diff --git a/common/rfb/VNCSConnectionST.cxx b/common/rfb/VNCSConnectionST.cxx
index cd5d089..43eb825 100644
--- a/common/rfb/VNCSConnectionST.cxx
+++ b/common/rfb/VNCSConnectionST.cxx
@@ -17,17 +17,6 @@
  * USA.
  */
 
-// Debug output on what the congestion control is up to
-#undef CONGESTION_DEBUG
-
-#include <sys/time.h>
-
-#ifdef CONGESTION_DEBUG
-#include <sys/socket.h>
-#include <netinet/in.h>
-#include <netinet/tcp.h>
-#endif
-
 #include <network/TcpSocket.h>
 
 #include <rfb/ComparingUpdateTracker.h>
@@ -49,33 +38,12 @@
 
 static LogWriter vlog("VNCSConnST");
 
-// This window should get us going fairly fast on a decent bandwidth network.
-// If it's too high, it will rapidly be reduced and stay low.
-static const unsigned INITIAL_WINDOW = 16384;
-
-// TCP's minimal window is 3*MSS. But since we don't know the MSS, we
-// make a guess at 4 KiB (it's probably a bit higher).
-static const unsigned MINIMUM_WINDOW = 4096;
-
-// The current default maximum window for Linux (4 MiB). Should be a good
-// limit for now...
-static const unsigned MAXIMUM_WINDOW = 4194304;
-
-struct RTTInfo {
-  struct timeval tv;
-  int offset;
-  unsigned inFlight;
-};
-
 VNCSConnectionST::VNCSConnectionST(VNCServerST* server_, network::Socket *s,
                                    bool reverse)
   : sock(s), reverseConnection(reverse),
     queryConnectTimer(this), inProcessMessages(false),
     pendingSyncFence(false), syncFence(false), fenceFlags(0),
     fenceDataLen(0), fenceData(NULL),
-    baseRTT(-1), congWindow(0), ackedOffset(0), sentOffset(0),
-    minRTT(-1), seenCongestion(false),
-    congestionTimer(this),
     server(server_), updates(false),
     updateRenderedCursor(false), removeRenderedCursor(false),
     continuousUpdates(false), encodeManager(this), pointerEventTime(0),
@@ -428,10 +396,6 @@
   // - Mark the entire display as "dirty"
   updates.add_changed(server->pb->getRect());
   startTime = time(0);
-
-  // - Bootstrap the congestion control
-  ackedOffset = sock->outStream().length();
-  congWindow = INITIAL_WINDOW;
 }
 
 void VNCSConnectionST::queryConnection(const char* userName)
@@ -697,7 +661,7 @@
     // Initial dummy fence;
     break;
   case 1:
-    handleRTTPong();
+    congestion.gotPong();
     break;
   default:
     vlog.error("Fence response of unexpected type received");
@@ -759,9 +723,7 @@
 bool VNCSConnectionST::handleTimeout(Timer* t)
 {
   try {
-    if (t == &congestionTimer)
-      updateCongestion();
-    else if (t == &queryConnectTimer) {
+    if (t == &queryConnectTimer) {
       if (state() == RFBSTATE_QUERYING)
         approveConnection(false, "The attempt to prompt the user to accept the connection failed");
     }
@@ -775,20 +737,11 @@
 
 void VNCSConnectionST::writeRTTPing()
 {
-  struct RTTInfo rttInfo;
   char type;
 
   if (!cp.supportsFence)
     return;
 
-  memset(&rttInfo, 0, sizeof(struct RTTInfo));
-
-  gettimeofday(&rttInfo.tv, NULL);
-  rttInfo.offset = sock->outStream().length();
-  rttInfo.inFlight = rttInfo.offset - ackedOffset;
-
-  pings.push_back(rttInfo);
-
   // We need to make sure any old update are already processed by the
   // time we get the response back. This allows us to reliably throttle
   // back on client overload, as well as network overload.
@@ -796,63 +749,11 @@
   writer()->writeFence(fenceFlagRequest | fenceFlagBlockBefore,
                        sizeof(type), &type);
 
-  sentOffset = rttInfo.offset;
-
-  // Let some data flow before we adjust the settings
-  if (!congestionTimer.isStarted())
-    congestionTimer.start(__rfbmin(baseRTT * 2, 100));
-}
-
-void VNCSConnectionST::handleRTTPong()
-{
-  struct RTTInfo rttInfo;
-  unsigned rtt, delay;
-
-  if (pings.empty())
-    return;
-
-  rttInfo = pings.front();
-  pings.pop_front();
-
-  rtt = msSince(&rttInfo.tv);
-  if (rtt < 1)
-    rtt = 1;
-
-  ackedOffset = rttInfo.offset;
-
-  // Try to estimate wire latency by tracking lowest seen latency
-  if (rtt < baseRTT)
-    baseRTT = rtt;
-
-  if (rttInfo.inFlight > congWindow) {
-    seenCongestion = true;
-
-    // