diff --git a/domain-server/resources/describe-settings.json b/domain-server/resources/describe-settings.json
index 8a7d03ba75..4006673cad 100644
--- a/domain-server/resources/describe-settings.json
+++ b/domain-server/resources/describe-settings.json
@@ -863,15 +863,6 @@
           "help": "The path to the directory assets are stored in.<br/>If this path is relative, it will be relative to the application data directory.<br/>If you change this path you will need to manually copy any existing assets from the previous directory.",
           "default": "",
           "advanced": true
-        },
-        {
-          "name": "max_bandwidth",
-          "type": "double",
-          "label": "Max Bandwidth Per User",
-          "help": "The maximum upstream bandwidth each user can use (in Mb/s).",
-          "placeholder": "10.0",
-          "default": "",
-          "advanced": true
         }
       ]
     },
diff --git a/interface/CMakeLists.txt b/interface/CMakeLists.txt
index 9c564f6518..b43376c374 100644
--- a/interface/CMakeLists.txt
+++ b/interface/CMakeLists.txt
@@ -41,8 +41,10 @@ endif ()
 
 if (ANDROID)
   set(PLATFORM_QT_COMPONENTS AndroidExtras)
+  set(PLATFORM_QT_LIBRARIES Qt5::AndroidExtras)
 else ()
   set(PLATFORM_QT_COMPONENTS WebEngine WebEngineWidgets)
+  set(PLATFORM_QT_LIBRARIES Qt5::WebEngine Qt5::WebEngineWidgets)
 endif ()
 
 find_package(
@@ -244,7 +246,8 @@ target_link_libraries(
   ${TARGET_NAME}
   Qt5::Gui Qt5::Network Qt5::Multimedia Qt5::OpenGL
   Qt5::Qml Qt5::Quick Qt5::Script Qt5::Svg
-  Qt5::WebChannel Qt5::WebEngine 
+  Qt5::WebChannel Qt5::WebEngine
+  ${PLATFORM_QT_LIBRARIES}
 )
 
 if (UNIX)
diff --git a/interface/resources/qml/AddressBarDialog.qml b/interface/resources/qml/AddressBarDialog.qml
index f2af980010..7c54a6a626 100644
--- a/interface/resources/qml/AddressBarDialog.qml
+++ b/interface/resources/qml/AddressBarDialog.qml
@@ -279,6 +279,7 @@ Window {
                 verticalCenter: backgroundImage.verticalCenter;
                 horizontalCenter: scroll.horizontalCenter;
             }
+            z: 100
         }
 
         HifiControls.Keyboard {
diff --git a/interface/resources/qml/LoginDialog/CompleteProfileBody.qml b/interface/resources/qml/LoginDialog/CompleteProfileBody.qml
index fc7eac3d00..f1b36ff6a7 100644
--- a/interface/resources/qml/LoginDialog/CompleteProfileBody.qml
+++ b/interface/resources/qml/LoginDialog/CompleteProfileBody.qml
@@ -29,8 +29,9 @@ Item {
         readonly property int maxHeight: 720
 
         function resize() {
-            var targetWidth = Math.max(titleWidth, additionalTextContainer.contentWidth)
-            var targetHeight = 4 * hifi.dimensions.contentSpacing.y + buttons.height + additionalTextContainer.height
+            var targetWidth = Math.max(titleWidth, Math.max(additionalTextContainer.contentWidth,
+                                                            termsContainer.contentWidth))
+            var targetHeight = 5 * hifi.dimensions.contentSpacing.y + buttons.height + additionalTextContainer.height + termsContainer.height
 
             root.width = Math.max(d.minWidth, Math.min(d.maxWidth, targetWidth))
             root.height = Math.max(d.minHeight, Math.min(d.maxHeight, targetHeight))
@@ -43,7 +44,7 @@ Item {
             top: parent.top
             horizontalCenter: parent.horizontalCenter
             margins: 0
-            topMargin: 3 * hifi.dimensions.contentSpacing.y
+            topMargin: 2 * hifi.dimensions.contentSpacing.y
         }
         spacing: hifi.dimensions.contentSpacing.x
         onHeightChanged: d.resize(); onWidthChanged: d.resize();
@@ -91,6 +92,25 @@ Item {
         }
     }
 
+    InfoItem {
+        id: termsContainer
+        anchors {
+            top: additionalTextContainer.bottom
+            left: parent.left
+            margins: 0
+            topMargin: 2 * hifi.dimensions.contentSpacing.y
+        }
+
+        text: qsTr("By creating this user profile, you agree to <a href='https://highfidelity.com/terms'>High Fidelity's Terms of Service</a>")
+        wrapMode: Text.WordWrap
+        color: hifi.colors.baseGrayHighlight
+        lineHeight: 1
+        lineHeightMode: Text.ProportionalHeight
+        horizontalAlignment: Text.AlignHCenter
+
+        onLinkActivated: loginDialog.openUrl(link)
+    }
+
     Component.onCompleted: {
         root.title = qsTr("Complete Your Profile")
         root.iconText = "<"
diff --git a/interface/resources/qml/LoginDialog/LinkAccountBody.qml b/interface/resources/qml/LoginDialog/LinkAccountBody.qml
index e1d7a639da..fbcb3d5e37 100644
--- a/interface/resources/qml/LoginDialog/LinkAccountBody.qml
+++ b/interface/resources/qml/LoginDialog/LinkAccountBody.qml
@@ -42,8 +42,14 @@ Item {
 
         function resize() {
             var targetWidth = Math.max(titleWidth, form.contentWidth);
-            var targetHeight =  hifi.dimensions.contentSpacing.y + mainTextContainer.height
-                    + 4 * hifi.dimensions.contentSpacing.y + form.height + hifi.dimensions.contentSpacing.y + buttons.height;
+            var targetHeight =  hifi.dimensions.contentSpacing.y + mainTextContainer.height +
+                            4 * hifi.dimensions.contentSpacing.y + form.height +
+                                hifi.dimensions.contentSpacing.y + buttons.height;
+
+            if (additionalInformation.visible) {
+                targetWidth = Math.max(targetWidth, additionalInformation.width);
+                targetHeight += hifi.dimensions.contentSpacing.y + additionalInformation.height
+            }
 
             root.width = Math.max(d.minWidth, Math.min(d.maxWidth, targetWidth));
             root.height = Math.max(d.minHeight, Math.min(d.maxHeight, targetHeight))
@@ -136,6 +142,25 @@ Item {
 
     }
 
+    InfoItem {
+        id: additionalInformation
+        anchors {
+            top: form.bottom
+            left: parent.left
+            margins: 0
+            topMargin: hifi.dimensions.contentSpacing.y
+        }
+
+        visible: loginDialog.isSteamRunning()
+
+        text: qsTr("Your steam account informations will not be exposed to other users.")
+        wrapMode: Text.WordWrap
+        color: hifi.colors.baseGrayHighlight
+        lineHeight: 1
+        lineHeightMode: Text.ProportionalHeight
+        horizontalAlignment: Text.AlignHCenter
+    }
+
     // Override ScrollingWindow's keyboard that would be at very bottom of dialog.
     Keyboard {
         raised: keyboardEnabled && keyboardRaised
diff --git a/interface/resources/qml/LoginDialog/UsernameCollisionBody.qml b/interface/resources/qml/LoginDialog/UsernameCollisionBody.qml
index b949c660d6..eafe9e4b47 100644
--- a/interface/resources/qml/LoginDialog/UsernameCollisionBody.qml
+++ b/interface/resources/qml/LoginDialog/UsernameCollisionBody.qml
@@ -27,6 +27,13 @@ Item {
         loginDialog.createAccountFromStream(textField.text)
     }
 
+
+    property bool keyboardEnabled: false
+    property bool keyboardRaised: false
+    property bool punctuationMode: false
+
+    onKeyboardRaisedChanged: d.resize();
+
     QtObject {
         id: d
         readonly property int minWidth: 480
@@ -35,15 +42,16 @@ Item {
         readonly property int maxHeight: 720
 
         function resize() {
-            var targetWidth = Math.max(titleWidth, Math.max(mainTextContainer.contentWidth,
-                                                            termsContainer.contentWidth))
+            var targetWidth = Math.max(titleWidth, mainTextContainer.contentWidth)
             var targetHeight =  mainTextContainer.height +
-                                2 * hifi.dimensions.contentSpacing.y + textField.height +
-                                5 * hifi.dimensions.contentSpacing.y + termsContainer.height +
-                                1 * hifi.dimensions.contentSpacing.y + buttons.height
+                                hifi.dimensions.contentSpacing.y + textField.height +
+                                hifi.dimensions.contentSpacing.y + buttons.height
 
             root.width = Math.max(d.minWidth, Math.min(d.maxWidth, targetWidth))
             root.height = Math.max(d.minHeight, Math.min(d.maxHeight, targetHeight))
+                    + (keyboardEnabled && keyboardRaised ? (200 + 2 * hifi.dimensions.contentSpacing.y) : hifi.dimensions.contentSpacing.y)
+
+            height = root.height
         }
     }
 
@@ -71,39 +79,32 @@ Item {
             top: mainTextContainer.bottom
             left: parent.left
             margins: 0
-            topMargin: 2 * hifi.dimensions.contentSpacing.y
+            topMargin: hifi.dimensions.contentSpacing.y
         }
         width: 250
 
         placeholderText: "Choose your own"
     }
 
-    InfoItem {
-        id: termsContainer
+    // Override ScrollingWindow's keyboard that would be at very bottom of dialog.
+    Keyboard {
+        raised: keyboardEnabled && keyboardRaised
+        numeric: punctuationMode
         anchors {
-            top: textField.bottom
             left: parent.left
-            margins: 0
-            topMargin: 3 * hifi.dimensions.contentSpacing.y
+            right: parent.right
+            bottom: buttons.top
+            bottomMargin: keyboardRaised ? 2 * hifi.dimensions.contentSpacing.y : 0
         }
-
-        text: qsTr("By creating this user profile, you agree to <a href='https://highfidelity.com/terms'>High Fidelity's Terms of Service</a>")
-        wrapMode: Text.WordWrap
-        color: hifi.colors.baseGrayHighlight
-        lineHeight: 1
-        lineHeightMode: Text.ProportionalHeight
-        horizontalAlignment: Text.AlignHCenter
-
-        onLinkActivated: loginDialog.openUrl(link)
     }
 
