                },
+    // loop through our sorted avatars and allocate our bandwidth to them accordingly
+    int avatarRank = 0;
 
-                [&](AvatarSharedPointer avatar)->bool{
-                    if (avatar == thisAvatar) {
-                        return true; // ignore ourselves...
-                    }
+    // this is overly conservative, because it includes some avatars we might not consider
+    int remainingAvatars = (int)sortedAvatars.size();
 
-                    bool shouldIgnore = false;
+    while (!sortedAvatars.empty()) {
+        AvatarPriority sortData = sortedAvatars.top();
+        sortedAvatars.pop();
+        const auto& avatarData = sortData.avatar;
+        avatarRank++;
+        remainingAvatars--;
 
-                    // We will also ignore other nodes for a couple of different reasons:
-                    //   1) ignore bubbles and ignore specific node
-                    //   2) the node hasn't really updated it's frame data recently, this can
-                    //      happen if for example the avatar is connected on a desktop and sending
-                    //      updates at ~30hz. So every 3 frames we skip a frame.
-                    auto avatarNode = avatarDataToNodes[avatar];
+        auto otherNode = avatarDataToNodes[avatarData];
+        assert(otherNode); // we can't have gotten here without the avatarData being a valid key in the map
 
-                    assert(avatarNode); // we can't have gotten here without the avatarData being a valid key in the map
+        // NOTE: Here's where we determine if we are over budget and drop to bare minimum data
+        int minimRemainingAvatarBytes = minimumBytesPerAvatar * remainingAvatars;
+        bool overBudget = (identityBytesSent + numAvatarDataBytes + minimRemainingAvatarBytes) > maxAvatarBytesPerFrame;
 
-                    const AvatarMixerClientData* avatarNodeData = reinterpret_cast<const AvatarMixerClientData*>(avatarNode->getLinkedData());
-                    assert(avatarNodeData); // we can't have gotten here without avatarNode having valid data
-                    quint64 startIgnoreCalculation = usecTimestampNow();
+        quint64 startAvatarDataPacking = usecTimestampNow();
 
-                    // make sure we have data for this avatar, that it isn't the same node,
-                    // and isn't an avatar that the viewing node has ignored
-                    // or that has ignored the viewing node
-                    if (!avatarNode->getLinkedData()
-                        || avatarNode->getUUID() == node->getUUID()
-                        || (node->isIgnoringNodeWithID(avatarNode->getUUID()) && !PALIsOpen)
-                        || (avatarNode->isIgnoringNodeWithID(node->getUUID()) && !getsAnyIgnored)) {
-                        shouldIgnore = true;
-                    } else {
+        ++numOtherAvatars;
 
-                        // Check to see if the space bubble is enabled
-                        // Don't bother with these checks if the other avatar has their bubble enabled and we're gettingAnyIgnored
-                        if (node->isIgnoreRadiusEnabled() || (avatarNode->isIgnoreRadiusEnabled() && !getsAnyIgnored)) {
+        const AvatarMixerClientData* otherNodeData = reinterpret_cast<const AvatarMixerClientData*>(otherNode->getLinkedData());
 
-                            // Define the scale of the box for the current other node
-                            glm::vec3 otherNodeBoxScale = (avatarNodeData->getPosition() - avatarNodeData->getGlobalBoundingBoxCorner()) * 2.0f;
-                            // Set up the bounding box for the current other node
-                            AABox otherNodeBox(avatarNodeData->getGlobalBoundingBoxCorner(), otherNodeBoxScale);
-                            // Clamp the size of the bounding box to a minimum scale
-                            if (glm::any(glm::lessThan(otherNodeBoxScale, minBubbleSize))) {
-                                otherNodeBox.setScaleStayCentered(minBubbleSize);
-                            }
-                            // Quadruple the scale of both bounding boxes
-                            otherNodeBox.embiggen(4.0f);
+        // If the time that the mixer sent AVATAR DATA about Avatar B to Avatar A is BEFORE OR EQUAL TO
+        // the time that Avatar B flagged an IDENTITY DATA change, send IDENTITY DATA about Avatar B to Avatar A.
+        if (nodeData->getLastBroadcastTime(otherNode->getUUID()) <= otherNodeData->getIdentityChangeTimestamp()) {
+            identityBytesSent += sendIdentityPacket(otherNodeData, node);
+        }
 
-                            // Perform the collision check between the two bounding boxes
-                            if (nodeBox.touches(otherNodeBox)) {
-                                nodeData->ignoreOther(node, avatarNode);
-                                shouldIgnore = !getsAnyIgnored;
-                            }
-                        }
-                        // Not close enough to ignore
-                        if (!shouldIgnore) {
-                            nodeData->removeFromRadiusIgnoringSet(node, avatarNode->getUUID());
-                        }
-                    }
-                    quint64 endIgnoreCalculation = usecTimestampNow();
-                    _stats.ignoreCalculationElapsedTime += (endIgnoreCalculation - startIgnoreCalculation);
+        const AvatarData* otherAvatar = otherNodeData->getConstAvatarData();
+        glm::vec3 otherPosition = otherAvatar->getClientGlobalPosition();
 
-                    if (!shouldIgnore) {
-                        AvatarDataSequenceNumber lastSeqToReceiver = nodeData->getLastBroadcastSequenceNumber(avatarNode->getUUID());
-                        AvatarDataSequenceNumber lastSeqFromSender = avatarNodeData->getLastReceivedSequenceNumber();
+        // determine if avatar is in view, to determine how much data to include...
+        glm::vec3 otherNodeBoxScale = (otherPosition - otherNodeData->getGlobalBoundingBoxCorner()) * 2.0f;
+        AABox otherNodeBox(otherNodeData->getGlobalBoundingBoxCorner(), otherNodeBoxScale);
+        bool isInView = nodeData->otherAvatarInView(otherNodeBox);
 
-                        // FIXME - This code does appear to be working. But it seems brittle.
-                        //         It supports determining if the frame of data for this "other"
-                        //         avatar has already been sent to the reciever. This has been
-                        //         verified to work on a desktop display that renders at 60hz and
-                        //         therefore sends to mixer at 30hz. Each second you'd expect to
-                        //         have 15 (45hz-30hz) duplicate frames. In this case, the stat
-                        //         avg_other_av_skips_per_second does report 15.
-                        //
-                        // make sure we haven't already sent this data from this sender to this receiver
-                        // or that somehow we haven't sent
-                        if (lastSeqToReceiver == lastSeqFromSender && lastSeqToReceiver != 0) {
-                            ++numAvatarsHeldBack;
-                            shouldIgnore = true;
-                        } else if (lastSeqFromSender - lastSeqToReceiver > 1) {
-                            // this is a skip - we still send the packet but capture the presence of the skip so we see it happening
-                            ++numAvatarsWithSkippedFrames;
-                        }
-                    }
-                    return shouldIgnore;
-                });
+        // start a new segment in the PacketList for this avatar
+        avatarPacketList->startSegment();
 
-        // loop through our sorted avatars and allocate our bandwidth to them accordingly
-        int avatarRank = 0;
+        AvatarData::AvatarDataDetail detail;
 
-        // this is overly conservative, because it includes some avatars we might not consider
-        int remainingAvatars = (int)sortedAvatars.size();
+        if (overBudget) {
+            overBudgetAvatars++;
+            _stats.overBudgetAvatars++;
+            detail = PALIsOpen ? AvatarData::PALMinimum : AvatarData::NoData;
+        } else if (!isInView) {
+            detail = PALIsOpen ? AvatarData::PALMinimum : AvatarData::MinimumData;
+            nodeData->incrementAvatarOutOfView();
+        } else {
+            detail = distribution(generator) < AVATAR_SEND_FULL_UPDATE_RATIO
+            ? AvatarData::SendAllData : AvatarData::CullSmallData;
+            nodeData->incrementAvatarInView();
+        }
 
-        while (!sortedAvatars.empty()) {
-            AvatarPriority sortData = sortedAvatars.top();
-            sortedAvatars.pop();
-            const auto& avatarData = sortData.avatar;
-            avatarRank++;
-            remainingAvatars--;
+        bool includeThisAvatar = true;
+        auto lastEncodeForOther = nodeData->getLastOtherAvatarEncodeTime(otherNode->getUUID());
+        QVector<JointData>& lastSentJointsForOther = nodeData->getLastOtherAvatarSentJoints(otherNode->getUUID());
+        bool distanceAdjust = true;
+        glm::vec3 viewerPosition = myPosition;
+        AvatarDataPacket::HasFlags hasFlagsOut; // the result of the toByteArray
+        bool dropFaceTracking = false;
 
-            auto otherNode = avatarDataToNodes[avatarData];
-            assert(otherNode); // we can't have gotten here without the avatarData being a valid key in the map
+        quint64 start = usecTimestampNow();
+        QByteArray bytes = otherAvatar->toByteArray(detail, lastEncodeForOther, lastSentJointsForOther,
+                                                    hasFlagsOut, dropFaceTracking, distanceAdjust, viewerPosition, &lastSentJointsForOther);
+        quint64 end = usecTimestampNow();
+        _stats.toByteArrayElapsedTime += (end - start);
 
-            // NOTE: Here's where we determine if we are over budget and drop to bare minimum data
-            int minimRemainingAvatarBytes = minimumBytesPerAvatar * remainingAvatars;
-            bool overBudget = (identityBytesSent + numAvatarDataBytes + minimRemainingAvatarBytes) > maxAvatarBytesPerFrame;
+        static const int MAX_ALLOWED_AVATAR_DATA = (1400 - NUM_BYTES_RFC4122_UUID);
+        if (bytes.size() > MAX_ALLOWED_AVATAR_DATA) {
+            qCWarning(avatars) << "otherAvatar.toByteArray() resulted in very large buffer:" << bytes.size() << "... attempt to drop facial data";
+
+            dropFaceTracking = true; // first try dropping the facial data
+            bytes = otherAvatar->toByteArray(detail, lastEncodeForOther, lastSentJointsForOther,
+                                             hasFlagsOut, dropFaceTracking, distanceAdjust, viewerPosition, &lastSentJointsForOther);
+
+            if (bytes.size() > MAX_ALLOWED_AVATAR_DATA) {
+                qCWarning(avatars) << "otherAvatar.toByteArray() without facial data resulted in very large buffer:" << bytes.size() << "... reduce to MinimumData";
+                bytes = otherAvatar->toByteArray(AvatarData::MinimumData, lastEncodeForOther, lastSentJointsForOther,
+                                                 hasFlagsOut, dropFaceTracking, distanceAdjust, viewerPosition, &lastSentJointsForOther);
+            }
+
+            if (bytes.size() > MAX_ALLOWED_AVATAR_DATA) {
+                qCWarning(avatars) << "otherAvatar.toByteArray() MinimumData resulted in very large buffer:" << bytes.size() << "... FAIL!!";
+                includeThisAvatar = false;
+            }
+        }
+
+        if (includeThisAvatar) {
+            numAvatarDataBytes += avatarPacketList->write(otherNode->getUUID().toRfc4122());
+            numAvatarDataBytes += avatarPacketList->write(bytes);
+
+            if (detail != AvatarData::NoData) {
+                _stats.numOthersIncluded++;
+
+                // increment the number of avatars sent to this reciever
+                nodeData->incrementNumAvatarsSentLastFrame();
+
+                // set the last sent sequence number for this sender on the receiver
+                nodeData->setLastBroadcastSequenceNumber(otherNode->getUUID(),
+                                                         otherNodeData->getLastReceivedSequenceNumber());
+
+                // remember the last time we sent details about this other node to the receiver
+                nodeData->setLastBroadcastTime(otherNode->getUUID(), start);
+            }
+        }
+
+        avatarPacketList->endSegment();
+
+        quint64 endAvatarDataPacking = usecTimestampNow();
+        _stats.avatarDataPackingElapsedTime += (endAvatarDataPacking - startAvatarDataPacking);
+    };
+
+    quint64 startPacketSending = usecTimestampNow();
+
+    // close the current packet so that we're always sending something
+    avatarPacketList->closeCurrentPacket(true);
+
+    _stats.numPacketsSent += (int)avatarPacketList->getNumPackets();
+    _stats.numBytesSent += numAvatarDataBytes;
+
+    // send the avatar data PacketList
+    nodeList->sendPacketList(std::move(avatarPacketList), *node);
+
+    // record the bytes sent for other avatar data in the AvatarMixerClientData
+    nodeData->recordSentAvatarData(numAvatarDataBytes);
+
+    // record the number of avatars held back this frame
+    nodeData->recordNumOtherAvatarStarves(numAvatarsHeldBack);
+    nodeData->recordNumOtherAvatarSkips(numAvatarsWithSkippedFrames);
+
+    quint64 endPacketSending = usecTimestampNow();
+    _stats.packetSendingElapsedTime += (endPacketSending - startPacketSending);
+}
+
+uint64_t REBROADCAST_IDENTITY_TO_DOWNSTREAM_EVERY_US = 5 * 1000 * 1000;
+
+void AvatarMixerSlave::broadcastAvatarDataToDownstreamMixer(const SharedNodePointer& node) {
+    _stats.downstreamMixersBroadcastedTo++;
+
+    AvatarMixerClientData* nodeData = reinterpret_cast<AvatarMixerClientData*>(node->getLinkedData());
+    if (!nodeData) {
+        return;
+    }
+
+    // setup a PacketList for the replicated bulk avatar data
+    auto avatarPacketList = NLPacketList::create(PacketType::ReplicatedBulkAvatarData);
+
+    int numAvatarDataBytes = 0;
+
+    // reset the number of sent avatars
+    nodeData->resetNumAvatarsSentLastFrame();
+
+    std::for_each(_begin, _end, [&](const SharedNodePointer& agentNode) {
+        // collect agents that we have avatar data for that we are supposed to replicate
+        if (agentNode->getType() == NodeType::Agent && agentNode->getLinkedData() && agentNode->isReplicated()) {
+            const AvatarMixerClientData* agentNodeData = reinterpret_cast<const AvatarMixerClientData*>(agentNode->getLinkedData());
+
+            AvatarSharedPointer otherAvatar = agentNodeData->getAvatarSharedPointer();
 
