diff --git a/assignment-client/src/Agent.cpp b/assignment-client/src/Agent.cpp
index 637bdca67f..0449e0d682 100644
--- a/assignment-client/src/Agent.cpp
+++ b/assignment-client/src/Agent.cpp
@@ -214,7 +214,6 @@ void Agent::run() {
     QNetworkDiskCache* cache = new QNetworkDiskCache();
     QString cachePath = QStandardPaths::writableLocation(QStandardPaths::DataLocation);
     cache->setCacheDirectory(!cachePath.isEmpty() ? cachePath : "agentCache");
-    cache->moveToThread(networkAccessManager.thread());
     networkAccessManager.setCache(cache);
     
     qDebug() << "Downloading script at" << scriptURL.toString();
diff --git a/assignment-client/src/metavoxels/MetavoxelServer.cpp b/assignment-client/src/metavoxels/MetavoxelServer.cpp
index d0c0d4c781..c601478f70 100644
--- a/assignment-client/src/metavoxels/MetavoxelServer.cpp
+++ b/assignment-client/src/metavoxels/MetavoxelServer.cpp
@@ -21,7 +21,8 @@
 const int SEND_INTERVAL = 50;
 
 MetavoxelServer::MetavoxelServer(const QByteArray& packet) :
-    ThreadedAssignment(packet) {
+    ThreadedAssignment(packet),
+    _sendTimer(this) {
     
     _sendTimer.setSingleShot(true);
     connect(&_sendTimer, SIGNAL(timeout()), SLOT(sendDeltas()));
@@ -91,24 +92,54 @@ void MetavoxelServer::sendDeltas() {
 
 MetavoxelSession::MetavoxelSession(const SharedNodePointer& node, MetavoxelServer* server) :
     Endpoint(node, new PacketRecord(), NULL),
-    _server(server) {
+    _server(server),
+    _reliableDeltaChannel(NULL) {
     
     connect(&_sequencer, SIGNAL(receivedHighPriorityMessage(const QVariant&)), SLOT(handleMessage(const QVariant&)));
-    connect(_sequencer.getReliableInputChannel(), SIGNAL(receivedMessage(const QVariant&)),
-        SLOT(handleMessage(const QVariant&)));
+    connect(&_sequencer, SIGNAL(sendAcknowledged(int)), SLOT(checkReliableDeltaReceived()));
+    connect(_sequencer.getReliableInputChannel(), SIGNAL(receivedMessage(const QVariant&, Bitstream&)),
+        SLOT(handleMessage(const QVariant&, Bitstream&)));
 }
 
 void MetavoxelSession::update() {
-    // wait until we have a valid lod
-    if (_lod.isValid()) {
-        Endpoint::update();
+    // wait until we have a valid lod before sending
+    if (!_lod.isValid()) {
+        return;
     }
-}
-
-void MetavoxelSession::writeUpdateMessage(Bitstream& out) {
+    // if we're sending a reliable delta, wait until it's acknowledged
+    if (_reliableDeltaChannel) {
+        Bitstream& out = _sequencer.startPacket();
+        out << QVariant::fromValue(MetavoxelDeltaPendingMessage());
+        _sequencer.endPacket();
+        return;
+    }
+    Bitstream& out = _sequencer.startPacket();
+    int start = _sequencer.getOutputStream().getUnderlying().device()->pos(); 
     out << QVariant::fromValue(MetavoxelDeltaMessage());
     PacketRecord* sendRecord = getLastAcknowledgedSendRecord();
     _server->getData().writeDelta(sendRecord->getData(), sendRecord->getLOD(), out, _lod);
+    out.flush();
+    int end = _sequencer.getOutputStream().getUnderlying().device()->pos();
+    if (end > _sequencer.getMaxPacketSize()) {
+        // we need to send the delta on the reliable channel
+        _reliableDeltaChannel = _sequencer.getReliableOutputChannel(RELIABLE_DELTA_CHANNEL_INDEX);
+        _reliableDeltaChannel->startMessage();
+        _reliableDeltaChannel->getBuffer().write(_sequencer.getOutgoingPacketData().constData() + start, end - start);
+        _reliableDeltaChannel->endMessage();
+        
+        _reliableDeltaWriteMappings = out.getAndResetWriteMappings();
+        _reliableDeltaReceivedOffset = _reliableDeltaChannel->getBytesWritten();
+        _reliableDeltaData = _server->getData();
+        _reliableDeltaLOD = _lod;
+        
+        // go back to the beginning with the current packet and note that there's a delta pending
+        _sequencer.getOutputStream().getUnderlying().device()->seek(start);
+        out << QVariant::fromValue(MetavoxelDeltaPendingMessage());
+        _sequencer.endPacket();
+        
+    } else {
+        _sequencer.endPacket();
+    }
 }
 
 void MetavoxelSession::handleMessage(const QVariant& message, Bitstream& in) {
@@ -116,7 +147,8 @@ void MetavoxelSession::handleMessage(const QVariant& message, Bitstream& in) {
 }
 
 PacketRecord* MetavoxelSession::maybeCreateSendRecord() const {
-    return new PacketRecord(_lod, _server->getData());
+    return _reliableDeltaChannel ? new PacketRecord(_reliableDeltaLOD, _reliableDeltaData) :
+        new PacketRecord(_lod, _server->getData());
 }
 
 void MetavoxelSession::handleMessage(const QVariant& message) {
@@ -134,3 +166,13 @@ void MetavoxelSession::handleMessage(const QVariant& message) {
         }
     }
 }
+
+void MetavoxelSession::checkReliableDeltaReceived() {
+    if (!_reliableDeltaChannel || _reliableDeltaChannel->getOffset() < _reliableDeltaReceivedOffset) {
+        return;
+    }
+    _sequencer.getOutputStream().persistWriteMappings(_reliableDeltaWriteMappings);
+    _reliableDeltaWriteMappings = Bitstream::WriteMappings();
+    _reliableDeltaData = MetavoxelData();
+    _reliableDeltaChannel = NULL;
+}
diff --git a/assignment-client/src/metavoxels/MetavoxelServer.h b/assignment-client/src/metavoxels/MetavoxelServer.h
index d9b010e282..f2769f26f2 100644
--- a/assignment-client/src/metavoxels/MetavoxelServer.h
+++ b/assignment-client/src/metavoxels/MetavoxelServer.h
@@ -63,7 +63,6 @@ public:
 
 protected:
 
-    virtual void writeUpdateMessage(Bitstream& out);
     virtual void handleMessage(const QVariant& message, Bitstream& in);
     
     virtual PacketRecord* maybeCreateSendRecord() const;
@@ -71,12 +70,19 @@ protected:
 private slots:
 
     void handleMessage(const QVariant& message);
+    void checkReliableDeltaReceived();
     
 private:
     
     MetavoxelServer* _server;
     
     MetavoxelLOD _lod;
+    
+    ReliableChannel* _reliableDeltaChannel;
+    int _reliableDeltaReceivedOffset;
+    MetavoxelData _reliableDeltaData;
+    MetavoxelLOD _reliableDeltaLOD;
+    Bitstream::WriteMappings _reliableDeltaWriteMappings;
 };
 
 #endif // hifi_MetavoxelServer_h
diff --git a/examples/locationsMenu.js b/examples/locationsMenu.js
index 6f4a28fe38..24b0dabf46 100644
--- a/examples/locationsMenu.js
+++ b/examples/locationsMenu.js
@@ -57,7 +57,7 @@ var LocationMenu = function(opts) {
         y: 0,
         width: menuWidth + 10,
         height: (menuHeight * (pageSize + 1)) + 10,
-        color: { red: 0, green: 0, blue: 0},
+        backgroundColor: { red: 0, green: 0, blue: 0},
         topMargin: 4,
         leftMargin: 4,
         text: "",
@@ -71,7 +71,7 @@ var LocationMenu = function(opts) {
             y: 0,
             width: menuWidth,
             height: menuHeight,
-            color: inactiveColor,
+            backgroundColor: inactiveColor,
             topMargin: margin,
             leftMargin: margin,
             text: (i == 0) ? "Loading..." : "",
@@ -85,7 +85,7 @@ var LocationMenu = function(opts) {
         y: 0,
         width: menuWidth / 2,
         height: menuHeight,
-        color: disabledColor,
+        backgroundColor: disabledColor,
         topMargin: margin,
         leftMargin: margin,
         text: "Previous",
@@ -97,7 +97,7 @@ var LocationMenu = function(opts) {
         y: 0,
         width: menuWidth / 2,
         height: menuHeight,
-        color: disabledColor,
+        backgroundColor: disabledColor,
         topMargin: margin,
         leftMargin: margin,
         text: "Next",
@@ -175,10 +175,10 @@ var LocationMenu = function(opts) {
             if (start + i < this.locations.length) {
                 location = this.locations[start + i];
                 update.text = (start + i + 1) + ". " + location.username;
-                update.color = inactiveColor;
+                update.backgroundColor = inactiveColor;
             } else {
                 update.text = "";
-                update.color = disabledColor;
+                update.backgroundColor = disabledColor;
             }
             Overlays.editOverlay(this.menuItems[i].overlay, update);
             this.menuItems[i].location = location;
@@ -187,8 +187,8 @@ var LocationMenu = function(opts) {
         this.previousEnabled = pageNumber > 0;
         this.nextEnabled = pageNumber < (this.numPages - 1);
 