     Row {
         id: buttons
         anchors {
-            top: termsContainer.bottom
+            bottom: parent.bottom
             right: parent.right
             margins: 0
-            topMargin: 1 * hifi.dimensions.contentSpacing.y
+            topMargin: hifi.dimensions.contentSpacing.y
         }
         spacing: hifi.dimensions.contentSpacing.x
         onHeightChanged: d.resize(); onWidthChanged: d.resize();
@@ -130,8 +131,10 @@ Item {
     Component.onCompleted: {
         root.title = qsTr("Complete Your Profile")
         root.iconText = "<"
+        keyboardEnabled = HMD.active;
         d.resize();
     }
+
     Connections {
         target: loginDialog
         onHandleCreateCompleted: {
diff --git a/interface/resources/qml/controls-uit/BaseWebView.qml b/interface/resources/qml/controls-uit/BaseWebView.qml
index a5b724f113..763e6530fb 100644
--- a/interface/resources/qml/controls-uit/BaseWebView.qml
+++ b/interface/resources/qml/controls-uit/BaseWebView.qml
@@ -10,10 +10,10 @@
 
 import QtQuick 2.5
 import QtWebEngine 1.2
+import HFWebEngineProfile 1.0
 
 WebEngineView {
     id: root
-    property var newUrl;
 
     profile: desktop.browserProfile
 
@@ -25,28 +25,6 @@ WebEngineView {
         });
     }
 
-    // FIXME hack to get the URL with the auth token included.  Remove when we move to Qt 5.6
-    Timer {
-        id: urlReplacementTimer
-        running: false
-        repeat: false
-        interval: 50
-        onTriggered: url = newUrl;
-    }
-
-    onUrlChanged: {
-        var originalUrl = url.toString();
-        newUrl = urlHandler.fixupUrl(originalUrl).toString();
-        if (newUrl !== originalUrl) {
-            root.stop();
-            if (urlReplacementTimer.running) {
-                console.warn("Replacement timer already running");
-                return;
-            }
-            urlReplacementTimer.start();
-        }
-    }
-
     onLoadingChanged: {
         // Required to support clicking on "hifi://" links
         if (WebEngineView.LoadStartedStatus == loadRequest.status) {
diff --git a/interface/resources/qml/controls/WebView.qml b/interface/resources/qml/controls/WebView.qml
index 1056a3b75e..abaf11a8e2 100644
--- a/interface/resources/qml/controls/WebView.qml
+++ b/interface/resources/qml/controls/WebView.qml
@@ -2,6 +2,7 @@ import QtQuick 2.5
 import QtWebEngine 1.1
 import QtWebChannel 1.0
 import "../controls-uit" as HiFiControls
+import HFWebEngineProfile 1.0
 
 Item {
     property alias url: root.url
@@ -31,6 +32,11 @@ Item {
         width: parent.width
         height: keyboardEnabled && keyboardRaised ? parent.height - keyboard.height : parent.height
 
+        profile: HFWebEngineProfile {
+            id: webviewProfile
+            storageName: "qmlWebEngine"
+        }
+
         // creates a global EventBridge object.
         WebEngineScript {
             id: createGlobalEventBridge
@@ -62,28 +68,6 @@ Item {
             root.profile.httpUserAgent = "Mozilla/5.0 Chrome (HighFidelityInterface)";
         }
 
-        // FIXME hack to get the URL with the auth token included.  Remove when we move to Qt 5.6
-        Timer {
-            id: urlReplacementTimer
-            running: false
-            repeat: false
-            interval: 50
-            onTriggered: url = root.newUrl;
-        }
-
-        onUrlChanged: {
-            var originalUrl = url.toString();
-            root.newUrl = urlHandler.fixupUrl(originalUrl).toString();
-            if (root.newUrl !== originalUrl) {
-                root.stop();
-                if (urlReplacementTimer.running) {
-                    console.warn("Replacement timer already running");
-                    return;
-                }
-                urlReplacementTimer.start();
-            }
-        }
-
         onFeaturePermissionRequested: {
             grantFeaturePermission(securityOrigin, feature, true);
         }
diff --git a/interface/resources/qml/desktop/Desktop.qml b/interface/resources/qml/desktop/Desktop.qml
index ea2f048c1f..b207087be0 100644
--- a/interface/resources/qml/desktop/Desktop.qml
+++ b/interface/resources/qml/desktop/Desktop.qml
@@ -33,7 +33,7 @@ FocusScope {
         }
 
     }
-
+    
     onHeightChanged: d.handleSizeChanged();
 
     onWidthChanged: d.handleSizeChanged();
diff --git a/interface/resources/qml/hifi/Desktop.qml b/interface/resources/qml/hifi/Desktop.qml
index 7e523bbb70..b4fe773364 100644
--- a/interface/resources/qml/hifi/Desktop.qml
+++ b/interface/resources/qml/hifi/Desktop.qml
@@ -2,6 +2,7 @@ import QtQuick 2.5
 import QtQuick.Controls 1.4
 import QtWebEngine 1.1;
 import Qt.labs.settings 1.0
+import HFWebEngineProfile 1.0
 
 import "../desktop" as OriginalDesktop
 import ".."
@@ -20,17 +21,14 @@ OriginalDesktop.Desktop {
         onEntered: ApplicationCompositor.reticleOverDesktop = true
         onExited: ApplicationCompositor.reticleOverDesktop = false
         acceptedButtons: Qt.NoButton
-		
-
     }
 
     // The tool window, one instance
     property alias toolWindow: toolWindow
     ToolWindow { id: toolWindow }
 
-    property var browserProfile: WebEngineProfile {
+    property var browserProfile: HFWebEngineProfile {
         id: webviewProfile
-        httpUserAgent: "Chrome/48.0 (HighFidelityInterface)"
         storageName: "qmlWebEngine"
     }
 
@@ -127,5 +125,3 @@ OriginalDesktop.Desktop {
         return result;
     }
 }
-
-
diff --git a/interface/src/Application.cpp b/interface/src/Application.cpp
index 4351ffd230..beefc9c67b 100644
--- a/interface/src/Application.cpp
+++ b/interface/src/Application.cpp
@@ -34,6 +34,8 @@
 #include <QtQml/QQmlEngine>
 #include <QtQuick/QQuickWindow>
 
+#include <QtWebEngineWidgets/QWebEngineProfile>
+
 #include <QtWidgets/QDesktopWidget>
 #include <QtWidgets/QMessageBox>
 
@@ -126,6 +128,7 @@
 #include "InterfaceLogging.h"
 #include "LODManager.h"
 #include "ModelPackager.h"
+#include "networking/HFWebEngineProfile.h"
 #include "scripting/AccountScriptingInterface.h"
 #include "scripting/AssetMappingsScriptingInterface.h"
 #include "scripting/AudioDeviceScriptingInterface.h"
@@ -1698,6 +1701,7 @@ void Application::initializeUi() {
     UpdateDialog::registerType();
     qmlRegisterType<Preference>("Hifi", 1, 0, "Preference");
 
+    qmlRegisterType<HFWebEngineProfile>("HFWebEngineProfile", 1, 0, "HFWebEngineProfile");
 
     auto offscreenUi = DependencyManager::get<OffscreenUi>();
     offscreenUi->create(_glWidget->qglContext());
diff --git a/interface/src/avatar/Avatar.cpp b/interface/src/avatar/Avatar.cpp
index 717a0eeac7..94632d5e45 100644
--- a/interface/src/avatar/Avatar.cpp
+++ b/interface/src/avatar/Avatar.cpp
@@ -603,14 +603,14 @@ void Avatar::fixupModelsInScene() {
         _skeletonModel->removeFromScene(scene, pendingChanges);
         _skeletonModel->addToScene(scene, pendingChanges);
     }
-    for (auto& attachmentModel : _attachmentModels) {
+    for (auto attachmentModel : _attachmentModels) {
         if (attachmentModel->isRenderable() && attachmentModel->needsFixupInScene()) {
             attachmentModel->removeFromScene(scene, pendingChanges);
             attachmentModel->addToScene(scene, pendingChanges);
         }
     }
 