             quint64 startAvatarDataPacking = usecTimestampNow();
 
-            ++numOtherAvatars;
-
-            const AvatarMixerClientData* otherNodeData = reinterpret_cast<const AvatarMixerClientData*>(otherNode->getLinkedData());
-
-            // If the time that the mixer sent AVATAR DATA about Avatar B to Avatar A is BEFORE OR EQUAL TO
-            // the time that Avatar B flagged an IDENTITY DATA change, send IDENTITY DATA about Avatar B to Avatar A.
-            if (nodeData->getLastBroadcastTime(otherNode->getUUID()) <= otherNodeData->getIdentityChangeTimestamp()) {
-                identityBytesSent += sendIdentityPacket(otherNodeData, node);
-            }
-
-            const AvatarData* otherAvatar = otherNodeData->getConstAvatarData();
-            glm::vec3 otherPosition = otherAvatar->getClientGlobalPosition();
-
-            // determine if avatar is in view, to determine how much data to include...
-            glm::vec3 otherNodeBoxScale = (otherPosition - otherNodeData->getGlobalBoundingBoxCorner()) * 2.0f;
-            AABox otherNodeBox(otherNodeData->getGlobalBoundingBoxCorner(), otherNodeBoxScale);
-            bool isInView = nodeData->otherAvatarInView(otherNodeBox);
-
-            // start a new segment in the PacketList for this avatar
-            avatarPacketList->startSegment();
-
-            AvatarData::AvatarDataDetail detail;
-
-            if (overBudget) {
-                overBudgetAvatars++;
-                _stats.overBudgetAvatars++;
-                detail = PALIsOpen ? AvatarData::PALMinimum : AvatarData::NoData;
-            } else if (!isInView) {
-                detail = PALIsOpen ? AvatarData::PALMinimum : AvatarData::MinimumData;
-                nodeData->incrementAvatarOutOfView();
-            } else {
-                detail = distribution(generator) < AVATAR_SEND_FULL_UPDATE_RATIO
-                    ? AvatarData::SendAllData : AvatarData::CullSmallData;
-                nodeData->incrementAvatarInView();
-            }
-
-            bool includeThisAvatar = true;
-            auto lastEncodeForOther = nodeData->getLastOtherAvatarEncodeTime(otherNode->getUUID());
-            QVector<JointData>& lastSentJointsForOther = nodeData->getLastOtherAvatarSentJoints(otherNode->getUUID());
-            bool distanceAdjust = true;
-            glm::vec3 viewerPosition = myPosition;
-            AvatarDataPacket::HasFlags hasFlagsOut; // the result of the toByteArray
-            bool dropFaceTracking = false;
+            // we cannot send a downstream avatar mixer any updates that expect them to have previous state for this avatar
+            // since we have no idea if they're online and receiving our packets
 
+            // so we always send a full update for this avatar
+            
             quint64 start = usecTimestampNow();
-            QByteArray bytes = otherAvatar->toByteArray(detail, lastEncodeForOther, lastSentJointsForOther, 
-                                            hasFlagsOut, dropFaceTracking, distanceAdjust, viewerPosition, &lastSentJointsForOther);
+            AvatarDataPacket::HasFlags flagsOut;
+
+            QVector<JointData> emptyLastJointSendData { otherAvatar->getJointCount() };
+
+            QByteArray avatarByteArray = otherAvatar->toByteArray(AvatarData::SendAllData, 0, emptyLastJointSendData,
+                                                                  flagsOut, false, false, glm::vec3(0), nullptr);
             quint64 end = usecTimestampNow();
             _stats.toByteArrayElapsedTime += (end - start);
 
-            static const int MAX_ALLOWED_AVATAR_DATA = (1400 - NUM_BYTES_RFC4122_UUID);
-            if (bytes.size() > MAX_ALLOWED_AVATAR_DATA) {
-                qCWarning(avatars) << "otherAvatar.toByteArray() resulted in very large buffer:" << bytes.size() << "... attempt to drop facial data";
+            auto lastBroadcastTime = nodeData->getLastBroadcastTime(agentNode->getUUID());
+            if (lastBroadcastTime <= agentNodeData->getIdentityChangeTimestamp()
+                || (start - lastBroadcastTime) >= REBROADCAST_IDENTITY_TO_DOWNSTREAM_EVERY_US) {
+                sendReplicatedIdentityPacket(agentNodeData, node);
+                nodeData->setLastBroadcastTime(agentNode->getUUID(), start);
+            }
 
-                dropFaceTracking = true; // first try dropping the facial data
-                bytes = otherAvatar->toByteArray(detail, lastEncodeForOther, lastSentJointsForOther,
-                    hasFlagsOut, dropFaceTracking, distanceAdjust, viewerPosition, &lastSentJointsForOther);
+            // figure out how large our avatar byte array can be to fit in the packet list
+            // given that we need it and the avatar UUID and the size of the byte array (16 bit)
+            // to fit in a segment of the packet list
+            auto maxAvatarByteArraySize = avatarPacketList->getMaxSegmentSize();
+            maxAvatarByteArraySize -= NUM_BYTES_RFC4122_UUID;
+            maxAvatarByteArraySize -= sizeof(quint16);
 
-                if (bytes.size() > MAX_ALLOWED_AVATAR_DATA) {
-                    qCWarning(avatars) << "otherAvatar.toByteArray() without facial data resulted in very large buffer:" << bytes.size() << "... reduce to MinimumData";
-                    bytes = otherAvatar->toByteArray(AvatarData::MinimumData, lastEncodeForOther, lastSentJointsForOther,
-                        hasFlagsOut, dropFaceTracking, distanceAdjust, viewerPosition, &lastSentJointsForOther);
-                }
+            auto sequenceNumberSize = sizeof(agentNodeData->getLastReceivedSequenceNumber());
+            maxAvatarByteArraySize -= sequenceNumberSize;
 
-                if (bytes.size() > MAX_ALLOWED_AVATAR_DATA) {
-                    qCWarning(avatars) << "otherAvatar.toByteArray() MinimumData resulted in very large buffer:" << bytes.size() << "... FAIL!!";
-                    includeThisAvatar = false;
+            if (avatarByteArray.size() > maxAvatarByteArraySize) {
+                qCWarning(avatars) << "Replicated avatar data too large for" << otherAvatar->getSessionUUID()
+                    << "-" << avatarByteArray.size() << "bytes";
+
+                avatarByteArray = otherAvatar->toByteArray(AvatarData::SendAllData, 0, emptyLastJointSendData,
+                                                           flagsOut, true, false, glm::vec3(0), nullptr);
+
+                if (avatarByteArray.size() > maxAvatarByteArraySize) {
+                    qCWarning(avatars) << "Replicated avatar data without facial data still too large for"
+                        << otherAvatar->getSessionUUID() << "-" << avatarByteArray.size() << "bytes";
+
+                    avatarByteArray = otherAvatar->toByteArray(AvatarData::MinimumData, 0, emptyLastJointSendData,
+                                                               flagsOut, true, false, glm::vec3(0), nullptr);
                 }
             }
 
-            if (includeThisAvatar) {
-                numAvatarDataBytes += avatarPacketList->write(otherNode->getUUID().toRfc4122());
-                numAvatarDataBytes += avatarPacketList->write(bytes);
+            if (avatarByteArray.size() <= maxAvatarByteArraySize) {
+                // increment the number of avatars sent to this reciever
+                nodeData->incrementNumAvatarsSentLastFrame();
 
-                if (detail != AvatarData::NoData) {
-                    _stats.numOthersIncluded++;
+                // set the last sent sequence number for this sender on the receiver
+                nodeData->setLastBroadcastSequenceNumber(agentNode->getUUID(),
+                                                         agentNodeData->getLastReceivedSequenceNumber());
 
-                    // increment the number of avatars sent to this reciever
-                    nodeData->incrementNumAvatarsSentLastFrame();
+                // increment the number of avatars sent to this reciever
+                nodeData->incrementNumAvatarsSentLastFrame();
 
-                    // set the last sent sequence number for this sender on the receiver
-                    nodeData->setLastBroadcastSequenceNumber(otherNode->getUUID(), 
-                                    otherNodeData->getLastReceivedSequenceNumber());
+                // start a new segment in the packet list for this avatar
+                avatarPacketList->startSegment();
 
-                    // remember the last time we sent details about this other node to the receiver
-                    nodeData->setLastBroadcastTime(otherNode->getUUID(), start);
-                }
+                // write the node's UUID, the size of the replicated avatar data,
+                // the sequence number of the replicated avatar data, and the replicated avatar data
+                numAvatarDataBytes += avatarPacketList->write(agentNode->getUUID().toRfc4122());
+                numAvatarDataBytes += avatarPacketList->writePrimitive((quint16) (avatarByteArray.size() + sequenceNumberSize));
+                numAvatarDataBytes += avatarPacketList->writePrimitive(agentNodeData->getLastReceivedSequenceNumber());
+                numAvatarDataBytes += avatarPacketList->write(avatarByteArray);
+
+                avatarPacketList->endSegment();
+
+            } else {
+                qCWarning(avatars) << "Could not fit minimum data avatar for" << otherAvatar->getSessionUUID()
+                    << "to packet list -" << avatarByteArray.size() << "bytes";
             }
 
-            avatarPacketList->endSegment();
-
             quint64 endAvatarDataPacking = usecTimestampNow();
             _stats.avatarDataPackingElapsedTime += (endAvatarDataPacking - startAvatarDataPacking);
-        };
+        }
+    });
 