-        Overlays.editOverlay(this.previousButton, { color: this.previousEnabled ? prevNextColor : disabledColor});
-        Overlays.editOverlay(this.nextButton, { color: this.nextEnabled ? prevNextColor : disabledColor });
+        Overlays.editOverlay(this.previousButton, { backgroundColor: this.previousEnabled ? prevNextColor : disabledColor});
+        Overlays.editOverlay(this.nextButton, { backgroundColor: this.nextEnabled ? prevNextColor : disabledColor });
     }
 
     this.mousePressEvent = function(event) {
@@ -198,17 +198,17 @@ var LocationMenu = function(opts) {
             self.toggleMenu();
         } else if (clickedOverlay == self.previousButton) {
             if (self.previousEnabled) {
-                Overlays.editOverlay(clickedOverlay, { color: activeColor });
+                Overlays.editOverlay(clickedOverlay, { backgroundColor: activeColor });
             }
         } else if (clickedOverlay == self.nextButton) {
             if (self.nextEnabled) {
-                Overlays.editOverlay(clickedOverlay, { color: activeColor });
+                Overlays.editOverlay(clickedOverlay, { backgroundColor: activeColor });
             }
         } else {
             for (var i = 0; i < self.menuItems.length; i++) {
                 if (clickedOverlay == self.menuItems[i].overlay) {
                     if (self.menuItems[i].location != null) {
-                        Overlays.editOverlay(clickedOverlay, { color: activeColor });
+                        Overlays.editOverlay(clickedOverlay, { backgroundColor: activeColor });
                     }
                     break;
                 }
@@ -221,19 +221,19 @@ var LocationMenu = function(opts) {
 
         if (clickedOverlay == self.previousButton) {
             if (self.previousEnabled) {
-                Overlays.editOverlay(clickedOverlay, { color: inactiveColor });
+                Overlays.editOverlay(clickedOverlay, { backgroundColor: inactiveColor });
                 self.goToPage(self.page - 1);
             }
         } else if (clickedOverlay == self.nextButton) {
             if (self.nextEnabled) {
-                Overlays.editOverlay(clickedOverlay, { color: inactiveColor });
+                Overlays.editOverlay(clickedOverlay, { backgroundColor: inactiveColor });
                 self.goToPage(self.page + 1);
             }
         } else {
             for (var i = 0; i < self.menuItems.length; i++) {
                 if (clickedOverlay == self.menuItems[i].overlay) {
                     if (self.menuItems[i].location != null) {
-                        Overlays.editOverlay(clickedOverlay, { color: inactiveColor });
+                        Overlays.editOverlay(clickedOverlay, { backgroundColor: inactiveColor });
                         var location = self.menuItems[i].location;
                         Window.location = "hifi://" + location.domain + "/"
                                           + location.x + "," + location.y + "," + location.z;
diff --git a/interface/src/Application.cpp b/interface/src/Application.cpp
index c263b71238..ace265ad4f 100644
--- a/interface/src/Application.cpp
+++ b/interface/src/Application.cpp
@@ -316,12 +316,7 @@ Application::Application(int& argc, char** argv, QElapsedTimer &startup_time) :
     QString cachePath = QStandardPaths::writableLocation(QStandardPaths::DataLocation);
 
     NetworkAccessManager& networkAccessManager = NetworkAccessManager::getInstance();
-    
-    // Make sure cache on same thread than its parent (NetworkAccessManager)
     QNetworkDiskCache* cache = new QNetworkDiskCache();
-    cache->moveToThread(networkAccessManager.thread());
-    cache->setParent(&networkAccessManager);
-    
     cache->setCacheDirectory(!cachePath.isEmpty() ? cachePath : "interfaceCache");
     networkAccessManager.setCache(cache);
 
diff --git a/interface/src/Menu.cpp b/interface/src/Menu.cpp
index dba5feca9e..6b32eb5770 100644
--- a/interface/src/Menu.cpp
+++ b/interface/src/Menu.cpp
@@ -1006,7 +1006,6 @@ void Menu::goToDomainDialog() {
     domainDialog.setWindowTitle("Go to Domain");
     domainDialog.setLabelText("Domain server:");
     domainDialog.setTextValue(currentDomainHostname);
-    domainDialog.setWindowFlags(Qt::Sheet);
     domainDialog.resize(domainDialog.parentWidget()->size().width() * DIALOG_RATIO_OF_WINDOW, domainDialog.size().height());
 
     int dialogReturn = domainDialog.exec();
@@ -1044,7 +1043,6 @@ void Menu::goTo() {
     QString destination = QString();
 
     gotoDialog.setTextValue(destination);
-    gotoDialog.setWindowFlags(Qt::Sheet);
     gotoDialog.resize(gotoDialog.parentWidget()->size().width() * DIALOG_RATIO_OF_WINDOW, gotoDialog.size().height());
 
     int dialogReturn = gotoDialog.exec();
@@ -1160,7 +1158,6 @@ void Menu::goToLocation() {
     coordinateDialog.setWindowTitle("Go to Location");
     coordinateDialog.setLabelText("Coordinate as x,y,z:");
     coordinateDialog.setTextValue(currentLocation);
-    coordinateDialog.setWindowFlags(Qt::Sheet);
     coordinateDialog.resize(coordinateDialog.parentWidget()->size().width() * 0.30, coordinateDialog.size().height());
 
     int dialogReturn = coordinateDialog.exec();
@@ -1225,7 +1222,6 @@ void Menu::nameLocation() {
                             "(wherever you are standing and looking now) as you.\n\n"
                             "Location name:");
 
-    nameDialog.setWindowFlags(Qt::Sheet);
     nameDialog.resize((int) (nameDialog.parentWidget()->size().width() * 0.30), nameDialog.size().height());
 
     if (nameDialog.exec() == QDialog::Accepted) {
diff --git a/interface/src/ui/overlays/Overlay.cpp b/interface/src/ui/overlays/Overlay.cpp
index 8ec7cbace1..bc7096c471 100644
--- a/interface/src/ui/overlays/Overlay.cpp
+++ b/interface/src/ui/overlays/Overlay.cpp
@@ -22,7 +22,7 @@
 Overlay::Overlay() :
     _parent(NULL),
     _alpha(DEFAULT_ALPHA),
-    _color(DEFAULT_BACKGROUND_COLOR),
+    _color(DEFAULT_OVERLAY_COLOR),
     _visible(true),
     _anchor(NO_ANCHOR)
 {
diff --git a/interface/src/ui/overlays/Overlay.h b/interface/src/ui/overlays/Overlay.h
index 7667b3d3fd..f8d6400bf6 100644
--- a/interface/src/ui/overlays/Overlay.h
+++ b/interface/src/ui/overlays/Overlay.h
@@ -21,7 +21,7 @@
 
 #include <SharedUtil.h> // for xColor
 
-const xColor DEFAULT_BACKGROUND_COLOR = { 255, 255, 255 };
+const xColor DEFAULT_OVERLAY_COLOR = { 255, 255, 255 };
 const float DEFAULT_ALPHA = 0.7f;
 
 class Overlay : public QObject {
diff --git a/interface/src/ui/overlays/TextOverlay.cpp b/interface/src/ui/overlays/TextOverlay.cpp
index 797d0be1a2..691179ec54 100644
--- a/interface/src/ui/overlays/TextOverlay.cpp
+++ b/interface/src/ui/overlays/TextOverlay.cpp
@@ -18,6 +18,7 @@
 #include "ui/TextRenderer.h"
 
 TextOverlay::TextOverlay() :
+    _backgroundColor(DEFAULT_BACKGROUND_COLOR),
     _leftMargin(DEFAULT_MARGIN),
     _topMargin(DEFAULT_MARGIN),
     _fontSize(DEFAULT_FONTSIZE)
@@ -33,7 +34,7 @@ void TextOverlay::render() {
     }
 
     const float MAX_COLOR = 255;
-    glColor4f(0 / MAX_COLOR, 0 / MAX_COLOR, 0 / MAX_COLOR, _alpha);
+    glColor4f(_backgroundColor.red / MAX_COLOR, _backgroundColor.green / MAX_COLOR, _backgroundColor.blue / MAX_COLOR, _alpha);
 
     glBegin(GL_QUADS);
         glVertex2f(_bounds.left(), _bounds.top());
@@ -82,6 +83,18 @@ void TextOverlay::setProperties(const QScriptValue& properties) {
         setText(text.toVariant().toString());
     }
 
+    QScriptValue backgroundColor = properties.property("backgroundColor");
+    if (backgroundColor.isValid()) {
+        QScriptValue red = backgroundColor.property("red");
+        QScriptValue green = backgroundColor.property("green");
+        QScriptValue blue = backgroundColor.property("blue");
+        if (red.isValid() && green.isValid() && blue.isValid()) {
+            _backgroundColor.red = red.toVariant().toInt();
+            _backgroundColor.green = green.toVariant().toInt();
+            _backgroundColor.blue = blue.toVariant().toInt();
+        }
+    }
+
     if (properties.property("leftMargin").isValid()) {
         setLeftMargin(properties.property("leftMargin").toVariant().toInt());
     }
diff --git a/interface/src/ui/overlays/TextOverlay.h b/interface/src/ui/overlays/TextOverlay.h
index c2aafb24e8..78a51179a0 100644
--- a/interface/src/ui/overlays/TextOverlay.h
+++ b/interface/src/ui/overlays/TextOverlay.h
@@ -27,6 +27,7 @@
 #include "Overlay.h"
 #include "Overlay2D.h"
 