-    for (auto& attachmentModelToRemove : _attachmentsToRemove) {
+    for (auto attachmentModelToRemove : _attachmentsToRemove) {
         attachmentModelToRemove->removeFromScene(scene, pendingChanges);
     }
     _attachmentsToDelete.insert(_attachmentsToDelete.end(), _attachmentsToRemove.begin(), _attachmentsToRemove.end());
diff --git a/interface/src/networking/HFWebEngineProfile.cpp b/interface/src/networking/HFWebEngineProfile.cpp
new file mode 100644
index 0000000000..6b377fa900
--- /dev/null
+++ b/interface/src/networking/HFWebEngineProfile.cpp
@@ -0,0 +1,27 @@
+//
+//  HFWebEngineProfile.cpp
+//  interface/src/networking
+//
+//  Created by Stephen Birarda on 2016-10-17.
+//  Copyright 2016 High Fidelity, Inc.
+//
+//  Distributed under the Apache License, Version 2.0.
+//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
+//
+
+#include "HFWebEngineProfile.h"
+
+#include "HFWebEngineRequestInterceptor.h"
+
+static const QString QML_WEB_ENGINE_STORAGE_NAME = "qmlWebEngine";
+
+HFWebEngineProfile::HFWebEngineProfile(QObject* parent) :
+    QQuickWebEngineProfile(parent)
+{
+    static const QString WEB_ENGINE_USER_AGENT = "Chrome/48.0 (HighFidelityInterface)";
+    setHttpUserAgent(WEB_ENGINE_USER_AGENT);
+
+    // we use the HFWebEngineRequestInterceptor to make sure that web requests are authenticated for the interface user
+    auto requestInterceptor = new HFWebEngineRequestInterceptor(this);
+    setRequestInterceptor(requestInterceptor);
+}
diff --git a/interface/src/networking/HFWebEngineProfile.h b/interface/src/networking/HFWebEngineProfile.h
new file mode 100644
index 0000000000..5c7655479e
--- /dev/null
+++ b/interface/src/networking/HFWebEngineProfile.h
@@ -0,0 +1,25 @@
+//
+//  HFWebEngineProfile.h
+//  interface/src/networking
+//
+//  Created by Stephen Birarda on 2016-10-17.
+//  Copyright 2016 High Fidelity, Inc.
+//
+//  Distributed under the Apache License, Version 2.0.
+//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
+//
+
+#pragma once
+
+#ifndef hifi_HFWebEngineProfile_h
+#define hifi_HFWebEngineProfile_h
+
+#include <QtWebEngine/QQuickWebEngineProfile>
+
+class HFWebEngineProfile : public QQuickWebEngineProfile {
+public:
+    HFWebEngineProfile(QObject* parent = Q_NULLPTR);
+};
+
+
+#endif // hifi_HFWebEngineProfile_h
diff --git a/interface/src/networking/HFWebEngineRequestInterceptor.cpp b/interface/src/networking/HFWebEngineRequestInterceptor.cpp
new file mode 100644
index 0000000000..9c3f0b232e
--- /dev/null
+++ b/interface/src/networking/HFWebEngineRequestInterceptor.cpp
@@ -0,0 +1,40 @@
+//
+//  HFWebEngineRequestInterceptor.cpp
+//  interface/src/networking
+//
+//  Created by Stephen Birarda on 2016-10-14.
+//  Copyright 2016 High Fidelity, Inc.
+//
+//  Distributed under the Apache License, Version 2.0.
+//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
+//
+
+#include "HFWebEngineRequestInterceptor.h"
+
+#include <QtCore/QDebug>
+
+#include <AccountManager.h>
+
+bool isAuthableHighFidelityURL(const QUrl& url) {
+    static const QStringList HF_HOSTS = {
+        "highfidelity.com", "highfidelity.io",
+        "metaverse.highfidelity.com", "metaverse.highfidelity.io"
+    };
+
+    return url.scheme() == "https" && HF_HOSTS.contains(url.host());
+}
+
+void HFWebEngineRequestInterceptor::interceptRequest(QWebEngineUrlRequestInfo& info) {
+    // check if this is a request to a highfidelity URL
+    if (isAuthableHighFidelityURL(info.requestUrl())) {
+        // if we have an access token, add it to the right HTTP header for authorization
+        auto accountManager = DependencyManager::get<AccountManager>();
+
+        if (accountManager->hasValidAccessToken()) {
+            static const QString OAUTH_AUTHORIZATION_HEADER = "Authorization";
+
+            QString bearerTokenString = "Bearer " + accountManager->getAccountInfo().getAccessToken().token;
+            info.setHttpHeader(OAUTH_AUTHORIZATION_HEADER.toLocal8Bit(), bearerTokenString.toLocal8Bit());
+        }
+    }
+}
diff --git a/interface/src/networking/HFWebEngineRequestInterceptor.h b/interface/src/networking/HFWebEngineRequestInterceptor.h
new file mode 100644
index 0000000000..a4c308426c
--- /dev/null
+++ b/interface/src/networking/HFWebEngineRequestInterceptor.h
@@ -0,0 +1,26 @@
+//
+//  HFWebEngineRequestInterceptor.h
+//  interface/src/networking
+//
+//  Created by Stephen Birarda on 2016-10-14.
+//  Copyright 2016 High Fidelity, Inc.
+//
+//  Distributed under the Apache License, Version 2.0.
+//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
+//
+
+#pragma once
+
+#ifndef hifi_HFWebEngineRequestInterceptor_h
+#define hifi_HFWebEngineRequestInterceptor_h
+
+#include <QWebEngineUrlRequestInterceptor>
+
+class HFWebEngineRequestInterceptor : public QWebEngineUrlRequestInterceptor {
+public:
+    HFWebEngineRequestInterceptor(QObject* parent) : QWebEngineUrlRequestInterceptor(parent) {};
+
+    virtual void interceptRequest(QWebEngineUrlRequestInfo& info) override;
+};
+
+#endif // hifi_HFWebEngineRequestInterceptor_h
diff --git a/libraries/gl/src/gl/OffscreenQmlSurface.cpp b/libraries/gl/src/gl/OffscreenQmlSurface.cpp
index d16968f370..8bf510bb2a 100644
--- a/libraries/gl/src/gl/OffscreenQmlSurface.cpp
+++ b/libraries/gl/src/gl/OffscreenQmlSurface.cpp
@@ -40,19 +40,6 @@
 #include "TextureRecycler.h"
 #include "Context.h"
 
-QString fixupHifiUrl(const QString& urlString) {
-    static const QString ACCESS_TOKEN_PARAMETER = "access_token";
-    static const QString ALLOWED_HOST = "metaverse.highfidelity.com";
-    QUrl url(urlString);
-    QUrlQuery query(url);
-    if (url.host() == ALLOWED_HOST && query.allQueryItemValues(ACCESS_TOKEN_PARAMETER).empty()) {
-        auto accountManager = DependencyManager::get<AccountManager>();
-        query.addQueryItem(ACCESS_TOKEN_PARAMETER, accountManager->getAccountInfo().getAccessToken().token);
-        url.setQuery(query.query());
-        return url.toString();
-    }
-    return urlString;
-}
 
 class UrlHandler : public QObject {
     Q_OBJECT
@@ -66,11 +53,6 @@ public:
         static auto handler = dynamic_cast<AbstractUriHandler*>(qApp);
         return handler->acceptURL(url);
     }
-
-    // FIXME hack for authentication, remove when we migrate to Qt 5.6
-    Q_INVOKABLE QString fixupUrl(const QString& originalUrl) {
-        return fixupHifiUrl(originalUrl);
-    }
 };
 
 // Time between receiving a request to render the offscreen UI actually triggering
diff --git a/libraries/networking/src/udt/BasePacket.h b/libraries/networking/src/udt/BasePacket.h
index 33b8020d3c..d9b624b595 100644
--- a/libraries/networking/src/udt/BasePacket.h
+++ b/libraries/networking/src/udt/BasePacket.h
@@ -18,6 +18,8 @@
 
 #include <QtCore/QIODevice>
 
+#include <PortableHighResolutionClock.h>
+
 #include "../HifiSockAddr.h"
 #include "Constants.h"
 
@@ -80,6 +82,9 @@ public:
 
     qint64 writeString(const QString& string);
     QString readString();
+
+    void setReceiveTime(p_high_resolution_clock::time_point receiveTime) { _receiveTime = receiveTime; }
+    p_high_resolution_clock::time_point getReceiveTime() const { return _receiveTime; }
    
     template<typename T> qint64 peekPrimitive(T* data);
     template<typename T> qint64 readPrimitive(T* data);
@@ -108,6 +113,8 @@ protected:
     qint64 _payloadSize = 0;          // How much of the payload is actually used
     
     HifiSockAddr _senderSockAddr;  // sender address for packet (only used on receiving end)
+
+    p_high_resolution_clock::time_point _receiveTime; // captures the time the packet received (only used on receiving end)
 };
 
 template<typename T> qint64 BasePacket::peekPrimitive(T* data) {
diff --git a/libraries/networking/src/udt/CongestionControl.cpp b/libraries/networking/src/udt/CongestionControl.cpp
index 5826bfa11c..7ade4f004f 100644
--- a/libraries/networking/src/udt/CongestionControl.cpp
+++ b/libraries/networking/src/udt/CongestionControl.cpp
@@ -45,11 +45,11 @@ DefaultCC::DefaultCC() :
 {
     _mss = udt::MAX_PACKET_SIZE_WITH_UDP_HEADER;
     
-    _congestionWindowSize = 16.0;
+    _congestionWindowSize = 16;
     setPacketSendPeriod(1.0);
 }
 
-void DefaultCC::onACK(SequenceNumber ackNum) {
+bool DefaultCC::onACK(SequenceNumber ackNum, p_high_resolution_clock::time_point receiveTime) {
     double increase = 0;
     
     // Note from UDT original code:
@@ -61,7 +61,7 @@ void DefaultCC::onACK(SequenceNumber ackNum) {
     // we will only adjust once per sync interval so check that it has been at least that long now
     auto now = p_high_resolution_clock::now();
     if (duration_cast<microseconds>(now - _lastRCTime).count() < synInterval()) {
-        return;
+        return false;
     }
     
     // our last rate increase time is now
@@ -93,13 +93,13 @@ void DefaultCC::onACK(SequenceNumber ackNum) {
     
     // during slow start we perform no rate increases
     if (_slowStart) {
-        return;
+        return false;
     }
     
     // if loss has happened since the last rate increase we do not perform another increase
     if (_loss) {
         _loss = false;
-        return;
+        return false;
     }
     
     double capacitySpeedDelta = (_bandwidth - USECS_PER_SECOND / _packetSendPeriod);
@@ -132,6 +132,8 @@ void DefaultCC::onACK(SequenceNumber ackNum) {
     }
     
     setPacketSendPeriod((_packetSendPeriod * synInterval()) / (_packetSendPeriod * increase + synInterval()));
+
+    return false;
 }
 
 void DefaultCC::onLoss(SequenceNumber rangeStart, SequenceNumber rangeEnd) {
@@ -218,7 +220,7 @@ void DefaultCC::stopSlowStart() {
         // If no receiving rate is observed, we have to compute the sending
         // rate according to the current window size, and decrease it
         // using the method below.
-        setPacketSendPeriod(_congestionWindowSize / (_rtt + synInterval()));
+        setPacketSendPeriod(double(_congestionWindowSize) / (_rtt + synInterval()));
     }
 }
 
diff --git a/libraries/networking/src/udt/CongestionControl.h b/libraries/networking/src/udt/CongestionControl.h
index 3ab69efe52..3a93134a5e 100644
--- a/libraries/networking/src/udt/CongestionControl.h
+++ b/libraries/networking/src/udt/CongestionControl.h
@@ -40,9 +40,18 @@ public:
     void setMaxBandwidth(int maxBandwidth);
 
     virtual void init() {}
-    virtual void onACK(SequenceNumber ackNum) {}
+
+    // return value specifies if connection should perform a fast re-transmit of ACK + 1 (used in TCP style congestion control)
+    virtual bool onACK(SequenceNumber ackNum, p_high_resolution_clock::time_point receiveTime) { return false; }
+
     virtual void onLoss(SequenceNumber rangeStart, SequenceNumber rangeEnd) {}
     virtual void onTimeout() {}
+
+    virtual bool shouldNAK() { return true; }
+    virtual bool shouldACK2() { return true; }
+    virtual bool shouldProbe() { return true; }
+
+    virtual void onPacketSent(int wireSize, SequenceNumber seqNum, p_high_resolution_clock::time_point timePoint) {}
 protected:
     void setAckInterval(int ackInterval) { _ackInterval = ackInterval; }
     void setRTO(int rto) { _userDefinedRTO = true; _rto = rto; }
@@ -57,11 +66,11 @@ protected:
     void setPacketSendPeriod(double newSendPeriod); // call this internally to ensure send period doesn't go past max bandwidth
     