+    if (avatarPacketList->getNumPackets() > 0) {
         quint64 startPacketSending = usecTimestampNow();
 
         // close the current packet so that we're always sending something
@@ -398,21 +551,15 @@ void AvatarMixerSlave::broadcastAvatarData(const SharedNodePointer& node) {
         _stats.numPacketsSent += (int)avatarPacketList->getNumPackets();
         _stats.numBytesSent += numAvatarDataBytes;
 
-        // send the avatar data PacketList
-        nodeList->sendPacketList(std::move(avatarPacketList), *node);
+        // send the replicated bulk avatar data
+        auto nodeList = DependencyManager::get<NodeList>();
+        nodeList->sendPacketList(std::move(avatarPacketList), node->getPublicSocket());
 
         // record the bytes sent for other avatar data in the AvatarMixerClientData
         nodeData->recordSentAvatarData(numAvatarDataBytes);
 
-        // record the number of avatars held back this frame
-        nodeData->recordNumOtherAvatarStarves(numAvatarsHeldBack);
-        nodeData->recordNumOtherAvatarSkips(numAvatarsWithSkippedFrames);
-
         quint64 endPacketSending = usecTimestampNow();
         _stats.packetSendingElapsedTime += (endPacketSending - startPacketSending);
     }
-
-    quint64 end = usecTimestampNow();
-    _stats.jobElapsedTime += (end - start);
 }
 
diff --git a/assignment-client/src/avatars/AvatarMixerSlave.h b/assignment-client/src/avatars/AvatarMixerSlave.h
index 04141d9d72..69c707bbf1 100644
--- a/assignment-client/src/avatars/AvatarMixerSlave.h
+++ b/assignment-client/src/avatars/AvatarMixerSlave.h
@@ -21,6 +21,7 @@ public:
     quint64 processIncomingPacketsElapsedTime { 0 };
 
     int nodesBroadcastedTo { 0 };
+    int downstreamMixersBroadcastedTo { 0 };
     int numPacketsSent { 0 };
     int numBytesSent { 0 };
     int numIdentityPackets { 0 };
@@ -41,6 +42,7 @@ public:
 
         // sending job stats
         nodesBroadcastedTo = 0;
+        downstreamMixersBroadcastedTo = 0;
         numPacketsSent = 0;
         numBytesSent = 0;
         numIdentityPackets = 0;
@@ -60,6 +62,7 @@ public:
         processIncomingPacketsElapsedTime += rhs.processIncomingPacketsElapsedTime;
 
         nodesBroadcastedTo += rhs.nodesBroadcastedTo;
+        downstreamMixersBroadcastedTo += rhs.downstreamMixersBroadcastedTo;
         numPacketsSent += rhs.numPacketsSent;
         numBytesSent += rhs.numBytesSent;
         numIdentityPackets += rhs.numIdentityPackets;
@@ -92,6 +95,10 @@ public:
 
 private:
     int sendIdentityPacket(const AvatarMixerClientData* nodeData, const SharedNodePointer& destinationNode);
+    int sendReplicatedIdentityPacket(const AvatarMixerClientData* nodeData, const SharedNodePointer& destinationNode);
+
+    void broadcastAvatarDataToAgent(const SharedNodePointer& node);
+    void broadcastAvatarDataToDownstreamMixer(const SharedNodePointer& node);
 
     // frame state
     ConstIter _begin;
diff --git a/assignment-client/src/avatars/AvatarMixerSlavePool.cpp b/assignment-client/src/avatars/AvatarMixerSlavePool.cpp
index 07d4fa8851..cb5ae7735a 100644
--- a/assignment-client/src/avatars/AvatarMixerSlavePool.cpp
+++ b/assignment-client/src/avatars/AvatarMixerSlavePool.cpp
@@ -76,8 +76,8 @@ void AvatarMixerSlavePool::processIncomingPackets(ConstIter begin, ConstIter end
 }
 
 void AvatarMixerSlavePool::broadcastAvatarData(ConstIter begin, ConstIter end, 
-                                     p_high_resolution_clock::time_point lastFrameTimestamp, 
-                                     float maxKbpsPerNode, float throttlingRatio) {
+                                               p_high_resolution_clock::time_point lastFrameTimestamp,
+                                               float maxKbpsPerNode, float throttlingRatio) {
     _function = &AvatarMixerSlave::broadcastAvatarData;
     _configure = [&](AvatarMixerSlave& slave) { 
         slave.configureBroadcast(begin, end, lastFrameTimestamp, maxKbpsPerNode, throttlingRatio);
diff --git a/domain-server/resources/describe-settings.json b/domain-server/resources/describe-settings.json
index 817333bb72..fd0e107558 100644
--- a/domain-server/resources/describe-settings.json
+++ b/domain-server/resources/describe-settings.json
@@ -1335,6 +1335,66 @@
           "advanced": true
         }
       ]
+    },
+    {
+      "name": "broadcasting",
+      "label": "Broadcasting",
+      "settings": [
+        {
+          "name": "users",
+          "label": "Broadcasted Users",
+          "type": "table",
+          "can_add_new_rows": true,
+          "help": "Users that are broadcasted to downstream servers",
+          "numbered": false,
+          "columns": [
+            {
+              "name": "user",
+              "label": "User",
+              "can_set": true
+            }
+          ]
+        },
+        {
+          "name": "downstream_servers",
+          "label": "Receiving Servers",
+          "assignment-types": [0,1],
+          "type": "table",
+          "can_add_new_rows": true,
+          "help": "Servers that receive data for broadcasted users",
+          "numbered": false,
+          "columns": [
+            {
+              "name": "address",
+              "label": "Address",
+              "can_set": true
+            },
+            {
+              "name": "port",
+              "label": "Port",
+              "can_set": true
+            },
+            {
+              "name": "server_type",
+              "label": "Server Type",
+              "type": "select",
+              "placeholder": "Audio Mixer",
+              "default": "Audio Mixer",
+              "can_set": true,
+              "options": [
+                {
+                  "value": "Audio Mixer",
+                  "label": "Audio Mixer"
+                },
+                {
+                  "value": "Avatar Mixer",
+                  "label": "Avatar Mixer"
+                }
+              ]
+            }
+          ]
+        }
+      ]
     }
   ]
 }
diff --git a/domain-server/resources/web/settings/js/settings.js b/domain-server/resources/web/settings/js/settings.js
index 0057df721a..ccd36da757 100644
--- a/domain-server/resources/web/settings/js/settings.js
+++ b/domain-server/resources/web/settings/js/settings.js
@@ -39,7 +39,8 @@ var Settings = {
   ACCESS_TOKEN_SELECTOR: '[name="metaverse.access_token"]',
   PLACES_TABLE_ID: 'places-table',
   FORM_ID: 'settings-form',
-  INVALID_ROW_CLASS: 'invalid-input'
+  INVALID_ROW_CLASS: 'invalid-input',
+  DATA_ROW_INDEX: 'data-row-index'
 };
 
 var viewHelpers = {
@@ -223,10 +224,10 @@ $(document).ready(function(){
             // set focus to the first input in the new row
             $target.closest('table').find('tr.inputs input:first').focus();
           }
-          
+
           var tableRows = sibling.parent();
           var tableBody = tableRows.parent();
-          
+
           // if theres no more siblings, we should jump to a new row
           if (sibling.next().length == 0 && tableRows.nextAll().length == 1) {
               tableBody.find("." + Settings.ADD_ROW_BUTTON_CLASS).click();
@@ -1005,7 +1006,7 @@ function saveSettings() {
       var password = formJSON["security"]["http_password"];
       var verify_password = formJSON["security"]["verify_http_password"];
 
-      // if they've only emptied out the default password field, we should go ahead and acknowledge 
+      // if they've only emptied out the default password field, we should go ahead and acknowledge
       // the verify password field
       if (password != undefined && verify_password == undefined) {
         verify_password = "";
@@ -1158,8 +1159,9 @@ function makeTable(setting, keypath, setting_value) {
       }
 
       html += "<tr class='" + Settings.DATA_ROW_CLASS + "' " +
-                   (isCategorized ? ("data-category='" + categoryValue + "'") : "") + " " +
-                   (isArray ? "" : "name='" + keypath + "." + rowIndexOrName + "'") + ">";
+        (isCategorized ? ("data-category='" + categoryValue + "'") : "") + " " +
+        (isArray ? "" : "name='" + keypath + "." + rowIndexOrName + "'") +
+        (isArray ? Settings.DATA_ROW_INDEX + "='" + (row_num - 1) + "'" : "" ) + ">";
 
       if (setting.numbered === true) {
         html += "<td class='numbered'>" + row_num + "</td>"
@@ -1289,6 +1291,17 @@ function makeTableHiddenInputs(setting, initialValues, categoryValue) {
           "<input type='checkbox' style='display: none;' class='form-control table-checkbox' " +
                  "name='" + col.name + "'" + (defaultValue ? " checked" : "") + "/>" +
         "</td>";
+    } else if (col.type === "select") {
+        html += "<td class='" + Settings.DATA_COL_CLASS + "'name='" + col.name + "'>"
+        html += "<select style='display: none;' class='form-control' data-hidden-input='" + col.name + "'>'"
+
+        for (var i in col.options) {
+            var option = col.options[i];
+            html += "<option value='" + option.value + "' " + (option.value == defaultValue ? 'selected' : '') + ">" + option.label + "</option>";
+        }
+
+        html += "</select>";
+        html += "<input type='hidden' class='table-dropdown form-control trigger-change' name='" + col.name + "' value='" +  defaultValue + "'></td>";
     } else {
       html +=
         "<td " + (col.hidden ? "style='display: none;'" : "") + " class='" + Settings.DATA_COL_CLASS + "' " +
@@ -1411,6 +1424,21 @@ function addTableRow(row) {
   var setting_name = table.attr("name");
   row.addClass(Settings.DATA_ROW_CLASS + " " + Settings.NEW_ROW_CLASS);
 
+  // if this is an array, add the row index (which is the index of the last row + 1)
+  // as a data attribute to the row
+  var row_index = 0;
+  if (isArray) {
+    var previous_row = row.siblings('.' + Settings.DATA_ROW_CLASS + ':last');
+
+    if (previous_row.length > 0) {
+      row_index = parseInt(previous_row.attr(Settings.DATA_ROW_INDEX), 10) + 1;
+    } else {
+      row_index = 0;
+    }
+
+    row.attr(Settings.DATA_ROW_INDEX, row_index);
+  }
+
   var focusChanged = false;
 
   _.each(row.children(), function(element) {
@@ -1440,19 +1468,23 @@ function addTableRow(row) {
       input.show();
 
       var isCheckbox = input.hasClass("table-checkbox");
+      var isDropdown = input.hasClass("table-dropdown");
 
       if (isArray) {
-        var row_index = row.siblings('.' + Settings.DATA_ROW_CLASS).length
         var key = $(element).attr('name');
 
         // are there multiple columns or just one?
         // with multiple we have an array of Objects, with one we have an array of whatever the value type is
         var num_columns = row.children('.' + Settings.DATA_COL_CLASS).length
+        var newName = setting_name + "[" + row_index + "]" + (num_columns > 1 ? "." + key : "");
 
-        if (isCheckbox) {
-          input.attr("name", setting_name + "[" + row_index + "]" + (num_columns > 1 ? "." + key : ""))
-        } else {
-          input.attr("name", setting_name + "[" + row_index + "]" + (num_columns > 1 ? "." + key : ""))
+        input.attr("name", newName);
+
+        if (isDropdown) {
+          // default values for hidden inputs inside child selects gets cleared so we need to remind it
+          var selectElement = $(element).children("select");
+          selectElement.attr("data-hidden-input", newName);
+          $(element).children("input").val(selectElement.val());
         }
       } else {
         // because the name of the setting in question requires the key
@@ -1468,6 +1500,12 @@ function addTableRow(row) {
           focusChanged = true;
       }
 