+const xColor DEFAULT_BACKGROUND_COLOR = { 0, 0, 0 };
 const int DEFAULT_MARGIN = 10;
 const int DEFAULT_FONTSIZE = 11;
 
@@ -54,6 +55,7 @@ public:
 private:
 
     QString _text;
+    xColor _backgroundColor;
     int _leftMargin;
     int _topMargin;
     int _fontSize;
diff --git a/libraries/metavoxels/src/Bitstream.cpp b/libraries/metavoxels/src/Bitstream.cpp
index d18903f923..bc662aa890 100644
--- a/libraries/metavoxels/src/Bitstream.cpp
+++ b/libraries/metavoxels/src/Bitstream.cpp
@@ -274,6 +274,26 @@ void Bitstream::persistAndResetReadMappings() {
     persistReadMappings(getAndResetReadMappings());
 }
 
+void Bitstream::copyPersistentMappings(const Bitstream& other) {
+    _objectStreamerStreamer.copyPersistentMappings(other._objectStreamerStreamer);
+    _typeStreamerStreamer.copyPersistentMappings(other._typeStreamerStreamer);
+    _attributeStreamer.copyPersistentMappings(other._attributeStreamer);
+    _scriptStringStreamer.copyPersistentMappings(other._scriptStringStreamer);
+    _sharedObjectStreamer.copyPersistentMappings(other._sharedObjectStreamer);
+    _sharedObjectReferences = other._sharedObjectReferences;
+    _weakSharedObjectHash = other._weakSharedObjectHash;
+}
+
+void Bitstream::clearPersistentMappings() {
+    _objectStreamerStreamer.clearPersistentMappings();
+    _typeStreamerStreamer.clearPersistentMappings();
+    _attributeStreamer.clearPersistentMappings();
+    _scriptStringStreamer.clearPersistentMappings();
+    _sharedObjectStreamer.clearPersistentMappings();
+    _sharedObjectReferences.clear();
+    _weakSharedObjectHash.clear();
+}
+
 void Bitstream::clearSharedObject(int id) {
     SharedObjectPointer object = _sharedObjectStreamer.takePersistentValue(id);
     if (object) {
@@ -1122,7 +1142,7 @@ Bitstream& Bitstream::operator>(ObjectStreamerPointer& streamer) {
     }
     if (_metadataType == NO_METADATA) {
         if (!metaObject) {
-            qWarning() << "Unknown class name:" << className;
+            throw BitstreamException(QString("Unknown class name: ") + className);
         }
         return *this;
     }
@@ -1232,7 +1252,7 @@ Bitstream& Bitstream::operator>(TypeStreamerPointer& streamer) {
     }
     if (_metadataType == NO_METADATA) {
         if (!baseStreamer) {
-            qWarning() << "Unknown type name:" << typeName;
+            throw BitstreamException(QString("Unknown type name: ") + typeName);
         }
         return *this;
     }
@@ -1240,7 +1260,7 @@ Bitstream& Bitstream::operator>(TypeStreamerPointer& streamer) {
     *this >> category;
     if (category == TypeStreamer::SIMPLE_CATEGORY) {
         if (!streamer) {
-            qWarning() << "Unknown type name:" << typeName;
+            throw BitstreamException(QString("Unknown type name: ") + typeName);
         }
         return *this;
     }
@@ -1441,7 +1461,7 @@ Bitstream& Bitstream::operator>(SharedObjectPointer& object) {
         _objectStreamerStreamer >> objectStreamer;
         if (delta) {
             if (!reference) {
-                qWarning() << "Delta without reference" << id << originID;
+                throw BitstreamException(QString("Delta without reference [id=%1, originID=%2]").arg(id).arg(originID));
             }
             objectStreamer->readRawDelta(*this, reference.data(), pointer.data());
         } else {
@@ -1451,7 +1471,7 @@ Bitstream& Bitstream::operator>(SharedObjectPointer& object) {
         QObject* rawObject; 
         if (delta) {
             if (!reference) {
-                qWarning() << "Delta without reference" << id << originID;
+                throw BitstreamException(QString("Delta without reference [id=%1, originID=%2]").arg(id).arg(originID));
             }
             readRawDelta(rawObject, (const QObject*)reference.data());
         } else {
@@ -1682,6 +1702,10 @@ const TypeStreamer* Bitstream::createInvalidTypeStreamer() {
     return streamer;
 }
 
+BitstreamException::BitstreamException(const QString& description) :
+    _description(description) {
+}
+
 QJsonValue JSONWriter::getData(bool value) {
     return value;
 }
diff --git a/libraries/metavoxels/src/Bitstream.h b/libraries/metavoxels/src/Bitstream.h
index e32f93dbe2..70fde94b79 100644
--- a/libraries/metavoxels/src/Bitstream.h
+++ b/libraries/metavoxels/src/Bitstream.h
@@ -102,6 +102,9 @@ public:
     
     V takePersistentValue(int id) { V value = _persistentValues.take(id); _valueIDs.remove(value); return value; }
     
+    void copyPersistentMappings(const RepeatedValueStreamer& other);
+    void clearPersistentMappings();
+    
     RepeatedValueStreamer& operator<<(K value);
     RepeatedValueStreamer& operator>>(V& value);
     
@@ -199,6 +202,29 @@ template<class K, class P, class V> inline RepeatedValueStreamer<K, P, V>&
     return *this;
 }
 
+template<class K, class P, class V> inline void RepeatedValueStreamer<K, P, V>::copyPersistentMappings(
+        const RepeatedValueStreamer<K, P, V>& other) {
+    _lastPersistentID = other._lastPersistentID;
+    _idStreamer.setBitsFromValue(_lastPersistentID);
+    _persistentIDs = other._persistentIDs;
+    _transientOffsets.clear();
+    _lastTransientOffset = 0;
+    _persistentValues = other._persistentValues;
+    _transientValues.clear();
+    _valueIDs = other._valueIDs;
+}
+
+template<class K, class P, class V> inline void RepeatedValueStreamer<K, P, V>::clearPersistentMappings() {
+    _lastPersistentID = 0;
+    _idStreamer.setBitsFromValue(_lastPersistentID);
+    _persistentIDs.clear();
+    _transientOffsets.clear();
+    _lastTransientOffset = 0;
+    _persistentValues.clear();
+    _transientValues.clear();
+    _valueIDs.clear();
+}
+
 /// A stream for bit-aligned data.  Through a combination of code generation, reflection, macros, and templates, provides a
 /// serialization mechanism that may be used for both networking and persistent storage.  For unreliable networking, the
 /// class provides a mapping system that resends mappings for ids until they are acknowledged (and thus persisted).  For
@@ -303,6 +329,9 @@ public:
     Bitstream(QDataStream& underlying, MetadataType metadataType = NO_METADATA,
         GenericsMode = NO_GENERICS, QObject* parent = NULL);
 
+    /// Returns a reference to the underlying data stream.
+    QDataStream& getUnderlying() { return _underlying; }
+
     /// Substitutes the supplied metaobject for the given class name's default mapping.  This is mostly useful for testing the
     /// process of mapping between different types, but may in the future be used for permanently renaming classes.
     void addMetaObjectSubstitution(const QByteArray& className, const QMetaObject* metaObject);
@@ -347,6 +376,12 @@ public:
     /// Immediately persists and resets the read mappings.
     void persistAndResetReadMappings();
 
+    /// Copies the persistent mappings from the specified other stream.
+    void copyPersistentMappings(const Bitstream& other);
+
+    /// Clears the persistent mappings for this stream.
+    void clearPersistentMappings();
+
     /// Returns a reference to the weak hash storing shared objects for this stream.
     const WeakSharedObjectHash& getWeakSharedObjectHash() const { return _weakSharedObjectHash; }
 
@@ -823,6 +858,19 @@ template<class K, class V> inline Bitstream& Bitstream::operator>>(QHash<K, V>&
     return *this;
 }
 
+/// Thrown for unrecoverable errors.
+class BitstreamException {
+public:
+    
+    BitstreamException(const QString& description);
+
+    const QString& getDescription() const { return _description; }
+
+private:
+    
+    QString _description;
+};
+
 /// Provides a means of writing Bitstream-able data to JSON rather than the usual binary format in a manner that allows it to
 /// be manipulated and re-read, converted to binary, etc.  To use, create a JSONWriter, stream values in using the << operator,
 /// and call getDocument to obtain the JSON data.
diff --git a/libraries/metavoxels/src/DatagramSequencer.cpp b/libraries/metavoxels/src/DatagramSequencer.cpp
index eb02497321..2c594fc1ca 100644
--- a/libraries/metavoxels/src/DatagramSequencer.cpp
+++ b/libraries/metavoxels/src/DatagramSequencer.cpp
@@ -113,17 +113,16 @@ Bitstream& DatagramSequencer::startPacket() {
         _outgoingPacketStream << (quint32)record.packetNumber;
     }
     