     double _packetSendPeriod { 1.0 }; // Packet sending period, in microseconds
-    double _congestionWindowSize { 16.0 }; // Congestion window size, in packets
+    int _congestionWindowSize { 16 }; // Congestion window size, in packets
     
     int _bandwidth { 0 }; // estimated bandwidth, packets per second
     std::atomic<int> _maxBandwidth { -1 }; // Maximum desired bandwidth, bits per second
-    double _maxCongestionWindowSize { 0.0 }; // maximum cwnd size, in packets
+    int _maxCongestionWindowSize { 0 }; // maximum cwnd size, in packets
     
     int _mss { 0 }; // Maximum Packet Size, including all packet headers
     SequenceNumber _sendCurrSeqNum; // current maximum seq num sent out
@@ -102,7 +111,7 @@ public:
     DefaultCC();
     
 public:
-    virtual void onACK(SequenceNumber ackNum) override;
+    virtual bool onACK(SequenceNumber ackNum, p_high_resolution_clock::time_point receiveTime) override;
     virtual void onLoss(SequenceNumber rangeStart, SequenceNumber rangeEnd) override;
     virtual void onTimeout() override;
 
diff --git a/libraries/networking/src/udt/Connection.cpp b/libraries/networking/src/udt/Connection.cpp
index 53cacaeeb4..a190fe3ddc 100644
--- a/libraries/networking/src/udt/Connection.cpp
+++ b/libraries/networking/src/udt/Connection.cpp
@@ -118,12 +118,14 @@ SendQueue& Connection::getSendQueue() {
         QObject::connect(_sendQueue.get(), &SendQueue::queueInactive, this, &Connection::queueInactive);
         QObject::connect(_sendQueue.get(), &SendQueue::timeout, this, &Connection::queueTimeout);
         QObject::connect(_sendQueue.get(), &SendQueue::shortCircuitLoss, this, &Connection::queueShortCircuitLoss);
+
         
         // set defaults on the send queue from our congestion control object and estimatedTimeout()
         _sendQueue->setPacketSendPeriod(_congestionControl->_packetSendPeriod);
         _sendQueue->setSyncInterval(_synInterval);
         _sendQueue->setEstimatedTimeout(estimatedTimeout());
         _sendQueue->setFlowWindowSize(std::min(_flowWindowSize, (int) _congestionControl->_congestionWindowSize));
+        _sendQueue->setProbePacketEnabled(_congestionControl->shouldProbe());
 
         // give the randomized sequence number to the congestion control object
         _congestionControl->setInitialSendSequenceNumber(_sendQueue->getCurrentSequenceNumber());
@@ -150,13 +152,13 @@ void Connection::queueInactive() {
 }
 
 void Connection::queueTimeout() {
-    updateCongestionControlAndSendQueue([this]{
+    updateCongestionControlAndSendQueue([this] {
         _congestionControl->onTimeout();
     });
 }
 
 void Connection::queueShortCircuitLoss(quint32 sequenceNumber) {
-    updateCongestionControlAndSendQueue([this, sequenceNumber]{
+    updateCongestionControlAndSendQueue([this, sequenceNumber] {
         _congestionControl->onLoss(SequenceNumber { sequenceNumber }, SequenceNumber { sequenceNumber });
     });
 }
@@ -223,9 +225,11 @@ void Connection::sync() {
         // reset the number of light ACKs or non SYN ACKs during this sync interval
         _lightACKsDuringSYN = 1;
         _acksDuringSYN = 1;
-        
-        // we send out a periodic ACK every rate control interval
-        sendACK();
+
+        if (_congestionControl->_ackInterval > 1) {
+            // we send out a periodic ACK every rate control interval
+            sendACK();
+        }
         
         if (_lossList.getLength() > 0) {
             // check if we need to re-transmit a loss list
@@ -260,12 +264,17 @@ void Connection::sync() {
     }
 }
 
-void Connection::recordSentPackets(int dataSize, int payloadSize) {
-    _stats.recordSentPackets(payloadSize, dataSize);
+void Connection::recordSentPackets(int wireSize, int payloadSize,
+                                   SequenceNumber seqNum, p_high_resolution_clock::time_point timePoint) {
+    _stats.recordSentPackets(payloadSize, wireSize);
+
+    _congestionControl->onPacketSent(wireSize, seqNum, timePoint);
 }
 
-void Connection::recordRetransmission() {
+void Connection::recordRetransmission(int wireSize, SequenceNumber seqNum, p_high_resolution_clock::time_point timePoint) {
     _stats.record(ConnectionStats::Stats::Retransmission);
+
+    _congestionControl->onPacketSent(wireSize, seqNum, timePoint);
 }
 
 void Connection::sendACK(bool wasCausedBySyncTimeout) {
@@ -308,8 +317,8 @@ void Connection::sendACK(bool wasCausedBySyncTimeout) {
     
     // pack the available buffer size, in packets
     // in our implementation we have no hard limit on receive buffer size, send the default value
-    _ackPacket->writePrimitive((int32_t) udt::CONNECTION_RECEIVE_BUFFER_SIZE_PACKETS);
-    
+    _ackPacket->writePrimitive((int32_t) udt::MAX_PACKETS_IN_FLIGHT);
+
     if (wasCausedBySyncTimeout) {
         // grab the up to date packet receive speed and estimated bandwidth
         int32_t packetReceiveSpeed = _receiveWindow.getPacketReceiveSpeed();
@@ -475,23 +484,24 @@ bool Connection::processReceivedSequenceNumber(SequenceNumber sequenceNumber, in
         } else {
             _lossList.append(_lastReceivedSequenceNumber + 1, sequenceNumber - 1);
         }
-        
-        // Send a NAK packet
-        sendNAK(sequenceNumber);
-        
-        // figure out when we should send the next loss report, if we haven't heard anything back
-        _nakInterval = estimatedTimeout();
-        
-        int receivedPacketsPerSecond = _receiveWindow.getPacketReceiveSpeed();
-        if (receivedPacketsPerSecond > 0) {
-            // the NAK interval is at least the _minNAKInterval
-            // but might be the time required for all lost packets to be retransmitted
-            _nakInterval += (int) (_lossList.getLength() * (USECS_PER_SECOND / receivedPacketsPerSecond));
-        }
-        
-        // the NAK interval is at least the _minNAKInterval but might be the value calculated above, if that is larger
-        _nakInterval = std::max(_nakInterval, _minNAKInterval);
 
+        if (_congestionControl->shouldNAK()) {
+            // Send a NAK packet
+            sendNAK(sequenceNumber);
+
+            // figure out when we should send the next loss report, if we haven't heard anything back
+            _nakInterval = estimatedTimeout();
+
+            int receivedPacketsPerSecond = _receiveWindow.getPacketReceiveSpeed();
+            if (receivedPacketsPerSecond > 0) {
+                // the NAK interval is at least the _minNAKInterval
+                // but might be the time required for all lost packets to be retransmitted
+                _nakInterval += (int) (_lossList.getLength() * (USECS_PER_SECOND / receivedPacketsPerSecond));
+            }
+
+            // the NAK interval is at least the _minNAKInterval but might be the value calculated above, if that is larger
+            _nakInterval = std::max(_nakInterval, _minNAKInterval);
+        }
     }
     
     bool wasDuplicate = false;
@@ -508,7 +518,10 @@ bool Connection::processReceivedSequenceNumber(SequenceNumber sequenceNumber, in
     ++_packetsSinceACK;
     
     // check if we need to send an ACK, according to CC params
-    if (_congestionControl->_ackInterval > 0 && _packetsSinceACK >= _congestionControl->_ackInterval * _acksDuringSYN) {
+    if (_congestionControl->_ackInterval == 1) {
+        // using a congestion control that ACKs every packet (like TCP Vegas)
+        sendACK(true);
+    } else if (_congestionControl->_ackInterval > 0 && _packetsSinceACK >= _congestionControl->_ackInterval * _acksDuringSYN) {
         _acksDuringSYN++;
         sendACK(false);
     } else if (_congestionControl->_lightACKInterval > 0
@@ -598,7 +611,8 @@ void Connection::processACK(ControlPacketPointer controlPacket) {
     
     microseconds sinceLastACK2 = duration_cast<microseconds>(currentTime - lastACK2SendTime);
     
-    if (sinceLastACK2.count() >= _synInterval || currentACKSubSequenceNumber == _lastSentACK2) {
+    if (_congestionControl->shouldACK2()
+        && (sinceLastACK2.count() >= _synInterval || currentACKSubSequenceNumber == _lastSentACK2)) {
         // Send ACK2 packet
         sendACK2(currentACKSubSequenceNumber);
         
@@ -678,8 +692,11 @@ void Connection::processACK(ControlPacketPointer controlPacket) {
     }
     
     // give this ACK to the congestion control and update the send queue parameters
-    updateCongestionControlAndSendQueue([this, ack](){
-        _congestionControl->onACK(ack);
+    updateCongestionControlAndSendQueue([this, ack, &controlPacket] {
+        if (_congestionControl->onACK(ack, controlPacket->getReceiveTime())) {
+            // the congestion control has told us it needs a fast re-transmit of ack + 1, add that now
+            _sendQueue->fastRetransmit(ack + 1);
+        }
     });
     
     _stats.record(ConnectionStats::Stats::ProcessedACK);
@@ -764,7 +781,7 @@ void Connection::processNAK(ControlPacketPointer controlPacket) {
     getSendQueue().nak(start, end);
     
     // give the loss to the congestion control object and update the send queue parameters
-    updateCongestionControlAndSendQueue([this, start, end](){
+    updateCongestionControlAndSendQueue([this, start, end] {
         _congestionControl->onLoss(start, end);
     });
     
diff --git a/libraries/networking/src/udt/Connection.h b/libraries/networking/src/udt/Connection.h
index a18a23f160..f94550426e 100644
--- a/libraries/networking/src/udt/Connection.h
+++ b/libraries/networking/src/udt/Connection.h
@@ -87,8 +87,8 @@ signals:
     void receiverHandshakeRequestComplete(const HifiSockAddr& sockAddr);
 
 private slots:
-    void recordSentPackets(int payload, int total);
-    void recordRetransmission();
+    void recordSentPackets(int wireSize, int payloadSize, SequenceNumber seqNum, p_high_resolution_clock::time_point timePoint);
+    void recordRetransmission(int wireSize, SequenceNumber sequenceNumber, p_high_resolution_clock::time_point timePoint);
     void queueInactive();
     void queueTimeout();
     void queueShortCircuitLoss(quint32 sequenceNumber);
diff --git a/libraries/networking/src/udt/Constants.h b/libraries/networking/src/udt/Constants.h
index 3186571f9b..243fa4edda 100644
--- a/libraries/networking/src/udt/Constants.h
+++ b/libraries/networking/src/udt/Constants.h
@@ -17,6 +17,7 @@
 #include "SequenceNumber.h"
 
 namespace udt {
+
     static const int UDP_IPV4_HEADER_SIZE = 28;
     static const int MAX_PACKET_SIZE_WITH_UDP_HEADER = 1492;
     static const int MAX_PACKET_SIZE = MAX_PACKET_SIZE_WITH_UDP_HEADER - UDP_IPV4_HEADER_SIZE;
diff --git a/libraries/networking/src/udt/PacketHeaders.cpp b/libraries/networking/src/udt/PacketHeaders.cpp
index ec4e724c1b..7e788ce02b 100644
--- a/libraries/networking/src/udt/PacketHeaders.cpp
+++ b/libraries/networking/src/udt/PacketHeaders.cpp
@@ -58,8 +58,7 @@ PacketVersion versionForPacketType(PacketType packetType) {
         case PacketType::AssetGetInfo:
         case PacketType::AssetGet:
         case PacketType::AssetUpload:
-            // Removal of extension from Asset requests
-            return 18;
+            return static_cast<PacketVersion>(AssetServerPacketVersion::VegasCongestionControl);
         case PacketType::NodeIgnoreRequest:
             return 18; // Introduction of node ignore request (which replaced an unused packet tpye)
 
diff --git a/libraries/networking/src/udt/PacketHeaders.h b/libraries/networking/src/udt/PacketHeaders.h
index aa775b9f53..844847e791 100644
--- a/libraries/networking/src/udt/PacketHeaders.h
+++ b/libraries/networking/src/udt/PacketHeaders.h
@@ -189,6 +189,10 @@ const PacketVersion VERSION_MODEL_ENTITIES_SUPPORT_SIMPLE_HULLS = 62;
 const PacketVersion VERSION_WEB_ENTITIES_SUPPORT_DPI = 63;
 const PacketVersion VERSION_ENTITIES_ARROW_ACTION = 64;
 
+enum class AssetServerPacketVersion: PacketVersion {
+    VegasCongestionControl = 19
+};
+
 enum class AvatarMixerPacketVersion : PacketVersion {
     TranslationSupport = 17,
     SoftAttachmentSupport,
diff --git a/libraries/networking/src/udt/SendQueue.cpp b/libraries/networking/src/udt/SendQueue.cpp
index 65619e2b50..f42e2b77fb 100644
--- a/libraries/networking/src/udt/SendQueue.cpp
+++ b/libraries/networking/src/udt/SendQueue.cpp
@@ -180,6 +180,16 @@ void SendQueue::nak(SequenceNumber start, SequenceNumber end) {
     _emptyCondition.notify_one();
 }
 
+void SendQueue::fastRetransmit(udt::SequenceNumber ack) {
+    {
+        std::lock_guard<std::mutex> nakLocker(_naksLock);
+        _naks.insert(ack, ack);
+    }
+
+    // call notify_one on the condition_variable_any in case the send thread is sleeping waiting for losses to re-send
+    _emptyCondition.notify_one();
+}
+
 void SendQueue::overrideNAKListFromPacket(ControlPacket& packet) {
     // this is a response from the client, re-set our timeout expiry
     _lastReceiverResponse = QDateTime::currentMSecsSinceEpoch();
@@ -242,11 +252,13 @@ bool SendQueue::sendNewPacketAndAddToSentList(std::unique_ptr<Packet> newPacket,
     newPacket->writeSequenceNumber(sequenceNumber);
 
     // Save packet/payload size before we move it
-    auto packetSize = newPacket->getDataSize();
+    auto packetSize = newPacket->getWireSize();
     auto payloadSize = newPacket->getPayloadSize();
     
     auto bytesWritten = sendPacket(*newPacket);
 
+    emit packetSent(packetSize, payloadSize, sequenceNumber, p_high_resolution_clock::now());
+
     {
         // Insert the packet we have just sent in the sent list
         QWriteLocker locker(&_sentLock);
@@ -256,8 +268,6 @@ bool SendQueue::sendNewPacketAndAddToSentList(std::unique_ptr<Packet> newPacket,
     }
     Q_ASSERT_X(!newPacket, "SendQueue::sendNewPacketAndAddToSentList()", "Overriden packet in sent list");
 
-    emit packetSent(packetSize, payloadSize);
-
     if (bytesWritten < 0) {
         // this is a short-circuit loss - we failed to put this packet on the wire
         // so immediately add it to the loss list
@@ -328,60 +338,66 @@ void SendQueue::run() {
             return;
         }
 
-        // push the next packet timestamp forwards by the current packet send period
-        auto nextPacketDelta = (newPacketCount == 2 ? 2 : 1) * _packetSendPeriod;
-        nextPacketTimestamp += std::chrono::microseconds(nextPacketDelta);
+        if (_packetSendPeriod > 0) {
+            // push the next packet timestamp forwards by the current packet send period
+            auto nextPacketDelta = (newPacketCount == 2 ? 2 : 1) * _packetSendPeriod;
+            nextPacketTimestamp += std::chrono::microseconds(nextPacketDelta);
 
-        // sleep as long as we need for next packet send, if we can
-        auto now = p_high_resolution_clock::now();
+            // sleep as long as we need for next packet send, if we can
+            auto now = p_high_resolution_clock::now();
 
-        auto timeToSleep = duration_cast<microseconds>(nextPacketTimestamp - now);
+            auto timeToSleep = duration_cast<microseconds>(nextPacketTimestamp - now);
 
-        // we use nextPacketTimestamp so that we don't fall behind, not to force long sleeps
-        // we'll never allow nextPacketTimestamp to force us to sleep for more than nextPacketDelta
-        // so cap it to that value
-        if (timeToSleep > std::chrono::microseconds(nextPacketDelta)) {
-            // reset the nextPacketTimestamp so that it is correct next time we come around
-            nextPacketTimestamp = now + std::chrono::microseconds(nextPacketDelta);
+            // we use nextPacketTimestamp so that we don't fall behind, not to force long sleeps
+            // we'll never allow nextPacketTimestamp to force us to sleep for more than nextPacketDelta
+            // so cap it to that value
+            if (timeToSleep > std::chrono::microseconds(nextPacketDelta)) {
+                // reset the nextPacketTimestamp so that it is correct next time we come around
+                nextPacketTimestamp = now + std::chrono::microseconds(nextPacketDelta);
 
-            timeToSleep = std::chrono::microseconds(nextPacketDelta);
-        }
+                timeToSleep = std::chrono::microseconds(nextPacketDelta);
+            }
 
-        // we're seeing SendQueues sleep for a long period of time here,
-        // which can lock the NodeList if it's attempting to clear connections
-        // for now we guard this by capping the time this thread and sleep for
+            // we're seeing SendQueues sleep for a long period of time here,
+            // which can lock the NodeList if it's attempting to clear connections
+            // for now we guard this by capping the time this thread and sleep for
 
-        const microseconds MAX_SEND_QUEUE_SLEEP_USECS { 2000000 };
-        if (timeToSleep > MAX_SEND_QUEUE_SLEEP_USECS) {
-            qWarning() << "udt::SendQueue wanted to sleep for" << timeToSleep.count() << "microseconds";
-            qWarning() << "Capping sleep to" << MAX_SEND_QUEUE_SLEEP_USECS.count();
-            qWarning() << "PSP:" << _packetSendPeriod << "NPD:" << nextPacketDelta
+            const microseconds MAX_SEND_QUEUE_SLEEP_USECS { 2000000 };
+            if (timeToSleep > MAX_SEND_QUEUE_SLEEP_USECS) {
+                qWarning() << "udt::SendQueue wanted to sleep for" << timeToSleep.count() << "microseconds";
+                qWarning() << "Capping sleep to" << MAX_SEND_QUEUE_SLEEP_USECS.count();
+                qWarning() << "PSP:" << _packetSendPeriod << "NPD:" << nextPacketDelta
                 << "NPT:" << nextPacketTimestamp.time_since_epoch().count()
                 << "NOW:" << now.time_since_epoch().count();
 
-            // alright, we're in a weird state
-            // we want to know why this is happening so we can implement a better fix than this guard
-            // send some details up to the API (if the user allows us) that indicate how we could such a large timeToSleep
-            static const QString SEND_QUEUE_LONG_SLEEP_ACTION = "sendqueue-sleep";
+                // alright, we're in a weird state
+                // we want to know why this is happening so we can implement a better fix than this guard
+                // send some details up to the API (if the user allows us) that indicate how we could such a large timeToSleep
+                static const QString SEND_QUEUE_LONG_SLEEP_ACTION = "sendqueue-sleep";
 
-            // setup a json object with the details we want
-            QJsonObject longSleepObject;
-            longSleepObject["timeToSleep"] = qint64(timeToSleep.count());
-            longSleepObject["packetSendPeriod"] = _packetSendPeriod.load();
-            longSleepObject["nextPacketDelta"] = nextPacketDelta;
-            longSleepObject["nextPacketTimestamp"] = qint64(nextPacketTimestamp.time_since_epoch().count());
-            longSleepObject["then"] = qint64(now.time_since_epoch().count());
+                // setup a json object with the details we want
+                QJsonObject longSleepObject;
+                longSleepObject["timeToSleep"] = qint64(timeToSleep.count());
+                longSleepObject["packetSendPeriod"] = _packetSendPeriod.load();
+                longSleepObject["nextPacketDelta"] = nextPacketDelta;
+                longSleepObject["nextPacketTimestamp"] = qint64(nextPacketTimestamp.time_since_epoch().count());
+                longSleepObject["then"] = qint64(now.time_since_epoch().count());
 