+      // if we are adding a dropdown, we should go ahead and make its select
+      // element is visible
+      if (isDropdown) {
+          $(element).children("select").attr("style", "");
+      }
+
       if (isCheckbox) {
         $(input).find("input").attr("data-changed", "true");
       } else {
diff --git a/domain-server/src/DomainServer.cpp b/domain-server/src/DomainServer.cpp
index 0c1ebbf189..7c14d2e924 100644
--- a/domain-server/src/DomainServer.cpp
+++ b/domain-server/src/DomainServer.cpp
@@ -117,6 +117,10 @@ DomainServer::DomainServer(int argc, char* argv[]) :
     // if permissions are updated, relay the changes to the Node datastructures
     connect(&_settingsManager, &DomainServerSettingsManager::updateNodePermissions,
             &_gatekeeper, &DomainGatekeeper::updateNodePermissions);
+    connect(&_settingsManager, &DomainServerSettingsManager::settingsUpdated,
+            this, &DomainServer::updateReplicatedNodes);
+    connect(&_settingsManager, &DomainServerSettingsManager::settingsUpdated,
+            this, &DomainServer::updateDownstreamNodes);
 
     setupGroupCacheRefresh();
 
@@ -129,6 +133,9 @@ DomainServer::DomainServer(int argc, char* argv[]) :
 
     setupNodeListAndAssignments();
 
+    updateReplicatedNodes();
+    updateDownstreamNodes();
+
     if (_type != NonMetaverse) {
         // if we have a metaverse domain, we'll use an access token for API calls
         resetAccountManagerAccessToken();
@@ -958,6 +965,11 @@ void DomainServer::handleConnectedNode(SharedNodePointer newNode) {
         emit userConnected();
     }
 
+    if (shouldReplicateNode(*newNode)) {
+        qDebug() << "Setting node to replicated: " << newNode->getUUID();
+        newNode->setIsReplicated(true);
+    }
+
     // send out this node to our other connected nodes
     broadcastNewNode(newNode);
 }
@@ -2215,6 +2227,131 @@ void DomainServer::refreshStaticAssignmentAndAddToQueue(SharedAssignmentPointer&
     _unfulfilledAssignments.enqueue(assignment);
 }
 
+static const QString BROADCASTING_SETTINGS_KEY = "broadcasting";
+
+void DomainServer::updateDownstreamNodes() {
+    auto settings = _settingsManager.getSettingsMap();
+    if (settings.contains(BROADCASTING_SETTINGS_KEY)) {
+        auto nodeList = DependencyManager::get<LimitedNodeList>();
+        std::vector<HifiSockAddr> downstreamNodesInSettings;
+        auto replicationSettings = settings.value(BROADCASTING_SETTINGS_KEY).toMap();
+        if (replicationSettings.contains("downstream_servers")) {
+            auto serversSettings = replicationSettings.value("downstream_servers").toList();
+
+            std::vector<HifiSockAddr> knownDownstreamNodes;
+            nodeList->eachNode([&](const SharedNodePointer& otherNode) {
+                if (NodeType::isDownstream(otherNode->getType())) {
+                    knownDownstreamNodes.push_back(otherNode->getPublicSocket());
+                }
+            });
+
+            for (auto& server : serversSettings) {
+                auto downstreamServer = server.toMap();
+
+                static const QString DOWNSTREAM_SERVER_ADDRESS = "address";
+                static const QString DOWNSTREAM_SERVER_PORT = "port";
+                static const QString DOWNSTREAM_SERVER_TYPE = "server_type";
+
+                // make sure we have the settings we need for this downstream server
+                if (downstreamServer.contains(DOWNSTREAM_SERVER_ADDRESS) && downstreamServer.contains(DOWNSTREAM_SERVER_PORT)) {
+
+                    auto nodeType = NodeType::fromString(downstreamServer[DOWNSTREAM_SERVER_TYPE].toString());
+                    auto downstreamNodeType = NodeType::downstreamType(nodeType);
+
+                    // read the address and port and construct a HifiSockAddr from them
+                    HifiSockAddr downstreamServerAddr {
+                        downstreamServer[DOWNSTREAM_SERVER_ADDRESS].toString(),
+                        (quint16) downstreamServer[DOWNSTREAM_SERVER_PORT].toString().toInt()
+                    };
+                    downstreamNodesInSettings.push_back(downstreamServerAddr);
+
+                    bool knownNode = find(knownDownstreamNodes.cbegin(), knownDownstreamNodes.cend(),
+                                          downstreamServerAddr) != knownDownstreamNodes.cend();
+                    if (!knownNode) {
+                        // manually add the downstream node to our node list
+                        auto node = nodeList->addOrUpdateNode(QUuid::createUuid(), downstreamNodeType,
+                                                              downstreamServerAddr, downstreamServerAddr);
+                        node->setIsForcedNeverSilent(true);
+
+                        qDebug() << "Adding downstream node:" << node->getUUID() << downstreamServerAddr;
+
+                        // manually activate the public socket for the downstream node
+                        node->activatePublicSocket();
+                    }
+                }
+
+            }
+        }
+
+        // enumerate the nodes to determine which are no longer downstream for this domain
+        // collect them in a vector to separately remove them with handleKillNode (since eachNode has a read lock and
+        // we cannot recursively take the write lock required by handleKillNode)
+        std::vector<SharedNodePointer> nodesToKill;
+        nodeList->eachNode([&](const SharedNodePointer& otherNode) {
+            if (NodeType::isDownstream(otherNode->getType())) {
+                bool nodeInSettings = find(downstreamNodesInSettings.cbegin(), downstreamNodesInSettings.cend(),
+                                           otherNode->getPublicSocket()) != downstreamNodesInSettings.cend();
+                if (!nodeInSettings) {
+                    qDebug() << "Removing downstream node:" << otherNode->getUUID() << otherNode->getPublicSocket();
+                    nodesToKill.push_back(otherNode);
+                }
+            }
+        });
+
+        for (auto& node : nodesToKill) {
+            handleKillNode(node);
+        }
+    }
+}
+
+void DomainServer::updateReplicatedNodes() {
+    // Make sure we have downstream nodes in our list
+    auto settings = _settingsManager.getSettingsMap();
+
+    static const QString REPLICATED_USERS_KEY = "users";
+    _replicatedUsernames.clear();
+    
+    if (settings.contains(BROADCASTING_SETTINGS_KEY)) {
+        auto replicationSettings = settings.value(BROADCASTING_SETTINGS_KEY).toMap();
+        if (replicationSettings.contains(REPLICATED_USERS_KEY)) {
+            auto usersSettings = replicationSettings.value(REPLICATED_USERS_KEY).toList();
+            for (auto& username : usersSettings) {
+                _replicatedUsernames.push_back(username.toString().toLower());
+            }
+        }
+    }
+
+    auto nodeList = DependencyManager::get<LimitedNodeList>();
+    nodeList->eachMatchingNode([this](const SharedNodePointer& otherNode) -> bool {
+            return otherNode->getType() == NodeType::Agent;
+        }, [this](const SharedNodePointer& otherNode) {
+            auto shouldReplicate = shouldReplicateNode(*otherNode);
+            auto isReplicated = otherNode->isReplicated();
+            if (isReplicated && !shouldReplicate) {
+                qDebug() << "Setting node to NOT be replicated:"
+                    << otherNode->getPermissions().getVerifiedUserName() << otherNode->getUUID();
+            } else if (!isReplicated && shouldReplicate) {
+                qDebug() << "Setting node to replicated:"
+                    << otherNode->getPermissions().getVerifiedUserName() << otherNode->getUUID();
+            }
+            otherNode->setIsReplicated(shouldReplicate);
+        }
+    );
+}
+
+bool DomainServer::shouldReplicateNode(const Node& node) {
+    if (node.getType() == NodeType::Agent) {
+        QString verifiedUsername = node.getPermissions().getVerifiedUserName();
+
+        // Both the verified username and usernames in _replicatedUsernames are lowercase, so
+        // comparisons here are case-insensitive.
+        auto it = find(_replicatedUsernames.cbegin(), _replicatedUsernames.cend(), verifiedUsername);
+        return it != _replicatedUsernames.end();
+    } else {
+        return false;
+    }
+};
+
 void DomainServer::nodeAdded(SharedNodePointer node) {
     // we don't use updateNodeWithData, so add the DomainServerNodeData to the node here
     node->setLinkedData(std::unique_ptr<DomainServerNodeData> { new DomainServerNodeData() });
diff --git a/domain-server/src/DomainServer.h b/domain-server/src/DomainServer.h
index 63b82cb37d..7e43397e9c 100644
--- a/domain-server/src/DomainServer.h
+++ b/domain-server/src/DomainServer.h
@@ -102,6 +102,9 @@ private slots:
 
     void handleOctreeFileReplacement(QByteArray octreeFile);
 
+    void updateReplicatedNodes();
+    void updateDownstreamNodes();
+
 signals:
     void iceServerChanged();
     void userConnected();
@@ -161,12 +164,16 @@ private:
     QJsonObject jsonForSocket(const HifiSockAddr& socket);
     QJsonObject jsonObjectForNode(const SharedNodePointer& node);
 
+    bool shouldReplicateNode(const Node& node);
+
     void setupGroupCacheRefresh();
 
     QString pathForRedirect(QString path = QString()) const;
 
     SubnetList _acSubnetWhitelist;
 
+    std::vector<QString> _replicatedUsernames;
+
     DomainGatekeeper _gatekeeper;
 
     HTTPManager _httpManager;
diff --git a/domain-server/src/DomainServerSettingsManager.cpp b/domain-server/src/DomainServerSettingsManager.cpp
index d6b57b450a..9279648319 100644
--- a/domain-server/src/DomainServerSettingsManager.cpp
+++ b/domain-server/src/DomainServerSettingsManager.cpp
@@ -991,6 +991,7 @@ bool DomainServerSettingsManager::handleAuthenticatedHTTPRequest(HTTPConnection
             unpackPermissions();
             apiRefreshGroupInformation();
             emit updateNodePermissions();
+            emit settingsUpdated();
         }
 
         return true;
@@ -1196,13 +1197,14 @@ QJsonObject DomainServerSettingsManager::settingDescriptionFromGroup(const QJson
 bool DomainServerSettingsManager::recurseJSONObjectAndOverwriteSettings(const QJsonObject& postedObject) {
     static const QString SECURITY_ROOT_KEY = "security";
     static const QString AC_SUBNET_WHITELIST_KEY = "ac_subnet_whitelist";
+    static const QString BROADCASTING_KEY = "broadcasting";
 
     auto& settingsVariant = _configMap.getConfig();
     bool needRestart = false;
 
     // Iterate on the setting groups
     foreach(const QString& rootKey, postedObject.keys()) {
-        QJsonValue rootValue = postedObject[rootKey];
+        const QJsonValue& rootValue = postedObject[rootKey];
 
         if (!settingsVariant.contains(rootKey)) {
             // we don't have a map below this key yet, so set it up now
@@ -1247,7 +1249,7 @@ bool DomainServerSettingsManager::recurseJSONObjectAndOverwriteSettings(const QJ
 
             if (!matchingDescriptionObject.isEmpty()) {
                 updateSetting(rootKey, rootValue, *thisMap, matchingDescriptionObject);
-                if (rootKey != SECURITY_ROOT_KEY) {
+                if (rootKey != SECURITY_ROOT_KEY && rootKey != BROADCASTING_KEY) {
                     needRestart = true;
                 }
             } else {
@@ -1261,9 +1263,10 @@ bool DomainServerSettingsManager::recurseJSONObjectAndOverwriteSettings(const QJ
 