-    // write the high-priority messages
-    _outgoingPacketStream << (quint32)_highPriorityMessages.size();
-    foreach (const HighPriorityMessage& message, _highPriorityMessages) {
-        _outputStream << message.data;
-    }
-    
     // return the stream, allowing the caller to write the rest
     return _outputStream;
 }
 
 void DatagramSequencer::endPacket() {
+    // write the high-priority messages
+    _outputStream << _highPriorityMessages.size();
+    foreach (const HighPriorityMessage& message, _highPriorityMessages) {
+        _outputStream << message.data;
+    }
     _outputStream.flush();
     
     // if we have space remaining, send some data from our reliable channels 
@@ -222,22 +221,22 @@ void DatagramSequencer::receivedDatagram(const QByteArray& datagram) {
         _sendRecords.erase(_sendRecords.begin(), it + 1);
     }
     
+    // alert external parties so that they can read the middle
+    emit readyToRead(_inputStream);
+    
     // read and dispatch the high-priority messages
-    quint32 highPriorityMessageCount;
-    _incomingPacketStream >> highPriorityMessageCount;
+    int highPriorityMessageCount;
+    _inputStream >> highPriorityMessageCount;
     int newHighPriorityMessages = highPriorityMessageCount - _receivedHighPriorityMessages;
-    for (quint32 i = 0; i < highPriorityMessageCount; i++) {
+    for (int i = 0; i < highPriorityMessageCount; i++) {
         QVariant data;
         _inputStream >> data;
-        if ((int)i >= _receivedHighPriorityMessages) {
+        if (i >= _receivedHighPriorityMessages) {
             emit receivedHighPriorityMessage(data);
         }
     }
     _receivedHighPriorityMessages = highPriorityMessageCount;
     
-    // alert external parties so that they can read the middle
-    emit readyToRead(_inputStream);
-    
     // read the reliable data, if any
     quint32 reliableChannels;
     _incomingPacketStream >> reliableChannels;
@@ -253,6 +252,8 @@ void DatagramSequencer::receivedDatagram(const QByteArray& datagram) {
     // record the receipt
     ReceiveRecord record = { _incomingPacketNumber, _inputStream.getAndResetReadMappings(), newHighPriorityMessages };
     _receiveRecords.append(record);
+    
+    emit receiveRecorded();
 }
 
 void DatagramSequencer::sendClearSharedObjectMessage(int id) {
@@ -274,6 +275,11 @@ void DatagramSequencer::handleHighPriorityMessage(const QVariant& data) {
     }
 }
 
+void DatagramSequencer::clearReliableChannel(QObject* object) {
+    ReliableChannel* channel = static_cast<ReliableChannel*>(object);
+    (channel->isOutput() ? _reliableOutputChannels : _reliableInputChannels).remove(channel->getIndex());
+}
+
 void DatagramSequencer::sendRecordAcknowledged(const SendRecord& record) {
     // stop acknowledging the recorded packets
     while (!_receiveRecords.isEmpty() && _receiveRecords.first().packetNumber <= record.lastReceivedPacketNumber) {
@@ -295,7 +301,10 @@ void DatagramSequencer::sendRecordAcknowledged(const SendRecord& record) {
     
     // acknowledge the received spans
     foreach (const ChannelSpan& span, record.spans) {
-        getReliableOutputChannel(span.channel)->spanAcknowledged(span);
+        ReliableChannel* channel = _reliableOutputChannels.value(span.channel);
+        if (channel) {
+            channel->spanAcknowledged(span);
+        }
     }
     
     // increase the packet rate with every ack until we pass the slow start threshold; then, every round trip
@@ -310,7 +319,10 @@ void DatagramSequencer::sendRecordAcknowledged(const SendRecord& record) {
 void DatagramSequencer::sendRecordLost(const SendRecord& record) {
     // notify the channels of their lost spans
     foreach (const ChannelSpan& span, record.spans) {
-        getReliableOutputChannel(span.channel)->spanLost(record.packetNumber, _outgoingPacketNumber + 1);
+        ReliableChannel* channel = _reliableOutputChannels.value(span.channel);
+        if (channel) {
+            channel->spanLost(record.packetNumber, _outgoingPacketNumber + 1);
+        }
     }
     
     // halve the rate and remember as threshold
@@ -364,6 +376,8 @@ void DatagramSequencer::sendPacket(const QByteArray& packet, const QVector<Chann
         _outputStream.getAndResetWriteMappings(), spans };
     _sendRecords.append(record);
     
+    emit sendRecorded();
+    
     // write the sequence number and size, which are the same between all fragments
     _outgoingDatagramBuffer.seek(_datagramHeaderSize);
     _outgoingDatagramStream << (quint32)_outgoingPacketNumber;
@@ -658,16 +672,24 @@ int ReliableChannel::getBytesAvailable() const {
     return _buffer.size() - _acknowledged.getTotalSet();
 }
 
-void ReliableChannel::sendMessage(const QVariant& message) {
-    // write a placeholder for the length, then fill it in when we know what it is
-    int placeholder = _buffer.pos();
-    _dataStream << (quint32)0;    
-    _bitstream << message;
+void ReliableChannel::startMessage() {
+    // write a placeholder for the length; we'll fill it in when we know what it is
+    _messageLengthPlaceholder = _buffer.pos();
+    _dataStream << (quint32)0;
+}
+
+void ReliableChannel::endMessage() {
     _bitstream.flush();
     _bitstream.persistAndResetWriteMappings();
     
-    quint32 length = _buffer.pos() - placeholder;
-    _buffer.writeBytes(placeholder, sizeof(quint32), (const char*)&length);
+    quint32 length = _buffer.pos() - _messageLengthPlaceholder;
+    _buffer.writeBytes(_messageLengthPlaceholder, sizeof(quint32), (const char*)&length);
+}
+
+void ReliableChannel::sendMessage(const QVariant& message) {
+    startMessage();
+    _bitstream << message;
+    endMessage();
 }
 
 void ReliableChannel::sendClearSharedObjectMessage(int id) {
@@ -675,7 +697,7 @@ void ReliableChannel::sendClearSharedObjectMessage(int id) {
     sendMessage(QVariant::fromValue(message));
 }
 
-void ReliableChannel::handleMessage(const QVariant& message) {
+void ReliableChannel::handleMessage(const QVariant& message, Bitstream& in) {
     if (message.userType() == ClearSharedObjectMessage::Type) {
         _bitstream.clearSharedObject(message.value<ClearSharedObjectMessage>().id);
     
@@ -688,6 +710,7 @@ void ReliableChannel::handleMessage(const QVariant& message) {
 ReliableChannel::ReliableChannel(DatagramSequencer* sequencer, int index, bool output) :
     QObject(sequencer),
     _index(index),
+    _output(output),
     _dataStream(&_buffer),
     _bitstream(_dataStream),
     _priority(1.0f),
@@ -700,7 +723,9 @@ ReliableChannel::ReliableChannel(DatagramSequencer* sequencer, int index, bool o
     _dataStream.setByteOrder(QDataStream::LittleEndian);
     
     connect(&_bitstream, SIGNAL(sharedObjectCleared(int)), SLOT(sendClearSharedObjectMessage(int)));
-    connect(this, SIGNAL(receivedMessage(const QVariant&)), SLOT(handleMessage(const QVariant&)));
+    connect(this, SIGNAL(receivedMessage(const QVariant&, Bitstream&)), SLOT(handleMessage(const QVariant&, Bitstream&)));
+    
+    sequencer->connect(this, SIGNAL(destroyed(QObject*)), SLOT(clearReliableChannel(QObject*)));
 }
 
 void ReliableChannel::writeData(QDataStream& out, int bytes, QVector<DatagramSequencer::ChannelSpan>& spans) {
@@ -843,9 +868,9 @@ void ReliableChannel::readData(QDataStream& in) {
                     _dataStream.skipRawData(sizeof(quint32));
                     QVariant message;
                     _bitstream >> message;
+                    emit receivedMessage(message, _bitstream);
                     _bitstream.reset();
                     _bitstream.persistAndResetReadMappings();
-                    emit receivedMessage(message);
                     continue;
                 }
             }
diff --git a/libraries/metavoxels/src/DatagramSequencer.h b/libraries/metavoxels/src/DatagramSequencer.h
index aa8b6907ff..b85916b561 100644
--- a/libraries/metavoxels/src/DatagramSequencer.h
+++ b/libraries/metavoxels/src/DatagramSequencer.h
@@ -78,6 +78,15 @@ public:
     /// Returns the packet number of the last packet received (or the packet currently being assembled).
     int getIncomingPacketNumber() const { return _incomingPacketNumber; }
     
+    /// Returns a reference to the stream used to read packets.
+    Bitstream& getInputStream() { return _inputStream; }
+    
+    /// Returns a reference to the stream used to write packets.
+    Bitstream& getOutputStream() { return _outputStream; }
+    
+    /// Returns a reference to the outgoing packet data.
+    const QByteArray& getOutgoingPacketData() const { return _outgoingPacketData; }
+    
     /// Returns the packet number of the sent packet at the specified index.
     int getSentPacketNumber(int index) const { return _sendRecords.at(index).packetNumber; }
     
@@ -126,9 +135,15 @@ signals:
     /// Emitted when a packet is available to read.
     void readyToRead(Bitstream& input);
     
-    /// Emitted when we've received a high-priority message
+    /// Emitted when we've received a high-priority message.
     void receivedHighPriorityMessage(const QVariant& data);
     