-            // hopefully send this event using the user activity logger
-            UserActivityLogger::getInstance().logAction(SEND_QUEUE_LONG_SLEEP_ACTION, longSleepObject);
-
-            timeToSleep = MAX_SEND_QUEUE_SLEEP_USECS;
+                // hopefully send this event using the user activity logger
+                UserActivityLogger::getInstance().logAction(SEND_QUEUE_LONG_SLEEP_ACTION, longSleepObject);
+                
+                timeToSleep = MAX_SEND_QUEUE_SLEEP_USECS;
+            }
+            
+            std::this_thread::sleep_for(timeToSleep);
         }
-
-        std::this_thread::sleep_for(timeToSleep);
     }
 }
 
+void SendQueue::setProbePacketEnabled(bool enabled) {
+    _shouldSendProbes = enabled;
+}
+
 int SendQueue::maybeSendNewPacket() {
     if (!isFlowWindowFull()) {
         // we didn't re-send a packet, so time to send a new one
@@ -399,7 +415,7 @@ int SendQueue::maybeSendNewPacket() {
                 std::unique_ptr<Packet> secondPacket;
                 bool shouldSendPairTail = false;
 
-                if (((uint32_t) nextNumber & 0xF) == 0) {
+                if (_shouldSendProbes && ((uint32_t) nextNumber & 0xF) == 0) {
                     // the first packet is the first in a probe pair - every 16 (rightmost 16 bits = 0) packets
                     // pull off a second packet if we can before we unlock
                     shouldSendPairTail = true;
@@ -492,7 +508,7 @@ bool SendQueue::maybeResendPacket() {
                     sentLocker.unlock();
                 }
                 
-                emit packetRetransmitted();
+                emit packetRetransmitted(resendPacket.getWireSize(), it->first, p_high_resolution_clock::now());
                 
                 // Signal that we did resend a packet
                 return true;
diff --git a/libraries/networking/src/udt/SendQueue.h b/libraries/networking/src/udt/SendQueue.h
index 21f6141c3c..6e17c5b9c6 100644
--- a/libraries/networking/src/udt/SendQueue.h
+++ b/libraries/networking/src/udt/SendQueue.h
@@ -64,18 +64,21 @@ public:
     
     void setEstimatedTimeout(int estimatedTimeout) { _estimatedTimeout = estimatedTimeout; }
     void setSyncInterval(int syncInterval) { _syncInterval = syncInterval; }
+
+    void setProbePacketEnabled(bool enabled);
     
 public slots:
     void stop();
     
     void ack(SequenceNumber ack);
     void nak(SequenceNumber start, SequenceNumber end);
+    void fastRetransmit(SequenceNumber ack);
     void overrideNAKListFromPacket(ControlPacket& packet);
     void handshakeACK(SequenceNumber initialSequenceNumber);
 
 signals:
-    void packetSent(int dataSize, int payloadSize);
-    void packetRetransmitted();
+    void packetSent(int wireSize, int payloadSize, SequenceNumber seqNum, p_high_resolution_clock::time_point timePoint);
+    void packetRetransmitted(int wireSize, SequenceNumber seqNum, p_high_resolution_clock::time_point timePoint);
     
     void queueInactive();
 
@@ -139,6 +142,9 @@ private:
     std::condition_variable _handshakeACKCondition;
     
     std::condition_variable_any _emptyCondition;
+
+
+    std::atomic<bool> _shouldSendProbes { true };
 };
     
 }
diff --git a/libraries/networking/src/udt/SequenceNumber.cpp b/libraries/networking/src/udt/SequenceNumber.cpp
index 3e94c35d44..a518beb172 100644
--- a/libraries/networking/src/udt/SequenceNumber.cpp
+++ b/libraries/networking/src/udt/SequenceNumber.cpp
@@ -11,6 +11,14 @@
 
 #include "SequenceNumber.h"
 
+#include <QtCore/QMetaType>
+
+using namespace udt;
+
+Q_DECLARE_METATYPE(SequenceNumber);
+
+static const int sequenceNumberMetaTypeID = qRegisterMetaType<SequenceNumber>();
+
 int udt::seqlen(const SequenceNumber& seq1, const SequenceNumber& seq2) {
     return (seq1._value <= seq2._value) ? (seq2._value - seq1._value + 1)
                                         : (seq2._value - seq1._value + SequenceNumber::MAX + 2);
diff --git a/libraries/networking/src/udt/Socket.cpp b/libraries/networking/src/udt/Socket.cpp
index 03a32a5fe3..16a1bd1639 100644
--- a/libraries/networking/src/udt/Socket.cpp
+++ b/libraries/networking/src/udt/Socket.cpp
@@ -289,6 +289,9 @@ void Socket::messageFailed(Connection* connection, Packet::MessageNumber message
 void Socket::readPendingDatagrams() {
     int packetSizeWithHeader = -1;
     while ((packetSizeWithHeader = _udpSocket.pendingDatagramSize()) != -1) {
+        // grab a time point we can mark as the receive time of this packet
+        auto receiveTime = p_high_resolution_clock::now();
+        
         // setup a HifiSockAddr to read into
         HifiSockAddr senderSockAddr;
 
@@ -311,6 +314,7 @@ void Socket::readPendingDatagrams() {
             // we have a registered unfiltered handler for this HifiSockAddr - call that and return
             if (it->second) {
                 auto basePacket = BasePacket::fromReceivedPacket(std::move(buffer), packetSizeWithHeader, senderSockAddr);
+                basePacket->setReceiveTime(receiveTime);
                 it->second(std::move(basePacket));
             }
 
@@ -323,6 +327,7 @@ void Socket::readPendingDatagrams() {
         if (isControlPacket) {
             // setup a control packet from the data we just read
             auto controlPacket = ControlPacket::fromReceivedPacket(std::move(buffer), packetSizeWithHeader, senderSockAddr);
+            controlPacket->setReceiveTime(receiveTime);
 
             // move this control packet to the matching connection, if there is one
             auto connection = findOrCreateConnection(senderSockAddr);
@@ -334,6 +339,7 @@ void Socket::readPendingDatagrams() {
         } else {
             // setup a Packet from the data we just read
             auto packet = Packet::fromReceivedPacket(std::move(buffer), packetSizeWithHeader, senderSockAddr);
+            packet->setReceiveTime(receiveTime);
 
             // call our verification operator to see if this packet is verified
             if (!_packetFilterOperator || _packetFilterOperator(*packet)) {
diff --git a/libraries/networking/src/udt/Socket.h b/libraries/networking/src/udt/Socket.h
index 59c3ec9cde..cced0c53df 100644
--- a/libraries/networking/src/udt/Socket.h
+++ b/libraries/networking/src/udt/Socket.h
@@ -22,7 +22,7 @@
 #include <QtNetwork/QUdpSocket>
 
 #include "../HifiSockAddr.h"
-#include "CongestionControl.h"
+#include "TCPVegasCC.h"
 #include "Connection.h"
 
 //#define UDT_CONNECTION_DEBUG
@@ -130,8 +130,8 @@ private:
     QTimer* _synTimer { nullptr };
 
     int _maxBandwidth { -1 };
-    
-    std::unique_ptr<CongestionControlVirtualFactory> _ccFactory { new CongestionControlFactory<DefaultCC>() };
+
+    std::unique_ptr<CongestionControlVirtualFactory> _ccFactory { new CongestionControlFactory<TCPVegasCC>() };
     