                 // if we matched the setting then update the value
                 if (!matchingDescriptionObject.isEmpty()) {
-                    QJsonValue settingValue = rootValue.toObject()[settingKey];
+                    const QJsonValue& settingValue = rootValue.toObject()[settingKey];
                     updateSetting(settingKey, settingValue, *thisMap, matchingDescriptionObject);
-                    if (rootKey != SECURITY_ROOT_KEY || settingKey == AC_SUBNET_WHITELIST_KEY) {
+                    if ((rootKey != SECURITY_ROOT_KEY && rootKey != BROADCASTING_KEY)
+                        || settingKey == AC_SUBNET_WHITELIST_KEY) {
                         needRestart = true;
                     }
                 } else {
diff --git a/domain-server/src/DomainServerSettingsManager.h b/domain-server/src/DomainServerSettingsManager.h
index d56a786d4b..4c7d8dfbc9 100644
--- a/domain-server/src/DomainServerSettingsManager.h
+++ b/domain-server/src/DomainServerSettingsManager.h
@@ -108,6 +108,7 @@ public:
 
 signals:
     void updateNodePermissions();
+    void settingsUpdated();
 
 public slots:
     void apiGetGroupIDJSONCallback(QNetworkReply& requestReply);
diff --git a/libraries/audio/src/InboundAudioStream.cpp b/libraries/audio/src/InboundAudioStream.cpp
index 88ec7e7bc0..da8997895c 100644
--- a/libraries/audio/src/InboundAudioStream.cpp
+++ b/libraries/audio/src/InboundAudioStream.cpp
@@ -127,6 +127,7 @@ int InboundAudioStream::parseData(ReceivedMessage& message) {
     // parse the info after the seq number and before the audio data (the stream properties)
     int prePropertyPosition = message.getPosition();
     int propertyBytes = parseStreamProperties(message.getType(), message.readWithoutCopy(message.getBytesLeftToRead()), networkFrames);
+
     message.seek(prePropertyPosition + propertyBytes);
 
     // handle this packet based on its arrival status.
@@ -147,7 +148,8 @@ int InboundAudioStream::parseData(ReceivedMessage& message) {
         }
         case SequenceNumberStats::OnTime: {
             // Packet is on time; parse its data to the ringbuffer
-            if (message.getType() == PacketType::SilentAudioFrame) {
+            if (message.getType() == PacketType::SilentAudioFrame
+                || message.getType() == PacketType::ReplicatedSilentAudioFrame) {
                 // If we recieved a SilentAudioFrame from our sender, we might want to drop
                 // some of the samples in order to catch up to our desired jitter buffer size.
                 writeDroppableSilentFrames(networkFrames);
@@ -168,7 +170,10 @@ int InboundAudioStream::parseData(ReceivedMessage& message) {
 
                     // inform others of the mismatch
                     auto sendingNode = DependencyManager::get<NodeList>()->nodeWithUUID(message.getSourceID());
-                    emit mismatchedAudioCodec(sendingNode, _selectedCodecName, codecInPacket);
+                    if (sendingNode) {
+                        emit mismatchedAudioCodec(sendingNode, _selectedCodecName, codecInPacket);
+                    }
+
                 }
             }
             break;
diff --git a/libraries/avatars/src/AvatarData.cpp b/libraries/avatars/src/AvatarData.cpp
index 7731d53ec3..eb4a02cb62 100644
--- a/libraries/avatars/src/AvatarData.cpp
+++ b/libraries/avatars/src/AvatarData.cpp
@@ -1473,27 +1473,6 @@ QStringList AvatarData::getJointNames() const {
     return _jointNames;
 }
 
-void AvatarData::parseAvatarIdentityPacket(const QByteArray& data, Identity& identityOut) {
-    QDataStream packetStream(data);
-
-    packetStream >> identityOut.uuid
-                 >> identityOut.skeletonModelURL
-                 >> identityOut.attachmentData
-                 >> identityOut.displayName
-                 >> identityOut.sessionDisplayName
-                 >> identityOut.avatarEntityData
-                 >> identityOut.sequenceId;
-
-#ifdef WANT_DEBUG
-    qCDebug(avatars) << __FUNCTION__
-        << "identityOut.uuid:" << identityOut.uuid
-        << "identityOut.skeletonModelURL:" << identityOut.skeletonModelURL
-        << "identityOut.displayName:" << identityOut.displayName
-        << "identityOut.sessionDisplayName:" << identityOut.sessionDisplayName;
-#endif
-
-}
-
 glm::quat AvatarData::getOrientationOutbound() const {
     return (getLocalOrientation());
 }
@@ -1504,47 +1483,82 @@ QUrl AvatarData::cannonicalSkeletonModelURL(const QUrl& emptyURL) const {
     return _skeletonModelURL.scheme() == "file" ? emptyURL : _skeletonModelURL;
 }
 
-void AvatarData::processAvatarIdentity(const Identity& identity, bool& identityChanged, bool& displayNameChanged, bool& skeletonModelUrlChanged) {
+void AvatarData::processAvatarIdentity(const QByteArray& identityData, bool& identityChanged,
+                                       bool& displayNameChanged, bool& skeletonModelUrlChanged) {
 
-    if (identity.sequenceId < _identitySequenceId) {
-        qCDebug(avatars) << "Ignoring older identity packet for avatar" << getSessionUUID()
-            << "_identitySequenceId (" << _identitySequenceId << ") is greater than" << identity.sequenceId;
-        return;
+    QDataStream packetStream(identityData);
+
+    QUuid avatarSessionID;
+
+    // peek the sequence number, this will tell us if we should be processing this identity packet at all
+    udt::SequenceNumber::Type incomingSequenceNumberType;
+    packetStream >> avatarSessionID >> incomingSequenceNumberType;
+    udt::SequenceNumber incomingSequenceNumber(incomingSequenceNumberType);
+
+    if (!_hasProcessedFirstIdentity) {
+        _lastSequenceNumber = incomingSequenceNumber - 1;
+        _hasProcessedFirstIdentity = true;
+        qCDebug(avatars) << "Processing first identity packet for" << avatarSessionID << "-"
+            << (udt::SequenceNumber::Type) incomingSequenceNumber;
     }
-    // otherwise, set the identitySequenceId to match the incoming identity
-    _identitySequenceId = identity.sequenceId;
 
-    if (_firstSkeletonCheck || (identity.skeletonModelURL != cannonicalSkeletonModelURL(emptyURL))) {
-        setSkeletonModelURL(identity.skeletonModelURL);
-        identityChanged = true;
-        skeletonModelUrlChanged = true;
-        if (_firstSkeletonCheck) {
+    if (incomingSequenceNumber > _lastSequenceNumber) {
+        Identity identity;
+
+        packetStream >> identity.skeletonModelURL
+            >> identity.attachmentData
+            >> identity.displayName
+            >> identity.sessionDisplayName
+            >> identity.avatarEntityData;
+
+        // set the store identity sequence number to match the incoming identity
+        _lastSequenceNumber = incomingSequenceNumber;
+
+        if (_firstSkeletonCheck || (identity.skeletonModelURL != cannonicalSkeletonModelURL(emptyURL))) {
+            setSkeletonModelURL(identity.skeletonModelURL);
+            identityChanged = true;
+            skeletonModelUrlChanged = true;
+            if (_firstSkeletonCheck) {
+                displayNameChanged = true;
+            }
+            _firstSkeletonCheck = false;
+        }
+
+        if (identity.displayName != _displayName) {
+            _displayName = identity.displayName;
+            identityChanged = true;
             displayNameChanged = true;
         }
-        _firstSkeletonCheck = false;
-    }
+        maybeUpdateSessionDisplayNameFromTransport(identity.sessionDisplayName);
 
-    if (identity.displayName != _displayName) {
-        _displayName = identity.displayName;
-        identityChanged = true;
-        displayNameChanged = true;
-    }
-    maybeUpdateSessionDisplayNameFromTransport(identity.sessionDisplayName);
+        if (identity.attachmentData != _attachmentData) {
+            setAttachmentData(identity.attachmentData);
+            identityChanged = true;
+        }
 
-    if (identity.attachmentData != _attachmentData) {
-        setAttachmentData(identity.attachmentData);
-        identityChanged = true;
-    }
+        bool avatarEntityDataChanged = false;
+        _avatarEntitiesLock.withReadLock([&] {
+            avatarEntityDataChanged = (identity.avatarEntityData != _avatarEntityData);
+        });
+        
+        if (avatarEntityDataChanged) {
+            setAvatarEntityData(identity.avatarEntityData);
+            identityChanged = true;
+        }
 
-    bool avatarEntityDataChanged = false;
-    _avatarEntitiesLock.withReadLock([&] {
-        avatarEntityDataChanged = (identity.avatarEntityData != _avatarEntityData);
-    });
-    if (avatarEntityDataChanged) {
-        setAvatarEntityData(identity.avatarEntityData);
-        identityChanged = true;
-    }
+#ifdef WANT_DEBUG
+        qCDebug(avatars) << __FUNCTION__
+            << "identity.uuid:" << identity.uuid
+            << "identity.skeletonModelURL:" << identity.skeletonModelURL
+            << "identity.displayName:" << identity.displayName
+            << "identity.sessionDisplayName:" << identity.sessionDisplayName;
+    } else {
 
+        qCDebug(avatars) << "Refusing to process identity for" << uuidStringWithoutCurlyBraces(avatarSessionID) << "since"
+            << (udt::SequenceNumber::Type) _lastSequenceNumber
+            << "is >=" << (udt::SequenceNumber::Type) incomingSequenceNumber;
+#endif
+    }
 }
 
 QByteArray AvatarData::identityByteArray() const {
@@ -1552,14 +1566,17 @@ QByteArray AvatarData::identityByteArray() const {
     QDataStream identityStream(&identityData, QIODevice::Append);
     const QUrl& urlToSend = cannonicalSkeletonModelURL(emptyURL); // depends on _skeletonModelURL
 
+    // when mixers send identity packets to agents, they simply forward along the last incoming sequence number they received
+    // whereas agents send a fresh outgoing sequence number when identity data has changed
+
     _avatarEntitiesLock.withReadLock([&] {
         identityStream << getSessionUUID()
-                       << urlToSend
-                       << _attachmentData
-                       << _displayName
-                       << getSessionDisplayNameForTransport() // depends on _sessionDisplayName
-                       << _avatarEntityData
-                       << _identitySequenceId;
+            << (udt::SequenceNumber::Type) _lastSequenceNumber
+            << urlToSend
+            << _attachmentData
+            << _displayName
+            << getSessionDisplayNameForTransport() // depends on _sessionDisplayName
+            << _avatarEntityData;
     });
 
     return identityData;
@@ -1735,6 +1752,12 @@ void AvatarData::sendAvatarDataPacket() {
 
 void AvatarData::sendIdentityPacket() {
     auto nodeList = DependencyManager::get<NodeList>();
+
+    if (_identityDataChanged) {
+        // if the identity data has changed, push the sequence number forwards
+        ++_lastSequenceNumber;
+    }
+
     QByteArray identityData = identityByteArray();
 
     auto packetList = NLPacketList::create(PacketType::AvatarIdentity, QByteArray(), true, true);
@@ -1745,7 +1768,7 @@ void AvatarData::sendIdentityPacket() {
         },
         [&](const SharedNodePointer& node) {
             nodeList->sendPacketList(std::move(packetList), *node);
-        });
+    });
 
     _avatarEntityDataLocallyEdited = false;
     _identityDataChanged = false;
diff --git a/libraries/avatars/src/AvatarData.h b/libraries/avatars/src/AvatarData.h
index 8941d9d95f..8d09f936b5 100644
--- a/libraries/avatars/src/AvatarData.h
+++ b/libraries/avatars/src/AvatarData.h
@@ -52,15 +52,16 @@ typedef unsigned long long quint64;
 #include <JointData.h>
 #include <NLPacket.h>
 #include <Node.h>
-#include <RegisteredMetaTypes.h>
-#include <SimpleMovingAverage.h>
-#include <SpatiallyNestable.h>
 #include <NumericalConstants.h>
 #include <Packed.h>
-#include <ThreadSafeValueCache.h>
+#include <RegisteredMetaTypes.h>
 #include <SharedUtil.h>
-#include <shared/RateCounter.h>
+#include <SimpleMovingAverage.h>
+#include <SpatiallyNestable.h>
+#include <ThreadSafeValueCache.h>
 #include <ViewFrustum.h>
+#include <shared/RateCounter.h>
+#include <udt/SequenceNumber.h>
 