+    /// Emitted when we've recorded the transmission of a packet.
+    void sendRecorded();
+    
+    /// Emitted when we've recorded the receipt of a packet (that is, at the end of packet processing).
+    void receiveRecorded();
+    
     /// Emitted when a sent packet has been acknowledged by the remote side.
     /// \param index the index of the packet in our list of send records
     void sendAcknowledged(int index);
@@ -141,6 +156,7 @@ private slots:
 
     void sendClearSharedObjectMessage(int id);
     void handleHighPriorityMessage(const QVariant& data);
+    void clearReliableChannel(QObject* object);
     
 private:
     
@@ -319,6 +335,9 @@ public:
     /// Returns the channel's index in the sequencer's channel map.
     int getIndex() const { return _index; }
 
+    /// Checks whether this is an output channel. 
+    bool isOutput() const { return _output; }
+
     /// Returns a reference to the buffer used to write/read data to/from this channel.
     CircularBuffer& getBuffer() { return _buffer; }
     
@@ -336,22 +355,36 @@ public:
     /// Returns the number of bytes available to read from this channel.
     int getBytesAvailable() const;
 
+    /// Returns the offset, which represents the total number of bytes acknowledged
+    /// (on the write end) or received completely (on the read end).
+    int getOffset() const { return _offset; }
+
+    /// Returns the total number of bytes written to this channel.
+    int getBytesWritten() const { return _offset + _buffer.pos(); }
+
     /// Sets whether we expect to write/read framed messages.
     void setMessagesEnabled(bool enabled) { _messagesEnabled = enabled; }
     bool getMessagesEnabled() const { return _messagesEnabled; }
 
-    /// Sends a framed message on this channel.
+    /// Starts a framed message on this channel.
+    void startMessage();
+    
+    /// Ends a framed message on this channel.
+    void endMessage();
+
+    /// Sends a framed message on this channel (convenience function that calls startMessage,
+    /// writes the message to the bitstream, then calls endMessage).
     void sendMessage(const QVariant& message);
 
 signals:
 
     /// Fired when a framed message has been received on this channel.
-    void receivedMessage(const QVariant& message);
+    void receivedMessage(const QVariant& message, Bitstream& in);
 
 private slots:
 
     void sendClearSharedObjectMessage(int id);
-    void handleMessage(const QVariant& message);
+    void handleMessage(const QVariant& message, Bitstream& in);
     
 private:
     
@@ -370,6 +403,7 @@ private:
     void readData(QDataStream& in);
     
     int _index;
+    bool _output;
     CircularBuffer _buffer;
     CircularBuffer _assemblyBuffer;
     QDataStream _dataStream;
@@ -381,6 +415,7 @@ private:
     int _writePositionResetPacketNumber;
     SpanList _acknowledged;
     bool _messagesEnabled;
+    int _messageLengthPlaceholder;
 };
 
 #endif // hifi_DatagramSequencer_h
diff --git a/libraries/metavoxels/src/Endpoint.cpp b/libraries/metavoxels/src/Endpoint.cpp
index c656054504..666ffe52d9 100644
--- a/libraries/metavoxels/src/Endpoint.cpp
+++ b/libraries/metavoxels/src/Endpoint.cpp
@@ -19,6 +19,8 @@ Endpoint::Endpoint(const SharedNodePointer& node, PacketRecord* baselineSendReco
     
     connect(&_sequencer, SIGNAL(readyToWrite(const QByteArray&)), SLOT(sendDatagram(const QByteArray&)));
     connect(&_sequencer, SIGNAL(readyToRead(Bitstream&)), SLOT(readMessage(Bitstream&)));
+    connect(&_sequencer, SIGNAL(sendRecorded()), SLOT(recordSend()));
+    connect(&_sequencer, SIGNAL(receiveRecorded()), SLOT(recordReceive()));
     connect(&_sequencer, SIGNAL(sendAcknowledged(int)), SLOT(clearSendRecordsBefore(int)));
     connect(&_sequencer, SIGNAL(receiveAcknowledged(int)), SLOT(clearReceiveRecordsBefore(int)));
     
@@ -40,9 +42,6 @@ void Endpoint::update() {
     Bitstream& out = _sequencer.startPacket();
     writeUpdateMessage(out);
     _sequencer.endPacket();
-
-    // record the send
-    _sendRecords.append(maybeCreateSendRecord());
 }
 
 int Endpoint::parseData(const QByteArray& packet) {
@@ -59,8 +58,21 @@ void Endpoint::readMessage(Bitstream& in) {
     QVariant message;
     in >> message;
     handleMessage(message, in);
-    
-    // record the receipt
+}
+
+void Endpoint::handleMessage(const QVariant& message, Bitstream& in) {
+    if (message.userType() == QMetaType::QVariantList) {
+        foreach (const QVariant& element, message.toList()) {
+            handleMessage(element, in);
+        }
+    }
+}
+
+void Endpoint::recordSend() {
+    _sendRecords.append(maybeCreateSendRecord());
+}
+
+void Endpoint::recordReceive() {
     _receiveRecords.append(maybeCreateReceiveRecord());
 }
 
@@ -84,14 +96,6 @@ void Endpoint::writeUpdateMessage(Bitstream& out) {
     out << QVariant();
 }
 
-void Endpoint::handleMessage(const QVariant& message, Bitstream& in) {
-    if (message.userType() == QMetaType::QVariantList) {
-        foreach (const QVariant& element, message.toList()) {
-            handleMessage(element, in);
-        }
-    }
-}
-
 PacketRecord* Endpoint::maybeCreateSendRecord() const {
     return NULL;
 }
diff --git a/libraries/metavoxels/src/Endpoint.h b/libraries/metavoxels/src/Endpoint.h
index d253a69ded..3c681a7b98 100644
--- a/libraries/metavoxels/src/Endpoint.h
+++ b/libraries/metavoxels/src/Endpoint.h
@@ -24,6 +24,9 @@ class Endpoint : public NodeData {
     Q_OBJECT
 
 public:
+
+    /// The index of the input/output channel used to transmit reliable deltas.
+    static const int RELIABLE_DELTA_CHANNEL_INDEX = 1;
     
     Endpoint(const SharedNodePointer& node, PacketRecord* baselineSendRecord = NULL,
         PacketRecord* baselineReceiveRecord = NULL);
@@ -37,6 +40,10 @@ protected slots:
 
     virtual void sendDatagram(const QByteArray& data);
     virtual void readMessage(Bitstream& in);
+    virtual void handleMessage(const QVariant& message, Bitstream& in); 
+    
+    void recordSend();
+    void recordReceive();
     
     void clearSendRecordsBefore(int index);
     void clearReceiveRecordsBefore(int index);
@@ -44,7 +51,6 @@ protected slots:
 protected:
 
     virtual void writeUpdateMessage(Bitstream& out);
-    virtual void handleMessage(const QVariant& message, Bitstream& in); 
     
     virtual PacketRecord* maybeCreateSendRecord() const;
     virtual PacketRecord* maybeCreateReceiveRecord() const;
diff --git a/libraries/metavoxels/src/MetavoxelClientManager.cpp b/libraries/metavoxels/src/MetavoxelClientManager.cpp
index 008a477187..e69794917f 100644
--- a/libraries/metavoxels/src/MetavoxelClientManager.cpp
+++ b/libraries/metavoxels/src/MetavoxelClientManager.cpp
@@ -86,7 +86,11 @@ void MetavoxelClientManager::updateClient(MetavoxelClient* client) {
 
 MetavoxelClient::MetavoxelClient(const SharedNodePointer& node, MetavoxelClientManager* manager) :
     Endpoint(node, new PacketRecord(), new PacketRecord()),
-    _manager(manager) {
+    _manager(manager),
+    _reliableDeltaChannel(NULL) {
+    
+    connect(_sequencer.getReliableInputChannel(RELIABLE_DELTA_CHANNEL_INDEX),
+        SIGNAL(receivedMessage(const QVariant&, Bitstream&)), SLOT(handleMessage(const QVariant&, Bitstream&)));
 }
 
 void MetavoxelClient::guide(MetavoxelVisitor& visitor) {
@@ -112,31 +116,44 @@ void MetavoxelClient::writeUpdateMessage(Bitstream& out) {
     out << QVariant::fromValue(state);
 }
 