     friend UDTTest;
 };
diff --git a/libraries/networking/src/udt/TCPVegasCC.cpp b/libraries/networking/src/udt/TCPVegasCC.cpp
new file mode 100644
index 0000000000..5738ea8421
--- /dev/null
+++ b/libraries/networking/src/udt/TCPVegasCC.cpp
@@ -0,0 +1,282 @@
+//
+//  TCPVegasCC.cpp
+//  libraries/networking/src/udt
+//
+//  Created by Stephen Birarda on 2016-09-20.
+//  Copyright 2016 High Fidelity, Inc.
+//
+//  Distributed under the Apache License, Version 2.0.
+//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
+//
+
+#include "TCPVegasCC.h"
+
+#include <QtCore/QDebug>
+#include <QtCore/QtGlobal>
+
+using namespace udt;
+using namespace std::chrono;
+
+TCPVegasCC::TCPVegasCC() {
+    _packetSendPeriod = 0.0;
+    _congestionWindowSize = 2;
+
+    setAckInterval(1); // TCP sends an ACK for every packet received
+
+    // set our minimum RTT variables to the maximum possible value
+    // we can't do this as a member initializer until our VS has support for constexpr
+    _currentMinRTT = std::numeric_limits<int>::max();
+    _baseRTT = std::numeric_limits<int>::max();
+}
+
+bool TCPVegasCC::onACK(SequenceNumber ack, p_high_resolution_clock::time_point receiveTime) {
+    auto it = _sentPacketTimes.find(ack);
+
+    auto previousAck = _lastACK;
+    _lastACK = ack;
+
+    if (it != _sentPacketTimes.end()) {
+
+        // calculate the RTT (receive time - time ACK sent)
+        int lastRTT = duration_cast<microseconds>(receiveTime - it->second).count();
+
+        const int MAX_RTT_SAMPLE_MICROSECONDS = 10000000;
+
+        if (lastRTT < 0) {
+            Q_ASSERT_X(false, __FUNCTION__, "calculated an RTT that is not > 0");
+            return false;
+        } else if (lastRTT == 0) {
+            // we do not allow a zero microsecond RTT (as per the UNIX kernel implementation of TCP Vegas)
+            lastRTT = 1;
+        } else if (lastRTT > MAX_RTT_SAMPLE_MICROSECONDS) {
+            // we cap the lastRTT to MAX_RTT_SAMPLE_MICROSECONDS to avoid overflows in window size calculations
+            lastRTT = MAX_RTT_SAMPLE_MICROSECONDS;
+        }
+
+        if (_ewmaRTT == -1) {
+            // first RTT sample - set _ewmaRTT to the value and set the variance to half the value
+            _ewmaRTT = lastRTT;
+            _rttVariance = lastRTT / 2;
+        } else {
+            // This updates the RTT using exponential weighted moving average
+            // This is the Jacobson's forumla for RTT estimation
+            // http://www.mathcs.emory.edu/~cheung/Courses/455/Syllabus/7-transport/Jacobson-88.pdf
+
+            // Estimated RTT = (1 - x)(estimatedRTT) + (x)(sampleRTT)
+            // (where x = 0.125 via Jacobson)
+
+            // Deviation  = (1 - x)(deviation) + x |sampleRTT - estimatedRTT|
+            // (where x = 0.25 via Jacobson)
+
+            static const int RTT_ESTIMATION_ALPHA = 8;
+            static const int RTT_ESTIMATION_VARIANCE_ALPHA = 4;
+
+            _ewmaRTT = (_ewmaRTT * (RTT_ESTIMATION_ALPHA - 1) + lastRTT) / RTT_ESTIMATION_ALPHA;
+            _rttVariance = (_rttVariance * (RTT_ESTIMATION_VARIANCE_ALPHA- 1)
+                            + abs(lastRTT - _ewmaRTT)) / RTT_ESTIMATION_VARIANCE_ALPHA;
+        }
+
+        // add 1 to the number of ACKs during this RTT
+        ++_numACKs;
+
+        // keep track of the lowest RTT during connection
+        _baseRTT = std::min(_baseRTT, lastRTT);
+
+        // find the min RTT during the last RTT
+        _currentMinRTT = std::min(_currentMinRTT, lastRTT);
+
+        auto sinceLastAdjustment = duration_cast<microseconds>(p_high_resolution_clock::now() - _lastAdjustmentTime).count();
+        if (sinceLastAdjustment >= _ewmaRTT) {
+            performCongestionAvoidance(ack);
+        }
+
+        // remove this sent packet time from the hash
+        _sentPacketTimes.erase(it);
+    }
+
+    ++_numACKSinceFastRetransmit;
+
+    // perform the fast re-transmit check if this is a duplicate ACK or if this is the first or second ACK
+    // after a previous fast re-transmit
+    if (ack == previousAck || _numACKSinceFastRetransmit < 3) {
+        // we may need to re-send ackNum + 1 if it has been more than our estimated timeout since it was sent
+
+        auto it = _sentPacketTimes.find(ack + 1);
+        if (it != _sentPacketTimes.end()) {
+            auto estimatedTimeout = _ewmaRTT + _rttVariance * 4;
+
+            auto now = p_high_resolution_clock::now();
+            auto sinceSend = duration_cast<microseconds>(now - it->second).count();
+
+            if (sinceSend >= estimatedTimeout) {
+                // break out of slow start, we've decided this is loss
+                _slowStart = false;
+
+                // reset the fast re-transmit counter
+                _numACKSinceFastRetransmit = 0;
+
+                // return true so the caller knows we needed a fast re-transmit
+                return true;
+            }
+        }
+
+        // if this is the 3rd duplicate ACK, we fallback to Reno's fast re-transmit
+        static const int RENO_FAST_RETRANSMIT_DUPLICATE_COUNT = 3;
+
+        ++_duplicateACKCount;
+
+        if (ack == previousAck &&  _duplicateACKCount == RENO_FAST_RETRANSMIT_DUPLICATE_COUNT) {
+            // break out of slow start, we just hit loss
+            _slowStart = false;
+
+            // reset our fast re-transmit counters
+            _numACKSinceFastRetransmit = 0;
+            _duplicateACKCount = 0;
+
+            // return true so the caller knows we needed a fast re-transmit
+            return true;
+        }
+    } else {
+        _duplicateACKCount = 0;
+    }
+
+    // ACK processed, no fast re-transmit required
+    return false;
+}
+
+void TCPVegasCC::performCongestionAvoidance(udt::SequenceNumber ack) {
+    static int VEGAS_ALPHA_SEGMENTS = 4;
+    static int VEGAS_BETA_SEGMENTS = 6;
+    static int VEGAS_GAMMA_SEGMENTS = 1;
+
+    // http://pages.cs.wisc.edu/~akella/CS740/S08/740-Papers/BOP94.pdf
+    // Use the Vegas algorithm to see if we should
+    // increase or decrease the congestion window size, and by how much
+
+    // Grab the minimum RTT seen during the last RTT (since the last performed congestion avoidance)
+    
+    // Taking the min avoids the effects of delayed ACKs
+    // (though congestion may be noticed a bit later)
+    int rtt = _currentMinRTT;
+
+    int64_t windowSizeDiff = (int64_t) _congestionWindowSize * (rtt - _baseRTT) / _baseRTT;
+
+    if (_numACKs <= 2) {
+        performRenoCongestionAvoidance(ack);
+    } else {
+        if (_slowStart) {
+            if (windowSizeDiff > VEGAS_GAMMA_SEGMENTS) {
+                // we're going too fast - this breaks us out of slow start and we switch to linear increase/decrease
+                _slowStart = false;
+
+                int expectedWindowSize = _congestionWindowSize * _baseRTT / rtt;
+                _baseRTT = std::numeric_limits<int>::max();
+
+                // drop the congestion window size to the expected size, if smaller
+                _congestionWindowSize = std::min(_congestionWindowSize, expectedWindowSize + 1);
+
+            } else if (++_slowStartOddAdjust & 1) {
+                // we're in slow start and not going too fast
+                // this means that once every second RTT we perform exponential congestion window growth
+                _congestionWindowSize *= 2;
+            }
+        } else {
+            // this is the normal linear increase/decrease of the Vegas algorithm
+            // to figure out where the congestion window should be
+            if (windowSizeDiff > VEGAS_BETA_SEGMENTS) {
+                // the old congestion window was too fast (difference > beta)
+                // so reduce it to slow down
+                --_congestionWindowSize;
+
+            } else if (windowSizeDiff < VEGAS_ALPHA_SEGMENTS) {
+                // there aren't enough packets on the wire, add more to the congestion window
+                ++_congestionWindowSize;
+            } else {
+                // sending rate seems good, no congestion window adjustment
+            }
+        }
+    }
+
+    // we never allow the congestion window to be smaller than two packets
+    static int VEGAS_CW_MIN_PACKETS = 2;
+    if (_congestionWindowSize < VEGAS_CW_MIN_PACKETS) {
+        _congestionWindowSize = VEGAS_CW_MIN_PACKETS;
+    } else if (_congestionWindowSize > udt::MAX_PACKETS_IN_FLIGHT) {
+        _congestionWindowSize = udt::MAX_PACKETS_IN_FLIGHT;
+    }
+
+    // mark this as the last adjustment time
+    _lastAdjustmentTime = p_high_resolution_clock::now();
+
+    // reset our state for the next RTT
+    _currentMinRTT = std::numeric_limits<int>::max();
+
+    // reset our count of collected RTT samples
+    _numACKs = 0;
+}
+
+bool TCPVegasCC::isCongestionWindowLimited() {
+    if (_slowStart) {
+        return true;
+    } else {
+        return seqlen(_sendCurrSeqNum, _lastACK) < _congestionWindowSize;
+    }
+}
+
+void TCPVegasCC::performRenoCongestionAvoidance(SequenceNumber ack) {
+    if (!isCongestionWindowLimited()) {
+        return;
+    }
+
+    int numAcked = _numACKs;
+
+    if (_slowStart) {
+        // while in slow start we grow the congestion window by the number of ACKed packets
+        // allowing it to grow as high as the slow start threshold
+        int congestionWindow = _congestionWindowSize + numAcked;
+
+        if (congestionWindow > udt::MAX_PACKETS_IN_FLIGHT) {
+            // we're done with slow start, set the congestion window to the slow start threshold
+            _congestionWindowSize = udt::MAX_PACKETS_IN_FLIGHT;
+
+            // figure out how many left over ACKs we should apply using the regular reno congestion avoidance
+            numAcked = congestionWindow - udt::MAX_PACKETS_IN_FLIGHT;
+        } else {
+            _congestionWindowSize = congestionWindow;
+            numAcked = 0;
+        }
+    }
+
+    // grab the size of the window prior to reno additive increase
+    int preAIWindowSize = _congestionWindowSize;
+
+    if (numAcked > 0) {
+        // Once we are out of slow start, we use additive increase to grow the window slowly.
+        // We grow the congestion window by a single packet everytime the entire congestion window is sent.
+
+        // If credits accumulated at a higher preAIWindowSize, apply them gently now.
+        if (_ackAICount >= preAIWindowSize) {
+            _ackAICount = 0;
+            ++_congestionWindowSize;
+        }
+
+        // increase the window size by (1 / window size) for every ACK received
+        _ackAICount += numAcked;
+        if (_ackAICount >= preAIWindowSize) {
+            // when _ackAICount % preAIWindowSize == 0 then _ackAICount is 0
+            // when _ackAICount % preAIWindowSize != 0 then _ackAICount is _ackAICount - (_ackAICount % preAIWindowSize)
+
+            int delta = _ackAICount / preAIWindowSize;
+
+            _ackAICount -= delta * preAIWindowSize;
+            _congestionWindowSize += delta;
+        }
+    }
+}
+
+void TCPVegasCC::onPacketSent(int wireSize, SequenceNumber seqNum, p_high_resolution_clock::time_point timePoint) {
+    if (_sentPacketTimes.find(seqNum) == _sentPacketTimes.end()) {
+        _sentPacketTimes[seqNum] = timePoint;
+    }
+}
+
diff --git a/libraries/networking/src/udt/TCPVegasCC.h b/libraries/networking/src/udt/TCPVegasCC.h
new file mode 100644
index 0000000000..862ea36d8f
--- /dev/null
+++ b/libraries/networking/src/udt/TCPVegasCC.h
@@ -0,0 +1,77 @@
+//
+//  TCPVegasCC.h
+//  libraries/networking/src/udt
+//
+//  Created by Stephen Birarda on 2016-09-20.
+//  Copyright 2016 High Fidelity, Inc.
+//
+//  Distributed under the Apache License, Version 2.0.
+//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
+//
+
+#pragma once
+
+#ifndef hifi_TCPVegasCC_h
+#define hifi_TCPVegasCC_h
+
+#include <map>
+
+#include "CongestionControl.h"
+#include "Constants.h"
+
+namespace udt {
+    
+
+class TCPVegasCC : public CongestionControl {
+public:
+    TCPVegasCC();
+
+    virtual bool onACK(SequenceNumber ackNum, p_high_resolution_clock::time_point receiveTime) override;
+    virtual void onLoss(SequenceNumber rangeStart, SequenceNumber rangeEnd) override {};
+    virtual void onTimeout() override {};
+
+    virtual bool shouldNAK() override { return false; }
+    virtual bool shouldACK2() override { return false; }
+    virtual bool shouldProbe() override { return false; }
+
+    virtual void onPacketSent(int wireSize, SequenceNumber seqNum, p_high_resolution_clock::time_point timePoint) override;
+    
+protected:
+    virtual void performCongestionAvoidance(SequenceNumber ack);
+    virtual void setInitialSendSequenceNumber(SequenceNumber seqNum) override { _lastACK = seqNum - 1; }
+private:
+    bool isCongestionWindowLimited();
+    void performRenoCongestionAvoidance(SequenceNumber ack);
+
+    using PacketTimeList = std::map<SequenceNumber, p_high_resolution_clock::time_point>;
+    PacketTimeList _sentPacketTimes; // Map of sequence numbers to sent time
+
+    p_high_resolution_clock::time_point _lastAdjustmentTime; // Time of last congestion control adjustment
+
+    bool _slowStart { true }; // Marker for slow start phase
+
+    SequenceNumber _lastACK; // Sequence number of last packet that was ACKed
+
+    int _numACKSinceFastRetransmit { 3 }; // Number of ACKs received since fast re-transmit, default avoids immediate re-transmit
+
+    int _currentMinRTT; // Current min RTT during last RTT (since last congestion avoidance check), in microseconds
+    int _baseRTT; // Lowest RTT during connection, in microseconds
+    int _ewmaRTT { -1 }; // Exponential weighted moving average RTT
+    int _rttVariance { 0 }; // Variance in collected RTT values
+
+    int _numACKs { 0 }; // Number of ACKs received during the last RTT (since last performed congestion avoidance)
+
+    int _ackAICount { 0 }; // Counter for number of ACKs received for Reno additive increase
+    int _duplicateACKCount { 0 }; // Counter for duplicate ACKs received
+
+    int _slowStartOddAdjust { 0 }; // Marker for every window adjustment every other RTT in slow-start
+
+};
+
+}
+
+
+
+
+
+#endif // hifi_TCPVegasCC_h
diff --git a/libraries/script-engine/src/BatchLoader.cpp b/libraries/script-engine/src/BatchLoader.cpp
index 692c0ecd7a..605d7e95bd 100644
--- a/libraries/script-engine/src/BatchLoader.cpp
+++ b/libraries/script-engine/src/BatchLoader.cpp
@@ -38,6 +38,12 @@ void BatchLoader::start() {
 
