diff --git a/OpenSim/Region/ClientStack/Linden/UDP/LLUDPClient.cs b/OpenSim/Region/ClientStack/Linden/UDP/LLUDPClient.cs
index 2f363f4d2e..c34bafa9b2 100644
--- a/OpenSim/Region/ClientStack/Linden/UDP/LLUDPClient.cs
+++ b/OpenSim/Region/ClientStack/Linden/UDP/LLUDPClient.cs
@@ -650,8 +650,15 @@ namespace OpenSim.Region.ClientStack.LindenUDP
 
                 if (HasUpdates(m_categories))
                 {
-                    // Asynchronously run the callback
-                    Util.FireAndForget(FireQueueEmpty, categories);
+                    if (!m_udpServer.OqrEngine.IsRunning)
+                    {
+                        // Asynchronously run the callback
+                        Util.FireAndForget(FireQueueEmpty, categories);
+                    }
+                    else
+                    {
+                        m_udpServer.OqrEngine.QueueRequest(this, categories);
+                    }
                 }
                 else
                 {
@@ -670,7 +677,7 @@ namespace OpenSim.Region.ClientStack.LindenUDP
         /// <param name="o">Throttle categories to fire the callback for,
         /// stored as an object to match the WaitCallback delegate
         /// signature</param>
-        private void FireQueueEmpty(object o)
+        public void FireQueueEmpty(object o)
         {
 //            m_log.DebugFormat("[LLUDPCLIENT]: FireQueueEmpty for {0} in {1}", AgentID, m_udpServer.Scene.Name);
 
diff --git a/OpenSim/Region/ClientStack/Linden/UDP/LLUDPServer.cs b/OpenSim/Region/ClientStack/Linden/UDP/LLUDPServer.cs
index 465c86bef6..3c9bb1bd82 100644
--- a/OpenSim/Region/ClientStack/Linden/UDP/LLUDPServer.cs
+++ b/OpenSim/Region/ClientStack/Linden/UDP/LLUDPServer.cs
@@ -355,6 +355,13 @@ namespace OpenSim.Region.ClientStack.LindenUDP
         /// </summary>
         private IClientAPI m_currentIncomingClient;
 
+        /// <summary>
+        /// Experimental facility to run queue empty processing within a controlled number of threads rather than
+        /// requiring massive numbers of short-lived threads from the threadpool when there are a high number of 
+        /// connections.
+        /// </summary>
+        public OutgoingQueueRefillEngine OqrEngine { get; private set; }
+
         public LLUDPServer(
             IPAddress listenIP, ref uint port, int proxyPortOffsetParm, bool allow_alternate_port,
             IConfigSource configSource, AgentCircuitManager circuitManager)
@@ -432,6 +439,8 @@ namespace OpenSim.Region.ClientStack.LindenUDP
 
             if (usePools)
                 EnablePools();
+
+            OqrEngine = new OutgoingQueueRefillEngine(this);
         }
 
         public void Start()
@@ -469,7 +478,7 @@ namespace OpenSim.Region.ClientStack.LindenUDP
 
             Watchdog.StartThread(
                 OutgoingPacketHandler,
-                string.Format("Outgoing Packets ({0})", Scene.RegionInfo.RegionName),
+                string.Format("Outgoing Packets ({0})", Scene.Name),
                 ThreadPriority.Normal,
                 false,
                 true,
@@ -479,7 +488,7 @@ namespace OpenSim.Region.ClientStack.LindenUDP
 