-void MetavoxelClient::readMessage(Bitstream& in) {
-    Endpoint::readMessage(in);
-    
-    // reapply local edits
-    foreach (const DatagramSequencer::HighPriorityMessage& message, _sequencer.getHighPriorityMessages()) {
-        if (message.data.userType() == MetavoxelEditMessage::Type) {
-            message.data.value<MetavoxelEditMessage>().apply(_data, _sequencer.getWeakSharedObjectHash());
-        }
-    }
-}
-
 void MetavoxelClient::handleMessage(const QVariant& message, Bitstream& in) {
-    if (message.userType() == MetavoxelDeltaMessage::Type) {
+    int userType = message.userType(); 
+    if (userType == MetavoxelDeltaMessage::Type) {
         PacketRecord* receiveRecord = getLastAcknowledgedReceiveRecord();
-        _data.readDelta(receiveRecord->getData(), receiveRecord->getLOD(), in, getLastAcknowledgedSendRecord()->getLOD());
-    
+        if (_reliableDeltaChannel) {    
+            _remoteData.readDelta(receiveRecord->getData(), receiveRecord->getLOD(), in, _remoteDataLOD = _reliableDeltaLOD);
+            _sequencer.getInputStream().persistReadMappings(in.getAndResetReadMappings());
+            in.clearPersistentMappings();
+            _reliableDeltaChannel = NULL;
+        
+        } else {
+            _remoteData.readDelta(receiveRecord->getData(), receiveRecord->getLOD(), in,
+                _remoteDataLOD = getLastAcknowledgedSendRecord()->getLOD());
+            in.reset();
+        }
+        // copy to local and reapply local edits
+        _data = _remoteData;
+        foreach (const DatagramSequencer::HighPriorityMessage& message, _sequencer.getHighPriorityMessages()) {
+            if (message.data.userType() == MetavoxelEditMessage::Type) {
+                message.data.value<MetavoxelEditMessage>().apply(_data, _sequencer.getWeakSharedObjectHash());
+            }
+        }
+    } else if (userType == MetavoxelDeltaPendingMessage::Type) {
+        if (!_reliableDeltaChannel) {
+            _reliableDeltaChannel = _sequencer.getReliableInputChannel(RELIABLE_DELTA_CHANNEL_INDEX);
+            _reliableDeltaChannel->getBitstream().copyPersistentMappings(_sequencer.getInputStream());
+            _reliableDeltaLOD = getLastAcknowledgedSendRecord()->getLOD();
+        }
     } else {
         Endpoint::handleMessage(message, in);
     }
 }
 
 PacketRecord* MetavoxelClient::maybeCreateSendRecord() const {
-    return new PacketRecord(_manager->getLOD());
+    return new PacketRecord(_reliableDeltaChannel ? _reliableDeltaLOD : _manager->getLOD());
 }
 
 PacketRecord* MetavoxelClient::maybeCreateReceiveRecord() const {
-    return new PacketRecord(getLastAcknowledgedSendRecord()->getLOD(), _data);
+    return new PacketRecord(_remoteDataLOD, _remoteData);
 }
+
diff --git a/libraries/metavoxels/src/MetavoxelClientManager.h b/libraries/metavoxels/src/MetavoxelClientManager.h
index dd11e871ec..1f37b15c18 100644
--- a/libraries/metavoxels/src/MetavoxelClientManager.h
+++ b/libraries/metavoxels/src/MetavoxelClientManager.h
@@ -60,7 +60,6 @@ public:
 protected:
 
     virtual void writeUpdateMessage(Bitstream& out);
-    virtual void readMessage(Bitstream& in);
     virtual void handleMessage(const QVariant& message, Bitstream& in);
 
     virtual PacketRecord* maybeCreateSendRecord() const;
@@ -70,6 +69,11 @@ private:
     
     MetavoxelClientManager* _manager;
     MetavoxelData _data;
+    MetavoxelData _remoteData;
+    MetavoxelLOD _remoteDataLOD;
+    
+    ReliableChannel* _reliableDeltaChannel;
+    MetavoxelLOD _reliableDeltaLOD;
 };
 
 #endif // hifi_MetavoxelClientManager_h
diff --git a/libraries/metavoxels/src/MetavoxelMessages.h b/libraries/metavoxels/src/MetavoxelMessages.h
index 8f819fe3d8..b822f1c561 100644
--- a/libraries/metavoxels/src/MetavoxelMessages.h
+++ b/libraries/metavoxels/src/MetavoxelMessages.h
@@ -61,6 +61,13 @@ class MetavoxelDeltaMessage {
 
 DECLARE_STREAMABLE_METATYPE(MetavoxelDeltaMessage)
 
+/// A message indicating that metavoxel delta information is being sent on a reliable channel.
+class MetavoxelDeltaPendingMessage {
+    STREAMABLE
+};
+
+DECLARE_STREAMABLE_METATYPE(MetavoxelDeltaPendingMessage)
+
 /// A simple streamable edit.
 class MetavoxelEditMessage {
     STREAMABLE
diff --git a/libraries/networking/src/NetworkAccessManager.cpp b/libraries/networking/src/NetworkAccessManager.cpp
index 7e5ba3f66e..e92760d303 100644
--- a/libraries/networking/src/NetworkAccessManager.cpp
+++ b/libraries/networking/src/NetworkAccessManager.cpp
@@ -9,153 +9,19 @@
 //  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
 //
 
-#include <QMetaObject>
-#include <QAbstractNetworkCache>
-#include <QThread>
+#include <QThreadStorage>
 
 #include "NetworkAccessManager.h"
 
+QThreadStorage<NetworkAccessManager*> networkAccessManagers;
+
 NetworkAccessManager& NetworkAccessManager::getInstance() {
-    static NetworkAccessManager sharedInstance;
-    return sharedInstance;
+    if (!networkAccessManagers.hasLocalData()) {
+            networkAccessManagers.setLocalData(new NetworkAccessManager());
+    }
+    
+    return *networkAccessManagers.localData();
 }
 
 NetworkAccessManager::NetworkAccessManager() {
-    qRegisterMetaType<QAbstractNetworkCache*>();
 }
-
-QNetworkReply* NetworkAccessManager::get(const QNetworkRequest& request) {
-    if (QThread::currentThread() != thread()) {
-        QNetworkReply* result;
-        QMetaObject::invokeMethod(this,
-                                  "get",
-                                  Qt::BlockingQueuedConnection,
-                                  Q_RETURN_ARG(QNetworkReply*, result),
-                                  Q_ARG(const QNetworkRequest, request));
-        return result;
-    }
-    return QNetworkAccessManager::get(request);
-}
-
-QNetworkReply* NetworkAccessManager::head(const QNetworkRequest& request) {
-    if (QThread::currentThread() != thread()) {
-        QNetworkReply* result;
-        QMetaObject::invokeMethod(this,
-                                  "head",
-                                  Qt::BlockingQueuedConnection,
-                                  Q_RETURN_ARG(QNetworkReply*, result),
-                                  Q_ARG(const QNetworkRequest, request));
-        return result;
-    }
-    return QNetworkAccessManager::head(request);
-}
-
-QNetworkReply* NetworkAccessManager::post(const QNetworkRequest& request, QIODevice* data) {
-    if (QThread::currentThread() != thread()) {
-        QNetworkReply* result;
-        QMetaObject::invokeMethod(this,
-                                  "post",
-                                  Qt::BlockingQueuedConnection,
-                                  Q_RETURN_ARG(QNetworkReply*, result),
-                                  Q_ARG(const QNetworkRequest, request),
-                                  Q_ARG(QIODevice*, data));
-        return result;
-    }
-    return QNetworkAccessManager::post(request, data);
-}
-
-QNetworkReply* NetworkAccessManager::post(const QNetworkRequest& request, const QByteArray& data) {
-    if (QThread::currentThread() != thread()) {
-        QNetworkReply* result;
-        QMetaObject::invokeMethod(this,
-                                  "post",
-                                  Qt::BlockingQueuedConnection,
-                                  Q_RETURN_ARG(QNetworkReply*, result),
-                                  Q_ARG(const QNetworkRequest, request),
-                                  Q_ARG(const QByteArray, data));
-        return result;
-    }
-    return QNetworkAccessManager::post(request, data);
-}
-
-QNetworkReply* NetworkAccessManager::post(const QNetworkRequest& request, QHttpMultiPart* multiPart) {
-    if (QThread::currentThread() != thread()) {
-        QNetworkReply* result;
-        QMetaObject::invokeMethod(this,
-                                  "post",
-                                  Qt::BlockingQueuedConnection,
-                                  Q_RETURN_ARG(QNetworkReply*, result),
-                                  Q_ARG(const QNetworkRequest, request),
-                                  Q_ARG(QHttpMultiPart*, multiPart));
-        return result;
-    }
-    return QNetworkAccessManager::post(request, multiPart);
-}
-
-QNetworkReply* NetworkAccessManager::put(const QNetworkRequest& request, QIODevice* data) {
-    if (QThread::currentThread() != thread()) {
-        QNetworkReply* result;
-        QMetaObject::invokeMethod(this,
-                                  "put",
-                                  Qt::BlockingQueuedConnection,
-                                  Q_RETURN_ARG(QNetworkReply*, result),
-                                  Q_ARG(const QNetworkRequest, request),
-                                  Q_ARG(QIODevice*, data));
-        return result;
-    }
-    return QNetworkAccessManager::put(request, data);
-}
-
-QNetworkReply* NetworkAccessManager::put(const QNetworkRequest& request, QHttpMultiPart* multiPart) {
-    if (QThread::currentThread() != thread()) {
-        QNetworkReply* result;
-        QMetaObject::invokeMethod(this,
-                                  "put",
-                                  Qt::BlockingQueuedConnection,
-                                  Q_RETURN_ARG(QNetworkReply*, result),
-                                  Q_ARG(const QNetworkRequest, request),
-                                  Q_ARG(QHttpMultiPart*, multiPart));
-        return result;
-    }
-    return QNetworkAccessManager::put(request, multiPart);
-}
-
-QNetworkReply* NetworkAccessManager::put(const QNetworkRequest & request, const QByteArray & data) {
-    if (QThread::currentThread() != thread()) {
-        QNetworkReply* result;
-        QMetaObject::invokeMethod(this,
-                                  "put",
-                                  Qt::BlockingQueuedConnection,
-                                  Q_RETURN_ARG(QNetworkReply*, result),
-                                  Q_ARG(const QNetworkRequest, request),
-                                  Q_ARG(const QByteArray, data));
-        return result;
-    }
-    return QNetworkAccessManager::put(request, data);
-}
-
-
-QNetworkReply* NetworkAccessManager::sendCustomRequest(const QNetworkRequest& request, const QByteArray& verb, QIODevice* data) {
-    if (QThread::currentThread() != thread()) {
-        QNetworkReply* result;
-        QMetaObject::invokeMethod(this,
-                                  "sendCustomRequest",
-                                  Qt::BlockingQueuedConnection,
-                                  Q_RETURN_ARG(QNetworkReply*, result),
-                                  Q_ARG(const QNetworkRequest, request),
-                                  Q_ARG(const QByteArray, verb),
-                                  Q_ARG(QIODevice*, data));
-        return result;
-    }
-    return QNetworkAccessManager::sendCustomRequest(request, verb, data);
-}
-
-void NetworkAccessManager::setCache(QAbstractNetworkCache* cache) {
-    if (QThread::currentThread() != thread()) {
-        QMetaObject::invokeMethod(this,
-                                  "setCache",
-                                  Qt::BlockingQueuedConnection,
-                                  Q_ARG(QAbstractNetworkCache*, cache));
-    }
-    QNetworkAccessManager::setCache(cache);
-}
\ No newline at end of file
diff --git a/libraries/networking/src/NetworkAccessManager.h b/libraries/networking/src/NetworkAccessManager.h
index 1b49cc9dee..9594170518 100644
--- a/libraries/networking/src/NetworkAccessManager.h
+++ b/libraries/networking/src/NetworkAccessManager.h
@@ -13,30 +13,13 @@
 #define hifi_NetworkAccessManager_h
 
