diff --git a/src/net/java/sip/communicator/impl/protocol/sip/ProtocolProviderServiceSipImpl.java b/src/net/java/sip/communicator/impl/protocol/sip/ProtocolProviderServiceSipImpl.java
index f730fe4ad..d048c8154 100644
--- a/src/net/java/sip/communicator/impl/protocol/sip/ProtocolProviderServiceSipImpl.java
+++ b/src/net/java/sip/communicator/impl/protocol/sip/ProtocolProviderServiceSipImpl.java
@@ -231,6 +231,13 @@ public class ProtocolProviderServiceSipImpl
      */
     private final XCapClient xCapClient = new XCapClientImpl();
 
+    /**
+     * A list of early processors that can do early processing of received
+     * messages (requests or responses).
+     */
+    private final List<SipMessageProcessor> earlyProcessors =
+        new ArrayList<SipMessageProcessor>();
+
     /**
      * Gets the XCAP client.
      *
@@ -749,6 +756,23 @@ public void processResponse(ResponseEvent responseEvent)
         }
 
         Response response = responseEvent.getResponse();
+
+        synchronized(earlyProcessors)
+        {
+            for (SipMessageProcessor listener : earlyProcessors)
+            {
+                try
+                {
+                    if(!listener.processResponse(responseEvent, null))
+                        return;
+                }
+                catch(Throwable t)
+                {
+                    logger.error("Error pre-processing message", t);
+                }
+            }
+        }
+
         String method = ( (CSeqHeader) response.getHeader(CSeqHeader.NAME))
             .getMethod();
 
@@ -797,6 +821,22 @@ public void processTimeout(TimeoutEvent timeoutEvent)
             return;
         }
 
+        synchronized(earlyProcessors)
+        {
+            for (SipMessageProcessor listener : earlyProcessors)
+            {
+                try
+                {
+                    if(!listener.processTimeout(timeoutEvent, null))
+                        return;
+                }
+                catch(Throwable t)
+                {
+                    logger.error("Error pre-processing message", t);
+                }
+            }
+        }
+
         Request request = transaction.getRequest();
         if (logger.isDebugEnabled())
             logger.debug("received timeout for req=" + request);
@@ -926,6 +966,22 @@ public void processRequest(RequestEvent requestEvent)
             return;
         }
 
+        synchronized(earlyProcessors)
+        {
+            for (SipMessageProcessor listener : earlyProcessors)
+            {
+                try
+                {
+                    if(!listener.processMessage(requestEvent))
+                        return;
+                }
+                catch(Throwable t)
+                {
+                    logger.error("Error pre-processing message", t);
+                }
+            }
+        }
+
         // test if an Event header is present and known
         EventHeader eventHeader = (EventHeader)
             request.getHeader(EventHeader.NAME);
@@ -3167,5 +3223,31 @@ private boolean checkPreferIPv6Addresses()
         // if there is no default setting return the system wide value.
         return Boolean.getBoolean("java.net.preferIPv6Addresses");
     }
-}
 
+    /**
+     * Registers early message processor.
+     * @param processor early message processor.
+     */
+    void addEarlyMessageProcessor(SipMessageProcessor processor)
+    {
+        synchronized (earlyProcessors)
+        {
+            if (!earlyProcessors.contains(processor))
+            {
+                this.earlyProcessors.add(processor);
+            }
+        }
+    }
+
+    /**
+     * Removes the early message processor.
+     * @param processor early message processor.
+     */
+    void removeEarlyMessageProcessor(SipMessageProcessor processor)
+    {
+        synchronized (earlyProcessors)
+        {
+            this.earlyProcessors.remove(processor);
+        }
+    }
+}