 #include "AABox.h"
 #include "HeadData.h"
@@ -526,19 +527,17 @@ public:
     const HeadData* getHeadData() const { return _headData; }
 
     struct Identity {
-        QUuid uuid;
         QUrl skeletonModelURL;
         QVector<AttachmentData> attachmentData;
         QString displayName;
         QString sessionDisplayName;
         AvatarEntityMap avatarEntityData;
-        quint64 sequenceId;
     };
 
-    static void parseAvatarIdentityPacket(const QByteArray& data, Identity& identityOut);
-
+    // identityChanged returns true if identity has changed, false otherwise.
     // identityChanged returns true if identity has changed, false otherwise. Similarly for displayNameChanged and skeletonModelUrlChange.
-    void processAvatarIdentity(const Identity& identity, bool& identityChanged, bool& displayNameChanged, bool& skeletonModelUrlChanged);
+    void processAvatarIdentity(const QByteArray& identityData, bool& identityChanged,
+                               bool& displayNameChanged, bool& skeletonModelUrlChanged);
 
     QByteArray identityByteArray() const;
 
@@ -624,10 +623,7 @@ public:
     static float _avatarSortCoefficientAge;
 
     bool getIdentityDataChanged() const { return _identityDataChanged; } // has the identity data changed since the last time sendIdentityPacket() was called
-    void markIdentityDataChanged() {
-        _identityDataChanged = true;
-        _identitySequenceId++;
-    }
+    void markIdentityDataChanged() { _identityDataChanged = true; }
 
     float getDensity() const { return _density; }
 
@@ -785,7 +781,8 @@ protected:
     float _audioAverageLoudness { 0.0f };
 
     bool _identityDataChanged { false };
-    quint64 _identitySequenceId { 0 };
+    udt::SequenceNumber _lastSequenceNumber { 0 };
+    bool _hasProcessedFirstIdentity { false };
     float _density;
 
 private:
diff --git a/libraries/avatars/src/AvatarHashMap.cpp b/libraries/avatars/src/AvatarHashMap.cpp
index fb954f4731..e8c37bdaa8 100644
--- a/libraries/avatars/src/AvatarHashMap.cpp
+++ b/libraries/avatars/src/AvatarHashMap.cpp
@@ -126,8 +126,14 @@ AvatarSharedPointer AvatarHashMap::parseAvatarData(QSharedPointer<ReceivedMessag
 }
 
 void AvatarHashMap::processAvatarIdentityPacket(QSharedPointer<ReceivedMessage> message, SharedNodePointer sendingNode) {
-    AvatarData::Identity identity;
-    AvatarData::parseAvatarIdentityPacket(message->getMessage(), identity);
+
+    // peek the avatar UUID from the incoming packet
+    QUuid identityUUID = QUuid::fromRfc4122(message->peek(NUM_BYTES_RFC4122_UUID));
+
+    if (identityUUID.isNull()) {
+        qCDebug(avatars) << "Refusing to process identity packet for null avatar ID";
+        return;
+    }
 
     // make sure this isn't for an ignored avatar
     auto nodeList = DependencyManager::get<NodeList>();
@@ -136,21 +142,22 @@ void AvatarHashMap::processAvatarIdentityPacket(QSharedPointer<ReceivedMessage>
     {
         QReadLocker locker(&_hashLock);
         auto me = _avatarHash.find(EMPTY);
-        if ((me != _avatarHash.end()) && (identity.uuid == me.value()->getSessionUUID())) {
+        if ((me != _avatarHash.end()) && (identityUUID == me.value()->getSessionUUID())) {
             // We add MyAvatar to _avatarHash with an empty UUID. Code relies on this. In order to correctly handle an
             // identity packet for ourself (such as when we are assigned a sessionDisplayName by the mixer upon joining),
             // we make things match here.
-            identity.uuid = EMPTY;
+            identityUUID = EMPTY;
         }
     }
-    if (!nodeList->isIgnoringNode(identity.uuid) || nodeList->getRequestsDomainListData()) {
+    
+    if (!nodeList->isIgnoringNode(identityUUID) || nodeList->getRequestsDomainListData()) {
         // mesh URL for a UUID, find avatar in our list
-        auto avatar = newOrExistingAvatar(identity.uuid, sendingNode);
+        auto avatar = newOrExistingAvatar(identityUUID, sendingNode);
         bool identityChanged = false;
         bool displayNameChanged = false;
         bool skeletonModelUrlChanged = false;
         // In this case, the "sendingNode" is the Avatar Mixer.
-        avatar->processAvatarIdentity(identity, identityChanged, displayNameChanged, skeletonModelUrlChanged);
+        avatar->processAvatarIdentity(message->getMessage(), identityChanged, displayNameChanged, skeletonModelUrlChanged);
     }
 }
 
diff --git a/libraries/networking/src/LimitedNodeList.cpp b/libraries/networking/src/LimitedNodeList.cpp
index f9baff0daf..d2bae28820 100644
--- a/libraries/networking/src/LimitedNodeList.cpp
+++ b/libraries/networking/src/LimitedNodeList.cpp
@@ -446,7 +446,8 @@ qint64 LimitedNodeList::sendPacketList(std::unique_ptr<NLPacketList> packetList,
 
         return _nodeSocket.writePacketList(std::move(packetList), *activeSocket);
     } else {
-        qCDebug(networking) << "LimitedNodeList::sendPacketList called without active socket for node. Not sending.";
+        qCDebug(networking) << "LimitedNodeList::sendPacketList called without active socket for node "
+                            << destinationNode.getUUID() << ". Not sending.";
         return ERROR_SENDING_PACKET_BYTES;
     }
 }
@@ -454,7 +455,8 @@ qint64 LimitedNodeList::sendPacketList(std::unique_ptr<NLPacketList> packetList,
 qint64 LimitedNodeList::sendPacket(std::unique_ptr<NLPacket> packet, const Node& destinationNode,
                                    const HifiSockAddr& overridenSockAddr) {
     if (overridenSockAddr.isNull() && !destinationNode.getActiveSocket()) {
-        qCDebug(networking) << "LimitedNodeList::sendPacket called without active socket for node. Not sending.";
+        qCDebug(networking) << "LimitedNodeList::sendPacket called without active socket for node"
+                            << destinationNode.getUUID() << ". Not sending.";
         return ERROR_SENDING_PACKET_BYTES;
     }
 
@@ -568,8 +570,8 @@ void LimitedNodeList::handleNodeKill(const SharedNodePointer& node) {
 
 SharedNodePointer LimitedNodeList::addOrUpdateNode(const QUuid& uuid, NodeType_t nodeType,
                                                    const HifiSockAddr& publicSocket, const HifiSockAddr& localSocket,
-                                                   const NodePermissions& permissions,
-                                                   const QUuid& connectionSecret) {
+                                                   bool isReplicated, bool isUpstream,
+                                                   const QUuid& connectionSecret, const NodePermissions& permissions) {
     QReadLocker readLocker(&_nodeMutex);
     NodeHash::const_iterator it = _nodeHash.find(uuid);
 
@@ -580,11 +582,20 @@ SharedNodePointer LimitedNodeList::addOrUpdateNode(const QUuid& uuid, NodeType_t
         matchingNode->setLocalSocket(localSocket);
         matchingNode->setPermissions(permissions);
         matchingNode->setConnectionSecret(connectionSecret);
+        matchingNode->setIsReplicated(isReplicated);
+        matchingNode->setIsUpstream(isUpstream);
 
         return matchingNode;
     } else {
         // we didn't have this node, so add them
-        Node* newNode = new Node(uuid, nodeType, publicSocket, localSocket, permissions, connectionSecret);
+        Node* newNode = new Node(uuid, nodeType, publicSocket, localSocket);
+        newNode->setIsReplicated(isReplicated);
+        newNode->setIsUpstream(isUpstream);
+        newNode->setConnectionSecret(connectionSecret);
+        newNode->setPermissions(permissions);
+
+        // move the newly constructed node to the LNL thread
+        newNode->moveToThread(thread());
 
         if (nodeType == NodeType::AudioMixer) {
             LimitedNodeList::flagTimeForConnectionStep(LimitedNodeList::AddedAudioMixer);
@@ -742,7 +753,8 @@ void LimitedNodeList::removeSilentNodes() {
         SharedNodePointer node = it->second;
         node->getMutex().lock();
 
-        if ((usecTimestampNow() - node->getLastHeardMicrostamp()) > (NODE_SILENCE_THRESHOLD_MSECS * USECS_PER_MSEC)) {
+        if (!node->isForcedNeverSilent()
+            && (usecTimestampNow() - node->getLastHeardMicrostamp()) > (NODE_SILENCE_THRESHOLD_MSECS * USECS_PER_MSEC)) {
             // call the NodeHash erase to get rid of this node
             it = _nodeHash.unsafe_erase(it);
 
diff --git a/libraries/networking/src/LimitedNodeList.h b/libraries/networking/src/LimitedNodeList.h
index 554386f786..ab61c71952 100644
--- a/libraries/networking/src/LimitedNodeList.h
+++ b/libraries/networking/src/LimitedNodeList.h
@@ -145,8 +145,9 @@ public:
 
     SharedNodePointer addOrUpdateNode(const QUuid& uuid, NodeType_t nodeType,
                                       const HifiSockAddr& publicSocket, const HifiSockAddr& localSocket,
-                                      const NodePermissions& permissions = DEFAULT_AGENT_PERMISSIONS,
-                                      const QUuid& connectionSecret = QUuid());
+                                      bool isReplicated = false, bool isUpstream = false,
+                                      const QUuid& connectionSecret = QUuid(),
+                                      const NodePermissions& permissions = DEFAULT_AGENT_PERMISSIONS);
 
     static bool parseSTUNResponse(udt::BasePacket* packet, QHostAddress& newPublicAddress, uint16_t& newPublicPort);
     bool hasCompletedInitialSTUN() const { return _hasCompletedInitialSTUN; }
@@ -257,6 +258,16 @@ public:
         return SharedNodePointer();
     }
 
+    // This is unsafe because it does not take a lock
+    // Must only be called when you know that a read lock on the node mutex is held
+    // and will be held for the duration of your iteration
+    template<typename NodeLambda>
+    void unsafeEachNode(NodeLambda functor) {
+        for (NodeHash::const_iterator it = _nodeHash.cbegin(); it != _nodeHash.cend(); ++it) {
+            functor(it->second);
+        }
+    }
+
     void putLocalPortIntoSharedMemory(const QString key, QObject* parent, quint16 localPort);
     bool getLocalServerPortFromSharedMemory(const QString key, quint16& localPort);
 
@@ -386,6 +397,7 @@ protected:
         }
     }
 
+
 private slots:
     void flagTimeForConnectionStep(ConnectionStep connectionStep, quint64 timestamp);
     void possiblyTimeoutSTUNAddressLookup();
diff --git a/libraries/networking/src/NLPacket.h b/libraries/networking/src/NLPacket.h
index 33de262dfb..f9056bbfaa 100644
--- a/libraries/networking/src/NLPacket.h
+++ b/libraries/networking/src/NLPacket.h
@@ -42,6 +42,7 @@ public:
     
     static std::unique_ptr<NLPacket> fromReceivedPacket(std::unique_ptr<char[]> data, qint64 size,
                                                         const HifiSockAddr& senderSockAddr);
+
     static std::unique_ptr<NLPacket> fromBase(std::unique_ptr<Packet> packet);
     