     _started = true;
 
+    if (_urls.size() == 0) {
+        _finished = true;
+        emit finished(_data);
+        return;
+    }
+
     for (const auto& rawURL : _urls) {
         QUrl url = expandScriptUrl(normalizeScriptURL(rawURL));
 
diff --git a/libraries/script-engine/src/ScriptEngine.cpp b/libraries/script-engine/src/ScriptEngine.cpp
index 7a4265829b..a9e1defabe 100644
--- a/libraries/script-engine/src/ScriptEngine.cpp
+++ b/libraries/script-engine/src/ScriptEngine.cpp
@@ -1199,6 +1199,11 @@ void ScriptEngine::include(const QStringList& includeFiles, QScriptValue callbac
         }
     }
 
+    // If there are no URLs left to download, don't bother attempting to download anything and return early
+    if (urls.size() == 0) {
+        return;
+    }
+
     BatchLoader* loader = new BatchLoader(urls);
     EntityItemID capturedEntityIdentifier = currentEntityIdentifier;
     QUrl capturedSandboxURL = currentSandboxURL;
diff --git a/libraries/script-engine/src/XMLHttpRequestClass.cpp b/libraries/script-engine/src/XMLHttpRequestClass.cpp
index 818521ecc5..4e528ec52c 100644
--- a/libraries/script-engine/src/XMLHttpRequestClass.cpp
+++ b/libraries/script-engine/src/XMLHttpRequestClass.cpp
@@ -143,13 +143,13 @@ void XMLHttpRequestClass::open(const QString& method, const QString& url, bool a
         if (url.toLower().left(METAVERSE_API_URL.length()) == METAVERSE_API_URL) {
             auto accountManager = DependencyManager::get<AccountManager>();
                 
-            if (accountManager->hasValidAccessToken()) {
-                QUrlQuery urlQuery(_url.query());
-                urlQuery.addQueryItem("access_token", accountManager->getAccountInfo().getAccessToken().token);
-                _url.setQuery(urlQuery);
+            if (_url.scheme() == "https" && accountManager->hasValidAccessToken()) {
+                static const QString HTTP_AUTHORIZATION_HEADER = "Authorization";
+                QString bearerString = "Bearer " + accountManager->getAccountInfo().getAccessToken().token;
+                _request.setRawHeader(HTTP_AUTHORIZATION_HEADER.toLocal8Bit(), bearerString.toLocal8Bit());
             }
-                
         }
+
         if (!username.isEmpty()) {
             _url.setUserName(username);
         }
diff --git a/libraries/shared/src/PortableHighResolutionClock.h b/libraries/shared/src/PortableHighResolutionClock.h
index ec1b068e66..383c6cdf3e 100644
--- a/libraries/shared/src/PortableHighResolutionClock.h
+++ b/libraries/shared/src/PortableHighResolutionClock.h
@@ -21,6 +21,8 @@
 
 #include <chrono>
 
+#include <QtCore/QMetaType>
+
 #if defined(_MSC_VER) && _MSC_VER < 1900
 
 #define WIN32_LEAN_AND_MEAN
@@ -47,5 +49,8 @@ using p_high_resolution_clock = std::chrono::high_resolution_clock;
 
 #endif
 
+Q_DECLARE_METATYPE(p_high_resolution_clock::time_point);
+
+static const int timePointMetaTypeID = qRegisterMetaType<p_high_resolution_clock::time_point>();
 
 #endif // hifi_PortableHighResolutionClock_h
diff --git a/libraries/ui/src/QmlWebWindowClass.cpp b/libraries/ui/src/QmlWebWindowClass.cpp
index 84d0aa0489..2130e84220 100644
--- a/libraries/ui/src/QmlWebWindowClass.cpp
+++ b/libraries/ui/src/QmlWebWindowClass.cpp
@@ -86,13 +86,10 @@ QString QmlWebWindowClass::getURL() const {
     return result.toString();
 }
 
-// HACK find a good place to declare and store this
-extern QString fixupHifiUrl(const QString& urlString);
-
 void QmlWebWindowClass::setURL(const QString& urlString) {
     DependencyManager::get<OffscreenUi>()->executeOnUiThread([=] {
         if (!_qmlWindow.isNull()) {
-            _qmlWindow->setProperty(URL_PROPERTY, fixupHifiUrl(urlString));
+            _qmlWindow->setProperty(URL_PROPERTY, urlString);
         }
     });
 }
diff --git a/libraries/ui/src/QmlWebWindowClass.h b/libraries/ui/src/QmlWebWindowClass.h
index e32c6d5a04..731afb3acb 100644
--- a/libraries/ui/src/QmlWebWindowClass.h
+++ b/libraries/ui/src/QmlWebWindowClass.h
@@ -19,7 +19,7 @@ class QmlWebWindowClass : public QmlWindowClass {
 public:
     static QScriptValue constructor(QScriptContext* context, QScriptEngine* engine);
 
-    public slots:
+public slots:
     QString getURL() const;
     void setURL(const QString& url);
 
diff --git a/scripts/system/controllers/handControllerGrab.js b/scripts/system/controllers/handControllerGrab.js
index e2a982b308..bc7c77a286 100644
--- a/scripts/system/controllers/handControllerGrab.js
+++ b/scripts/system/controllers/handControllerGrab.js
@@ -2091,12 +2091,12 @@ function MyController(hand) {
                 var TEAR_AWAY_DISTANCE = 0.1;
                 var dist = distanceBetweenPointAndEntityBoundingBox(handPosition, props);
                 if (dist > TEAR_AWAY_DISTANCE) {
-                    this.autoUnequipCounter += 1;
+                    this.autoUnequipCounter += deltaTime;
                 } else {
                     this.autoUnequipCounter = 0;
                 }
 
-                if (this.autoUnequipCounter > 1) {
+                if (this.autoUnequipCounter > 0.25) {
                         // for whatever reason, the held/equipped entity has been pulled away.  ungrab or unequip.
                     print("handControllerGrab -- autoreleasing held or equipped item because it is far from hand." +
                         props.parentID + ", dist = " + dist);
diff --git a/tests/render-perf/src/main.cpp b/tests/render-perf/src/main.cpp
index 8abb9f54e5..3df36c0edf 100644
--- a/tests/render-perf/src/main.cpp
+++ b/tests/render-perf/src/main.cpp
@@ -18,10 +18,12 @@
 #include <QtCore/QElapsedTimer>
 #include <QtCore/QLoggingCategory>
 #include <QtCore/QRegularExpression>
+#include <QtCore/QSettings>
 #include <QtCore/QTimer>
 #include <QtCore/QThread>
 #include <QtCore/QThreadPool>
 
+
 #include <QtGui/QGuiApplication>
 #include <QtGui/QResizeEvent>
 #include <QtGui/QWindow>
diff --git a/tools/udt-test/src/UDTTest.cpp b/tools/udt-test/src/UDTTest.cpp
index af94d2294b..6161dbfdbc 100644
--- a/tools/udt-test/src/UDTTest.cpp
+++ b/tools/udt-test/src/UDTTest.cpp
@@ -25,7 +25,7 @@ const QCommandLineOption TARGET_OPTION {
     "IP:PORT or HOSTNAME:PORT"
 };
 const QCommandLineOption PACKET_SIZE {
-    "packet-size", "size for sent packets in bytes (defaults to " + QString(MAX_PACKET_SIZE) + ")", "bytes",
+    "packet-size", "size for sent packets in bytes (defaults to " + QString::number(udt::MAX_PACKET_SIZE) + ")", "bytes",
     QString(udt::MAX_PACKET_SIZE)
 };
 const QCommandLineOption MIN_PACKET_SIZE {