 #include <QNetworkAccessManager>
-#include <QNetworkConfiguration>
-#include <QNetworkProxy>
 
-/// Wrapper around QNetworkAccessManager wo that we only use one instance
-/// For any other method you should need, make sure to be on the right thread
-/// or if it is not but is a slot, use QMetaObject::invokeMethod()
-/// In the case what you want to call isn't a slot and you aren't on the same thread,
-/// then add then method to the method to the wrapper with the Q_INVKABLE flag
+/// Wrapper around QNetworkAccessManager to restrict at one instance by thread
 class NetworkAccessManager : public QNetworkAccessManager {
     Q_OBJECT
 public:
     static NetworkAccessManager& getInstance();
     
-    Q_INVOKABLE QNetworkReply* get(const QNetworkRequest& request);
-    Q_INVOKABLE QNetworkReply* head(const QNetworkRequest& request);
-    Q_INVOKABLE QNetworkReply* post(const QNetworkRequest& request, QIODevice* data);
-    Q_INVOKABLE QNetworkReply* post(const QNetworkRequest& request, const QByteArray& data);
-    Q_INVOKABLE QNetworkReply* post(const QNetworkRequest& request, QHttpMultiPart* multiPart);
-    Q_INVOKABLE QNetworkReply* put(const QNetworkRequest& request, QIODevice* data);
-    Q_INVOKABLE QNetworkReply* put(const QNetworkRequest& request, QHttpMultiPart* multiPart);
-    Q_INVOKABLE QNetworkReply* put(const QNetworkRequest& request, const QByteArray& data);
-    Q_INVOKABLE QNetworkReply* sendCustomRequest(const QNetworkRequest& request, const QByteArray& verb, QIODevice* data = 0);
-    Q_INVOKABLE void setCache(QAbstractNetworkCache* cache);
-    
 private:
     NetworkAccessManager();
 };
diff --git a/tests/metavoxels/src/MetavoxelTests.cpp b/tests/metavoxels/src/MetavoxelTests.cpp
index 61ab664310..4132270620 100644
--- a/tests/metavoxels/src/MetavoxelTests.cpp
+++ b/tests/metavoxels/src/MetavoxelTests.cpp
@@ -646,16 +646,23 @@ TestEndpoint::TestEndpoint(Mode mode) :
     Endpoint(SharedNodePointer(), new TestSendRecord(), new TestReceiveRecord()),
     _mode(mode),
     _highPriorityMessagesToSend(0.0f),
-    _reliableMessagesToSend(0.0f) {
+    _reliableMessagesToSend(0.0f),
+    _reliableDeltaChannel(NULL) {
     
     connect(&_sequencer, SIGNAL(receivedHighPriorityMessage(const QVariant&)),
         SLOT(handleHighPriorityMessage(const QVariant&)));
-    
+    connect(_sequencer.getReliableInputChannel(), SIGNAL(receivedMessage(const QVariant&, Bitstream&)),
+        SLOT(handleReliableMessage(const QVariant&, Bitstream&)));
+        
     if (mode == METAVOXEL_CLIENT_MODE) {
         _lod = MetavoxelLOD(glm::vec3(), 0.01f);
+        connect(_sequencer.getReliableInputChannel(RELIABLE_DELTA_CHANNEL_INDEX),
+            SIGNAL(receivedMessage(const QVariant&, Bitstream&)), SLOT(handleReliableMessage(const QVariant&, Bitstream&)));
         return;
     }
     if (mode == METAVOXEL_SERVER_MODE) {
+        connect(&_sequencer, SIGNAL(sendAcknowledged(int)), SLOT(checkReliableDeltaReceived()));
+        
         _data.expand();
         _data.expand();
         
@@ -673,9 +680,6 @@ TestEndpoint::TestEndpoint(Mode mode) :
     // create the object that represents out delta-encoded state
     _localState = new TestSharedObjectA();
     
-    connect(_sequencer.getReliableInputChannel(), SIGNAL(receivedMessage(const QVariant&)),
-        SLOT(handleReliableMessage(const QVariant&)));
-    
     ReliableChannel* secondInput = _sequencer.getReliableInputChannel(1);
     secondInput->setMessagesEnabled(false);
     connect(&secondInput->getBuffer(), SIGNAL(readyRead()), SLOT(readReliableChannel()));
@@ -867,9 +871,6 @@ bool TestEndpoint::simulate(int iterationNumber) {
             
             maxDatagramsPerPacket = qMax(maxDatagramsPerPacket, datagramsSent - oldDatagramsSent);
             maxBytesPerPacket = qMax(maxBytesPerPacket, bytesSent - oldBytesSent);
-            
-            // record the send
-            _sendRecords.append(maybeCreateSendRecord());
         }
         return false;
         
@@ -880,9 +881,6 @@ bool TestEndpoint::simulate(int iterationNumber) {
         out << QVariant::fromValue(state);
         _sequencer.endPacket();
         
-        // record the send
-        _sendRecords.append(maybeCreateSendRecord());
-
     } else if (_mode == METAVOXEL_SERVER_MODE) {
         // make a random change
         MutateVisitor visitor;
@@ -907,15 +905,39 @@ bool TestEndpoint::simulate(int iterationNumber) {
         if (!_lod.isValid()) {
             return false;
         }
+        // if we're sending a reliable delta, wait until it's acknowledged
+        if (_reliableDeltaChannel) {
+            Bitstream& out = _sequencer.startPacket();
+            out << QVariant::fromValue(MetavoxelDeltaPendingMessage());
+            _sequencer.endPacket();
+            return false;
+        }
         Bitstream& out = _sequencer.startPacket();
+        int start = _sequencer.getOutputStream().getUnderlying().device()->pos();
         out << QVariant::fromValue(MetavoxelDeltaMessage());
         PacketRecord* sendRecord = getLastAcknowledgedSendRecord();
         _data.writeDelta(sendRecord->getData(), sendRecord->getLOD(), out, _lod);
-        _sequencer.endPacket();
-       
-        // record the send
-        _sendRecords.append(maybeCreateSendRecord());
-         
+        out.flush();
+        int end = _sequencer.getOutputStream().getUnderlying().device()->pos();
+        if (end > _sequencer.getMaxPacketSize()) {
+            // we need to send the delta on the reliable channel
+            _reliableDeltaChannel = _sequencer.getReliableOutputChannel(RELIABLE_DELTA_CHANNEL_INDEX);
+            _reliableDeltaChannel->startMessage();
+            _reliableDeltaChannel->getBuffer().write(_sequencer.getOutgoingPacketData().constData() + start, end - start);
+            _reliableDeltaChannel->endMessage();
+            
+            _reliableDeltaWriteMappings = out.getAndResetWriteMappings();
+            _reliableDeltaReceivedOffset = _reliableDeltaChannel->getBytesWritten();
+            _reliableDeltaData = _data;
+            _reliableDeltaLOD = _lod;
+            
+            _sequencer.getOutputStream().getUnderlying().device()->seek(start);
+            out << QVariant::fromValue(MetavoxelDeltaPendingMessage());
+            _sequencer.endPacket();
+            
+        } else {
+            _sequencer.endPacket();
+        }
     } else {
         // enqueue some number of high priority messages
         const float MIN_HIGH_PRIORITY_MESSAGES = 0.0f;
@@ -957,9 +979,6 @@ bool TestEndpoint::simulate(int iterationNumber) {
             qDebug() << message;
             return true;
         }
-    
-        // record the send
-        _sendRecords.append(maybeCreateSendRecord());
     }
     maxDatagramsPerPacket = qMax(maxDatagramsPerPacket, datagramsSent - oldDatagramsSent);
     maxBytesPerPacket = qMax(maxBytesPerPacket, bytesSent - oldBytesSent);
@@ -995,7 +1014,7 @@ void TestEndpoint::sendDatagram(const QByteArray& datagram) {
     // some are received out of order
     const float REORDER_PROBABILITY = 0.1f;
     if (randFloat() < REORDER_PROBABILITY * probabilityMultiplier) {
-        const int MIN_DELAY = 1;
+        const int MIN_DELAY = 2;
         const int MAX_DELAY = 5;
         // have to copy the datagram; the one we're passed is a reference to a shared buffer
         _delayedDatagrams.append(ByteArrayIntPair(QByteArray(datagram.constData(), datagram.size()),
@@ -1008,58 +1027,32 @@ void TestEndpoint::sendDatagram(const QByteArray& datagram) {
         }
     }
     