     // Provided for convenience, try to limit use
diff --git a/libraries/networking/src/NLPacketList.h b/libraries/networking/src/NLPacketList.h
index 48ce5ef81a..910d39f71b 100644
--- a/libraries/networking/src/NLPacketList.h
+++ b/libraries/networking/src/NLPacketList.h
@@ -23,6 +23,8 @@ public:
     
     PacketVersion getVersion() const { return _packetVersion; }
     const QUuid& getSourceID() const { return _sourceID; }
+
+    qint64 getMaxSegmentSize() const override { return NLPacket::maxPayloadSize(_packetType, _isOrdered); }
     
 private:
     NLPacketList(PacketType packetType, QByteArray extendedHeader = QByteArray(), bool isReliable = false,
diff --git a/libraries/networking/src/NetworkPeer.h b/libraries/networking/src/NetworkPeer.h
index 7185ffef29..9842768b37 100644
--- a/libraries/networking/src/NetworkPeer.h
+++ b/libraries/networking/src/NetworkPeer.h
@@ -76,6 +76,14 @@ public:
     float getOutboundBandwidth() const; // in kbps
     float getInboundBandwidth() const; // in kbps
 
+    // Typically the LimitedNodeList removes nodes after they are "silent"
+    // meaning that we have not received any packets (including simple keepalive pings) from them for a set interval.
+    // The _isForcedNeverSilent flag tells the LimitedNodeList that a Node should never be killed by removeSilentNodes()
+    // even if its the timestamp of when it was last heard from has never been updated.
+
+    bool isForcedNeverSilent() const { return _isForcedNeverSilent; }
+    void setIsForcedNeverSilent(bool isForcedNeverSilent) { _isForcedNeverSilent = isForcedNeverSilent; }
+
     friend QDataStream& operator<<(QDataStream& out, const NetworkPeer& peer);
     friend QDataStream& operator>>(QDataStream& in, NetworkPeer& peer);
 public slots:
@@ -103,6 +111,8 @@ protected:
     QTimer* _pingTimer = NULL;
 
     int _connectionAttempts;
+
+    bool _isForcedNeverSilent { false };
 };
 
 QDebug operator<<(QDebug debug, const NetworkPeer &peer);
diff --git a/libraries/networking/src/Node.cpp b/libraries/networking/src/Node.cpp
index 60227eeaa1..ea1b6e0eb5 100644
--- a/libraries/networking/src/Node.cpp
+++ b/libraries/networking/src/Node.cpp
@@ -42,6 +42,8 @@ void NodeType::init() {
     TypeNameHash.insert(NodeType::MessagesMixer, "Messages Mixer");
     TypeNameHash.insert(NodeType::AssetServer, "Asset Server");
     TypeNameHash.insert(NodeType::EntityScriptServer, "Entity Script Server");
+    TypeNameHash.insert(NodeType::DownstreamAudioMixer, "Downstream Audio Mixer");
+    TypeNameHash.insert(NodeType::DownstreamAvatarMixer, "Downstream Avatar Mixer");
     TypeNameHash.insert(NodeType::Unassigned, "Unassigned");
 }
 
@@ -50,17 +52,34 @@ const QString& NodeType::getNodeTypeName(NodeType_t nodeType) {
     return matchedTypeName != TypeNameHash.end() ? matchedTypeName.value() : UNKNOWN_NodeType_t_NAME;
 }
 
+bool NodeType::isDownstream(NodeType_t nodeType) {
+    return nodeType ==  NodeType::DownstreamAudioMixer || nodeType == NodeType::DownstreamAvatarMixer;
+}
+
+NodeType_t NodeType::downstreamType(NodeType_t primaryType) {
+    switch (primaryType) {
+        case AudioMixer:
+            return DownstreamAudioMixer;
+        case AvatarMixer:
+            return DownstreamAvatarMixer;
+        default:
+            return Unassigned;
+    }
+}
+
+NodeType_t NodeType::fromString(QString type) {
+    return TypeNameHash.key(type, NodeType::Unassigned);
+}
+
+
 Node::Node(const QUuid& uuid, NodeType_t type, const HifiSockAddr& publicSocket,
-           const HifiSockAddr& localSocket, const NodePermissions& permissions, const QUuid& connectionSecret,
-           QObject* parent) :
+           const HifiSockAddr& localSocket, QObject* parent) :
     NetworkPeer(uuid, publicSocket, localSocket, parent),
     _type(type),
-    _connectionSecret(connectionSecret),
     _pingMs(-1),  // "Uninitialized"
     _clockSkewUsec(0),
     _mutex(),
-    _clockSkewMovingPercentile(30, 0.8f),   // moving 80th percentile of 30 samples
-    _permissions(permissions)
+    _clockSkewMovingPercentile(30, 0.8f)   // moving 80th percentile of 30 samples
 {
     // Update socket's object name
     setType(_type);
@@ -135,6 +154,7 @@ QDataStream& operator<<(QDataStream& out, const Node& node) {
     out << node._publicSocket;
     out << node._localSocket;
     out << node._permissions;
+    out << node._isReplicated;
     return out;
 }
 
@@ -144,6 +164,7 @@ QDataStream& operator>>(QDataStream& in, Node& node) {
     in >> node._publicSocket;
     in >> node._localSocket;
     in >> node._permissions;
+    in >> node._isReplicated;
     return in;
 }
 
diff --git a/libraries/networking/src/Node.h b/libraries/networking/src/Node.h
index 1bb3a0cdc8..c20ff5a395 100644
--- a/libraries/networking/src/Node.h
+++ b/libraries/networking/src/Node.h
@@ -37,9 +37,9 @@
 class Node : public NetworkPeer {
     Q_OBJECT
 public:
+
     Node(const QUuid& uuid, NodeType_t type,
          const HifiSockAddr& publicSocket, const HifiSockAddr& localSocket,
-         const NodePermissions& permissions, const QUuid& connectionSecret = QUuid(),
          QObject* parent = nullptr);
 
     bool operator==(const Node& otherNode) const { return _uuid == otherNode._uuid; }
@@ -48,6 +48,12 @@ public:
     char getType() const { return _type; }
     void setType(char type);
 
+    bool isReplicated() const { return _isReplicated; }
+    void setIsReplicated(bool isReplicated) { _isReplicated = isReplicated; }
+
+    bool isUpstream() const { return _isUpstream; }
+    void setIsUpstream(bool isUpstream) { _isUpstream = isUpstream; }
+
     const QUuid& getConnectionSecret() const { return _connectionSecret; }
     void setConnectionSecret(const QUuid& connectionSecret) { _connectionSecret = connectionSecret; }
 
@@ -89,13 +95,16 @@ private:
 
     QUuid _connectionSecret;
     std::unique_ptr<NodeData> _linkedData;
+    bool _isReplicated { false };
     int _pingMs;
     qint64 _clockSkewUsec;
     QMutex _mutex;
     MovingPercentile _clockSkewMovingPercentile;
     NodePermissions _permissions;
+    bool _isUpstream { false };
     tbb::concurrent_unordered_set<QUuid, UUIDHasher> _ignoredNodeIDSet;
     mutable QReadWriteLock _ignoredNodeIDSetLock;
+    std::vector<QString> _replicatedUsernames { };
 
     std::atomic_bool _ignoreRadiusEnabled;
 };
diff --git a/libraries/networking/src/NodeList.cpp b/libraries/networking/src/NodeList.cpp
index 2aa30b84aa..f502cb2a3c 100644
--- a/libraries/networking/src/NodeList.cpp
+++ b/libraries/networking/src/NodeList.cpp
@@ -654,8 +654,9 @@ void NodeList::parseNodeFromPacketStream(QDataStream& packetStream) {
     QUuid nodeUUID, connectionUUID;
     HifiSockAddr nodePublicSocket, nodeLocalSocket;
     NodePermissions permissions;
+    bool isReplicated;
 
-    packetStream >> nodeType >> nodeUUID >> nodePublicSocket >> nodeLocalSocket >> permissions;
+    packetStream >> nodeType >> nodeUUID >> nodePublicSocket >> nodeLocalSocket >> permissions >> isReplicated;
 
     // if the public socket address is 0 then it's reachable at the same IP
     // as the domain server
@@ -666,7 +667,12 @@ void NodeList::parseNodeFromPacketStream(QDataStream& packetStream) {
     packetStream >> connectionUUID;
 
     SharedNodePointer node = addOrUpdateNode(nodeUUID, nodeType, nodePublicSocket,
-                                             nodeLocalSocket, permissions, connectionUUID);
+                                             nodeLocalSocket, isReplicated, false, connectionUUID, permissions);
+
+    // nodes that are downstream of our own type are kept alive when we hear about them from the domain server
+    if (node->getType() == NodeType::downstreamType(_ownerType)) {
+        node->setLastHeardMicrostamp(usecTimestampNow());
+    }
 }
 
 void NodeList::sendAssignment(Assignment& assignment) {
@@ -711,14 +717,20 @@ void NodeList::pingPunchForInactiveNode(const SharedNodePointer& node) {
 }
 
 void NodeList::startNodeHolePunch(const SharedNodePointer& node) {
-    // connect to the correct signal on this node so we know when to ping it
-    connect(node.data(), &Node::pingTimerTimeout, this, &NodeList::handleNodePingTimeout);
 
-    // start the ping timer for this node
-    node->startPingTimer();
+    // we don't hole punch to downstream servers, since it is assumed that we have a direct line to them
+    // we also don't hole punch to relayed upstream nodes, since we do not communicate directly with them
 
-    // ping this node immediately
-    pingPunchForInactiveNode(node);
+    if (!NodeType::isDownstream(node->getType()) && !node->isUpstream()) {
+        // connect to the correct signal on this node so we know when to ping it
+        connect(node.data(), &Node::pingTimerTimeout, this, &NodeList::handleNodePingTimeout);
+
+        // start the ping timer for this node
+        node->startPingTimer();
+
+        // ping this node immediately
+        pingPunchForInactiveNode(node);
+    }
 }
 
 void NodeList::handleNodePingTimeout() {
@@ -761,8 +773,11 @@ void NodeList::stopKeepalivePingTimer() {
 }
 
 void NodeList::sendKeepAlivePings() {
+    // send keep-alive ping packets to nodes of types we care about that are not relayed to us from an upstream node
+
     eachMatchingNode([this](const SharedNodePointer& node)->bool {
-        return _nodeTypesOfInterest.contains(node->getType());
+        auto type = node->getType();
+        return !node->isUpstream() && _nodeTypesOfInterest.contains(type) && !NodeType::isDownstream(type);
     }, [&](const SharedNodePointer& node) {
         sendPacket(constructPingPacket(), *node);
     });
@@ -1120,4 +1135,4 @@ void NodeList::setRequestsDomainListData(bool isRequesting) {
 
 void NodeList::startThread() {
     moveToNewNamedThread(this, "NodeList Thread", QThread::TimeCriticalPriority);
-}
\ No newline at end of file
+}
diff --git a/libraries/networking/src/NodeType.h b/libraries/networking/src/NodeType.h
index 5ae7a835b6..dacd5e1a68 100644
--- a/libraries/networking/src/NodeType.h
+++ b/libraries/networking/src/NodeType.h
@@ -25,10 +25,17 @@ namespace NodeType {
     const NodeType_t AssetServer = 'A';
     const NodeType_t MessagesMixer = 'm';
     const NodeType_t EntityScriptServer = 'S';
+    const NodeType_t DownstreamAudioMixer = 'a';
+    const NodeType_t DownstreamAvatarMixer = 'w';
     const NodeType_t Unassigned = 1;
 
     void init();
+
     const QString& getNodeTypeName(NodeType_t nodeType);
+    bool isDownstream(NodeType_t nodeType);
+    NodeType_t downstreamType(NodeType_t primaryType);
+
+    NodeType_t fromString(QString type);
 }
 
 typedef QSet<NodeType_t> NodeSet;
diff --git a/libraries/networking/src/ReceivedMessage.cpp b/libraries/networking/src/ReceivedMessage.cpp
index 2c5a11334b..6ca249fb22 100644
--- a/libraries/networking/src/ReceivedMessage.cpp
+++ b/libraries/networking/src/ReceivedMessage.cpp
@@ -42,6 +42,20 @@ ReceivedMessage::ReceivedMessage(NLPacket& packet)
 {
 }
 