         public void Stop()
         {
-            m_log.Info("[LLUDPSERVER]: Shutting down the LLUDP server for " + Scene.RegionInfo.RegionName);
+            m_log.Info("[LLUDPSERVER]: Shutting down the LLUDP server for " + Scene.Name);
             base.StopOutbound();
             base.StopInbound();
         }
diff --git a/OpenSim/Region/ClientStack/Linden/UDP/OutgoingQueueRefillEngine.cs b/OpenSim/Region/ClientStack/Linden/UDP/OutgoingQueueRefillEngine.cs
new file mode 100644
index 0000000000..8777402fc4
--- /dev/null
+++ b/OpenSim/Region/ClientStack/Linden/UDP/OutgoingQueueRefillEngine.cs
@@ -0,0 +1,267 @@
+/*
+ * Copyright (c) Contributors, http://opensimulator.org/
+ * See CONTRIBUTORS.TXT for a full list of copyright holders.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in the
+ *       documentation and/or other materials provided with the distribution.
+ *     * Neither the name of the OpenSimulator Project nor the
+ *       names of its contributors may be used to endorse or promote products
+ *       derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+using System;
+using System.Collections.Concurrent;
+using System.Reflection;
+using System.Threading;
+using log4net;
+using OpenSim.Framework;
+using OpenSim.Framework.Monitoring;
+using OpenSim.Region.Framework.Scenes;
+
+namespace OpenSim.Region.ClientStack.LindenUDP
+{
+    public struct RefillRequest
+    {
+        public LLUDPClient Client;
+        public ThrottleOutPacketTypeFlags Categories;
+
+        public RefillRequest(LLUDPClient client, ThrottleOutPacketTypeFlags categories)
+        {
+            Client = client;
+            Categories = categories;
+        }
+    }
+
+    public class OutgoingQueueRefillEngine
+    {
+        private static readonly ILog m_log = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType);
+
+        public bool IsRunning { get; private set; } 
+
+        /// <summary>
+        /// The timeout in milliseconds to wait for at least one event to be written when the recorder is stopping.
+        /// </summary>
+        public int RequestProcessTimeoutOnStop { get; set; }
+
+        /// <summary>
+        /// Controls whether we need to warn in the log about exceeding the max queue size.
+        /// </summary>
+        /// <remarks>
+        /// This is flipped to false once queue max has been exceeded and back to true when it falls below max, in 
+        /// order to avoid spamming the log with lots of warnings.
+        /// </remarks>
+        private bool m_warnOverMaxQueue = true;
+
+        private BlockingCollection<RefillRequest> m_requestQueue;
+
+        private CancellationTokenSource m_cancelSource = new CancellationTokenSource();
+
+        private LLUDPServer m_udpServer;
+
+        /// <summary>
+        /// Used to signal that we are ready to complete stop.
+        /// </summary>
+        private ManualResetEvent m_finishedProcessingAfterStop = new ManualResetEvent(false);
+
+        public OutgoingQueueRefillEngine(LLUDPServer server)
+        {
+            RequestProcessTimeoutOnStop = 5000;
+            m_udpServer = server;
+
+            MainConsole.Instance.Commands.AddCommand(
+                "Debug",
+                false,
+                "debug lludp oqre",
+                "debug lludp oqre <start|stop|status>",
+                "Start, stop or get status of OutgoingQueueRefillEngine.",
+                "Experimental.",
+                HandleOqreCommand);
+        }
+
+        public void Start()
+        {
+            lock (this)
+            {
+                if (IsRunning)
+                    return;
+
+                IsRunning = true;
+
+                m_finishedProcessingAfterStop.Reset();
+
+                m_requestQueue = new BlockingCollection<RefillRequest>(new ConcurrentQueue<RefillRequest>(), 5000);
+
+                Watchdog.StartThread(
+                    ProcessRequests,
+                    String.Format("OutgoingQueueRefillEngineThread ({0})", m_udpServer.Scene.Name),
+                    ThreadPriority.Normal,
+                    false,
+                    true,
+                    null,
+                    int.MaxValue);
+            }
+        }
+
+        public void Stop()
+        {   
+            lock (this)
+            {
+                try
+                {
+                    if (!IsRunning)
+                        return;
+
+                    IsRunning = false;
+
+                    int requestsLeft = m_requestQueue.Count;
+
+                    if (requestsLeft <= 0)
+                    {
+                        m_cancelSource.Cancel();
+                    }
+                    else 
+                    {
+                        m_log.InfoFormat("[OUTGOING QUEUE REFILL ENGINE]: Waiting to write {0} events after stop.", requestsLeft);