-    _other->parseData(datagram);
+    _delayedDatagrams.append(ByteArrayIntPair(QByteArray(datagram.constData(), datagram.size()), 1));
 }
 
 void TestEndpoint::readMessage(Bitstream& in) {
     if (_mode == CONGESTION_MODE) {
         QVariant message;
         in >> message;
-        
-        // record the receipt
-        _receiveRecords.append(maybeCreateReceiveRecord());
         return;
     }
     if (_mode == METAVOXEL_CLIENT_MODE) {
         QVariant message;
         in >> message;
         handleMessage(message, in);
-    
-        // deep-compare data to sent version
-        int packetNumber = _sequencer.getIncomingPacketNumber();
-        foreach (PacketRecord* record, _other->_sendRecords) {
-            TestSendRecord* sendRecord = static_cast<TestSendRecord*>(record);
-            if (sendRecord->getPacketNumber() == packetNumber) {
-                if (!sendRecord->getData().deepEquals(_data, getLastAcknowledgedSendRecord()->getLOD())) {
-                    qDebug() << "Sent/received metavoxel data mismatch.";
-                    exit(true);
-                }
-                break;
-            }
-        }
-        
-        // record the receipt
-        _receiveRecords.append(maybeCreateReceiveRecord());
         return;
     }
     if (_mode == METAVOXEL_SERVER_MODE) {
         QVariant message;
         in >> message;
         handleMessage(message, in);
-        
-        // record the receipt
-        _receiveRecords.append(maybeCreateReceiveRecord());
         return;
     }
-
     SequencedTestMessage message;
     in >> message;
     
     _remoteState = message.state;
     
-    // record the receipt
-    _receiveRecords.append(maybeCreateReceiveRecord());
-    
     for (QList<SequencedTestMessage>::iterator it = _other->_unreliableMessagesSent.begin();
             it != _other->_unreliableMessagesSent.end(); it++) {
         if (it->sequenceNumber == message.sequenceNumber) {
@@ -1088,8 +1081,16 @@ void TestEndpoint::handleMessage(const QVariant& message, Bitstream& in) {
     
     } else if (userType == MetavoxelDeltaMessage::Type) {
         PacketRecord* receiveRecord = getLastAcknowledgedReceiveRecord();
-        _data.readDelta(receiveRecord->getData(), receiveRecord->getLOD(), in, getLastAcknowledgedSendRecord()->getLOD());
+        _data.readDelta(receiveRecord->getData(), receiveRecord->getLOD(), in,
+            _dataLOD = getLastAcknowledgedSendRecord()->getLOD());
+        compareMetavoxelData();
     
+    } else if (userType == MetavoxelDeltaPendingMessage::Type) {
+        if (!_reliableDeltaChannel) {
+            _reliableDeltaChannel = _sequencer.getReliableInputChannel(RELIABLE_DELTA_CHANNEL_INDEX);
+            _reliableDeltaChannel->getBitstream().copyPersistentMappings(_sequencer.getInputStream());
+            _reliableDeltaLOD = getLastAcknowledgedSendRecord()->getLOD();
+        }
     } else if (userType == QMetaType::QVariantList) {
         foreach (const QVariant& element, message.toList()) {
             handleMessage(element, in);
@@ -1098,13 +1099,15 @@ void TestEndpoint::handleMessage(const QVariant& message, Bitstream& in) {
 }
 
 PacketRecord* TestEndpoint::maybeCreateSendRecord() const {
+    if (_reliableDeltaChannel) {
+        return new TestSendRecord(_reliableDeltaLOD, _reliableDeltaData, _localState, _sequencer.getOutgoingPacketNumber());
+    }
     return new TestSendRecord(_lod, (_mode == METAVOXEL_CLIENT_MODE) ? MetavoxelData() : _data,
         _localState, _sequencer.getOutgoingPacketNumber());
 }
 
 PacketRecord* TestEndpoint::maybeCreateReceiveRecord() const {
-    return new TestReceiveRecord(getLastAcknowledgedSendRecord()->getLOD(),
-        (_mode == METAVOXEL_SERVER_MODE) ? MetavoxelData() : _data, _remoteState);
+    return new TestReceiveRecord(_dataLOD, (_mode == METAVOXEL_SERVER_MODE) ? MetavoxelData() : _data, _remoteState);
 }
 
 void TestEndpoint::handleHighPriorityMessage(const QVariant& message) {
@@ -1121,7 +1124,16 @@ void TestEndpoint::handleHighPriorityMessage(const QVariant& message) {
     highPriorityMessagesReceived++;
 }
 
-void TestEndpoint::handleReliableMessage(const QVariant& message) {
+void TestEndpoint::handleReliableMessage(const QVariant& message, Bitstream& in) {
+    if (message.userType() == MetavoxelDeltaMessage::Type) {
+        PacketRecord* receiveRecord = getLastAcknowledgedReceiveRecord();
+        _data.readDelta(receiveRecord->getData(), receiveRecord->getLOD(), in, _dataLOD = _reliableDeltaLOD);
+        _sequencer.getInputStream().persistReadMappings(in.getAndResetReadMappings());
+        in.clearPersistentMappings();
+        compareMetavoxelData();
+        _reliableDeltaChannel = NULL;
+        return;
+    }
     if (message.userType() == ClearSharedObjectMessage::Type ||
             message.userType() == ClearMainChannelSharedObjectMessage::Type) {
         return;
@@ -1150,6 +1162,33 @@ void TestEndpoint::readReliableChannel() {
     streamedBytesReceived += bytes.size();
 }
 
+void TestEndpoint::checkReliableDeltaReceived() {
+    if (!_reliableDeltaChannel || _reliableDeltaChannel->getOffset() < _reliableDeltaReceivedOffset) {
+        return;
+    }
+    _sequencer.getOutputStream().persistWriteMappings(_reliableDeltaWriteMappings);
+    _reliableDeltaWriteMappings = Bitstream::WriteMappings();
+    _reliableDeltaData = MetavoxelData();
+    _reliableDeltaChannel = NULL;
+}
+
+void TestEndpoint::compareMetavoxelData() {
+    // deep-compare data to sent version
+    int packetNumber = _sequencer.getIncomingPacketNumber();
+    foreach (PacketRecord* record, _other->_sendRecords) {
+        TestSendRecord* sendRecord = static_cast<TestSendRecord*>(record);
+        if (sendRecord->getPacketNumber() == packetNumber) {
+            if (!sendRecord->getData().deepEquals(_data, getLastAcknowledgedSendRecord()->getLOD())) {
+                qDebug() << "Sent/received metavoxel data mismatch.";
+                exit(true);
+            }
+            return;
+        }
+    }
+    qDebug() << "Received metavoxel data with no corresponding send." << packetNumber;
+    exit(true);
+}
+
 TestSharedObjectA::TestSharedObjectA(float foo, TestEnum baz, TestFlags bong) :
         _foo(foo),
         _baz(baz),
diff --git a/tests/metavoxels/src/MetavoxelTests.h b/tests/metavoxels/src/MetavoxelTests.h
index 476a8c6295..5d719ccfdf 100644
--- a/tests/metavoxels/src/MetavoxelTests.h
+++ b/tests/metavoxels/src/MetavoxelTests.h
@@ -64,17 +64,21 @@ protected:
 private slots:
    
     void handleHighPriorityMessage(const QVariant& message);
-    void handleReliableMessage(const QVariant& message);
+    void handleReliableMessage(const QVariant& message, Bitstream& in);
     void readReliableChannel();
+    void checkReliableDeltaReceived();
 
 private:
     
+    void compareMetavoxelData();
+    
     Mode _mode;
     
     SharedObjectPointer _localState;
     SharedObjectPointer _remoteState;
     
     MetavoxelData _data;
+    MetavoxelLOD _dataLOD;
     MetavoxelLOD _lod;
     
     SharedObjectPointer _sphere;
@@ -94,6 +98,12 @@ private:
     float _reliableMessagesToSend;
     QVariantList _reliableMessagesSent;
     CircularBuffer _dataStreamed;
+    
+    ReliableChannel* _reliableDeltaChannel;
+    int _reliableDeltaReceivedOffset;
+    MetavoxelData _reliableDeltaData;
+    MetavoxelLOD _reliableDeltaLOD;
+    Bitstream::WriteMappings _reliableDeltaWriteMappings;
 };
 
 /// A simple shared object.