+ReceivedMessage::ReceivedMessage(QByteArray byteArray, PacketType packetType, PacketVersion packetVersion,
+                const HifiSockAddr& senderSockAddr, QUuid sourceID) :
+    _data(byteArray),
+    _headData(_data.mid(0, HEAD_DATA_SIZE)),
+    _numPackets(1),
+    _sourceID(sourceID),
+    _packetType(packetType),
+    _packetVersion(packetVersion),
+    _senderSockAddr(senderSockAddr),
+    _isComplete(true)
+{
+
+}
+
 void ReceivedMessage::setFailed() {
     _failed = true;
     _isComplete = true;
diff --git a/libraries/networking/src/ReceivedMessage.h b/libraries/networking/src/ReceivedMessage.h
index 3acb7163e7..ae51e7592a 100644
--- a/libraries/networking/src/ReceivedMessage.h
+++ b/libraries/networking/src/ReceivedMessage.h
@@ -24,6 +24,8 @@ class ReceivedMessage : public QObject {
 public:
     ReceivedMessage(const NLPacketList& packetList);
     ReceivedMessage(NLPacket& packet);
+    ReceivedMessage(QByteArray byteArray, PacketType packetType, PacketVersion packetVersion,
+                    const HifiSockAddr& senderSockAddr, QUuid sourceID = QUuid());
 
     QByteArray getMessage() const { return _data; }
     const char* getRawMessage() const { return _data.constData(); }
diff --git a/libraries/networking/src/ThreadedAssignment.cpp b/libraries/networking/src/ThreadedAssignment.cpp
index 9db540cae2..18e4593c91 100644
--- a/libraries/networking/src/ThreadedAssignment.cpp
+++ b/libraries/networking/src/ThreadedAssignment.cpp
@@ -10,6 +10,7 @@
 //
 
 #include <QtCore/QCoreApplication>
+#include <QtCore/QJsonArray>
 #include <QtCore/QJsonObject>
 #include <QtCore/QThread>
 #include <QtCore/QTimer>
diff --git a/libraries/networking/src/ThreadedAssignment.h b/libraries/networking/src/ThreadedAssignment.h
index e9832a2a91..8b35acaac5 100644
--- a/libraries/networking/src/ThreadedAssignment.h
+++ b/libraries/networking/src/ThreadedAssignment.h
@@ -18,6 +18,8 @@
 
 #include "Assignment.h"
 
+using DownstreamNodeFoundCallback = std::function<void(Node& downstreamNode)>;
+
 class ThreadedAssignment : public Assignment {
     Q_OBJECT
 public:
@@ -40,6 +42,7 @@ signals:
 
 protected:
     void commonInit(const QString& targetName, NodeType_t nodeType);
+
     bool _isFinished;
     QTimer _domainServerTimer;
     QTimer _statsTimer;
diff --git a/libraries/networking/src/udt/PacketHeaders.cpp b/libraries/networking/src/udt/PacketHeaders.cpp
index d59da2f726..fb416cac4d 100644
--- a/libraries/networking/src/udt/PacketHeaders.cpp
+++ b/libraries/networking/src/udt/PacketHeaders.cpp
@@ -39,7 +39,19 @@ const QSet<PacketType> NON_SOURCED_PACKETS = QSet<PacketType>()
     << PacketType::ICEServerPeerInformation << PacketType::ICEServerQuery << PacketType::ICEServerHeartbeat
     << PacketType::ICEServerHeartbeatACK << PacketType::ICEPing << PacketType::ICEPingReply
     << PacketType::ICEServerHeartbeatDenied << PacketType::AssignmentClientStatus << PacketType::StopNode
-    << PacketType::DomainServerRemovedNode << PacketType::UsernameFromIDReply << PacketType::OctreeFileReplacement;
+    << PacketType::DomainServerRemovedNode << PacketType::UsernameFromIDReply << PacketType::OctreeFileReplacement
+    << PacketType::ReplicatedMicrophoneAudioNoEcho << PacketType::ReplicatedMicrophoneAudioWithEcho
+    << PacketType::ReplicatedInjectAudio << PacketType::ReplicatedSilentAudioFrame
+    << PacketType::ReplicatedAvatarIdentity << PacketType::ReplicatedKillAvatar << PacketType::ReplicatedBulkAvatarData;
+
+const QHash<PacketType, PacketType> REPLICATED_PACKET_MAPPING {
+    { PacketType::MicrophoneAudioNoEcho, PacketType::ReplicatedMicrophoneAudioNoEcho },
+    { PacketType::MicrophoneAudioWithEcho, PacketType::ReplicatedMicrophoneAudioWithEcho },
+    { PacketType::InjectAudio, PacketType::ReplicatedInjectAudio },
+    { PacketType::SilentAudioFrame, PacketType::ReplicatedSilentAudioFrame },
+    { PacketType::AvatarIdentity, PacketType::ReplicatedAvatarIdentity },
+    { PacketType::KillAvatar, PacketType::ReplicatedKillAvatar },
+};
 
 PacketVersion versionForPacketType(PacketType packetType) {
     switch (packetType) {
@@ -56,7 +68,7 @@ PacketVersion versionForPacketType(PacketType packetType) {
         case PacketType::AvatarData:
         case PacketType::BulkAvatarData:
         case PacketType::KillAvatar:
-            return static_cast<PacketVersion>(AvatarMixerPacketVersion::MannequinDefaultAvatar);
+            return static_cast<PacketVersion>(AvatarMixerPacketVersion::AvatarIdentitySequenceFront);
         case PacketType::MessagesData:
             return static_cast<PacketVersion>(MessageDataVersion::TextOrBinaryData);
         case PacketType::ICEServerHeartbeat:
@@ -119,7 +131,7 @@ static void ensureProtocolVersionsSignature() {
     std::call_once(once, [&] {
         QByteArray buffer;
         QDataStream stream(&buffer, QIODevice::WriteOnly);
-        uint8_t numberOfProtocols = static_cast<uint8_t>(PacketType::LAST_PACKET_TYPE) + 1;
+        uint8_t numberOfProtocols = static_cast<uint8_t>(PacketType::NUM_PACKET_TYPE);
         stream << numberOfProtocols;
         for (uint8_t packetType = 0; packetType < numberOfProtocols; packetType++) {
             uint8_t packetTypeVersion = static_cast<uint8_t>(versionForPacketType(static_cast<PacketType>(packetType)));
diff --git a/libraries/networking/src/udt/PacketHeaders.h b/libraries/networking/src/udt/PacketHeaders.h
index fa1151e0a6..2944c1ce93 100644
--- a/libraries/networking/src/udt/PacketHeaders.h
+++ b/libraries/networking/src/udt/PacketHeaders.h
@@ -115,12 +115,21 @@ public:
         AdjustAvatarSorting,
         OctreeFileReplacement,
         CollisionEventChanges,
-        LAST_PACKET_TYPE = CollisionEventChanges
+        ReplicatedMicrophoneAudioNoEcho,
+        ReplicatedMicrophoneAudioWithEcho,
+        ReplicatedInjectAudio,
+        ReplicatedSilentAudioFrame,
+        ReplicatedAvatarIdentity,
+        ReplicatedKillAvatar,
+        ReplicatedBulkAvatarData,
+        NUM_PACKET_TYPE
     };
 };
 
 using PacketType = PacketTypeEnum::Value;
 
+extern const QHash<PacketType, PacketType> REPLICATED_PACKET_MAPPING;
+
 const int NUM_BYTES_MD5_HASH = 16;
 
 typedef char PacketVersion;
@@ -237,7 +246,8 @@ enum class AvatarMixerPacketVersion : PacketVersion {
     StickAndBallDefaultAvatar,
     IdentityPacketsIncludeUpdateTime,
     AvatarIdentitySequenceId,
-    MannequinDefaultAvatar
+    MannequinDefaultAvatar,
+    AvatarIdentitySequenceFront
 };
 
 enum class DomainConnectRequestVersion : PacketVersion {
diff --git a/libraries/networking/src/udt/PacketList.cpp b/libraries/networking/src/udt/PacketList.cpp
index 8651f9eed4..d69ff39197 100644
--- a/libraries/networking/src/udt/PacketList.cpp
+++ b/libraries/networking/src/udt/PacketList.cpp
@@ -36,8 +36,8 @@ std::unique_ptr<PacketList> PacketList::fromReceivedPackets(std::list<std::uniqu
 
 PacketList::PacketList(PacketType packetType, QByteArray extendedHeader, bool isReliable, bool isOrdered) :
     _packetType(packetType),
-    _isReliable(isReliable),
     _isOrdered(isOrdered),
+    _isReliable(isReliable),
     _extendedHeader(extendedHeader)
 {
     Q_ASSERT_X(!(!_isReliable && _isOrdered), "PacketList", "Unreliable ordered PacketLists are not currently supported");
@@ -46,8 +46,8 @@ PacketList::PacketList(PacketType packetType, QByteArray extendedHeader, bool is
 PacketList::PacketList(PacketList&& other) :
     _packetType(other._packetType),
     _packets(std::move(other._packets)),
-    _isReliable(other._isReliable),
     _isOrdered(other._isOrdered),
+    _isReliable(other._isReliable),
     _extendedHeader(std::move(other._extendedHeader))
 {
 }
diff --git a/libraries/networking/src/udt/PacketList.h b/libraries/networking/src/udt/PacketList.h
index 5083d77ec9..ff1860c3d1 100644
--- a/libraries/networking/src/udt/PacketList.h
+++ b/libraries/networking/src/udt/PacketList.h
@@ -49,6 +49,8 @@ public:
     void startSegment();
     void endSegment();
 
+    virtual qint64 getMaxSegmentSize() const { return Packet::maxPayloadSize(_isOrdered); }
+
     HifiSockAddr getSenderSockAddr() const;
     
     void closeCurrentPacket(bool shouldSendEmpty = false);
@@ -74,6 +76,8 @@ protected:
     
     PacketType _packetType;
     std::list<std::unique_ptr<Packet>> _packets;
+
+    bool _isOrdered = false;
     
 private:
     friend class ::LimitedNodeList;
@@ -93,7 +97,6 @@ private:
     
     Packet::MessageNumber _messageNumber;
     bool _isReliable = false;
-    bool _isOrdered = false;
     
     std::unique_ptr<Packet> _currentPacket;
     
diff --git a/libraries/networking/src/udt/SequenceNumber.h b/libraries/networking/src/udt/SequenceNumber.h
index 3abc80bdd8..2c82eccfa3 100644
--- a/libraries/networking/src/udt/SequenceNumber.h
+++ b/libraries/networking/src/udt/SequenceNumber.h
@@ -35,8 +35,8 @@ public:
     explicit SequenceNumber(char* value) { _value = (*reinterpret_cast<int32_t*>(value)) & MAX; }
     explicit SequenceNumber(Type value) { _value = (value <= MAX) ? ((value >= 0) ? value : 0) : MAX; }
     explicit SequenceNumber(UType value) { _value = (value <= MAX) ? value : MAX; }
-    explicit operator Type() { return _value; }
-    explicit operator UType() { return static_cast<UType>(_value); }
+    explicit operator Type() const { return _value; }
+    explicit operator UType() const { return static_cast<UType>(_value); }
     
     inline SequenceNumber& operator++() {
         _value = (_value + 1) % (MAX + 1);