+
+                        while (requestsLeft > 0)
+                        {
+                            if (!m_finishedProcessingAfterStop.WaitOne(RequestProcessTimeoutOnStop))
+                            {
+                                // After timeout no events have been written
+                                if (requestsLeft == m_requestQueue.Count)
+                                {
+                                    m_log.WarnFormat(
+                                        "[OUTGOING QUEUE REFILL ENGINE]: No requests processed after {0} ms wait.  Discarding remaining {1} requests", 
+                                        RequestProcessTimeoutOnStop, requestsLeft);
+
+                                    break;
+                                }
+                            }
+
+                            requestsLeft = m_requestQueue.Count;
+                        }
+                    }
+                }
+                finally
+                {
+                    m_cancelSource.Dispose();
+                    m_requestQueue = null;
+                }
+            }
+        }
+
+        public bool QueueRequest(LLUDPClient client, ThrottleOutPacketTypeFlags categories)
+        {
+            if (m_requestQueue.Count < m_requestQueue.BoundedCapacity)
+            {
+//                m_log.DebugFormat(
+//                    "[OUTGOING QUEUE REFILL ENGINE]: Adding request for categories {0} for {1} in {2}", 
+//                    categories, client.AgentID, m_udpServer.Scene.Name);
+
+                m_requestQueue.Add(new RefillRequest(client, categories));
+
+                if (!m_warnOverMaxQueue)
+                    m_warnOverMaxQueue = true;
+
+                return true;
+            }
+            else
+            {
+                if (m_warnOverMaxQueue)
+                {
+                    m_log.WarnFormat(
+                        "[OUTGOING QUEUE REFILL ENGINE]: Request queue at maximum capacity, not recording request from {0} in {1}", 
+                        client.AgentID, m_udpServer.Scene.Name);
+
+                    m_warnOverMaxQueue = false;
+                }
+
+                return false;
+            }
+        }
+
+        private void ProcessRequests()
+        {
+            try
+            {
+                while (IsRunning || m_requestQueue.Count > 0)
+                {
+                    RefillRequest req = m_requestQueue.Take(m_cancelSource.Token);
+
+    //                QueueEmpty callback = req.Client.OnQueueEmpty;                      
+    //
+    //                if (callback != null)
+    //                {               
+    //                    try 
+    //                    { 
+    //                        callback(req.Categories); 
+    //                    }
+    //                    catch (Exception e) 
+    //                    { 
+    //                        m_log.Error("[OUTGOING QUEUE REFILL ENGINE]: ProcessRequests(" + req.Categories + ") threw an exception: " + e.Message, e); 
+    //                    }
+    //                }
+
+                    req.Client.FireQueueEmpty(req.Categories);
+                }
+            }
+            catch (OperationCanceledException)
+            {
+            }
+
+            m_finishedProcessingAfterStop.Set();
+        }
+
+        private void HandleOqreCommand(string module, string[] args)
+        {
+            if (SceneManager.Instance.CurrentScene != null && SceneManager.Instance.CurrentScene != m_udpServer.Scene)
+                return;
+
+            if (args.Length != 4)
+            {
+                MainConsole.Instance.Output("Usage: debug lludp oqre <stop|start|status>");
+                return;
+            }
+
+            string subCommand = args[3];
+
+            if (subCommand == "stop")
+            {
+                Stop();
+                MainConsole.Instance.OutputFormat("Stopped OQRE for {0}", m_udpServer.Scene.Name);
+            }
+            else if (subCommand == "start")
+            {
+                Start();
+                MainConsole.Instance.OutputFormat("Started OQRE for {0}", m_udpServer.Scene.Name);
+            }
+            else if (subCommand == "status")
+            {
+                MainConsole.Instance.OutputFormat("OQRE in {0}", m_udpServer.Scene.Name);
+                MainConsole.Instance.OutputFormat("Running: {0}", IsRunning);
+                MainConsole.Instance.OutputFormat(
+                    "Requests waiting: {0}", IsRunning ? m_requestQueue.Count.ToString() : "n/a");
+            }
+            else 
+            {
+                MainConsole.Instance.OutputFormat("Unrecognized OQRE subcommand {0}", subCommand);
+            }
+        }
+    }
+}
\ No newline at end of file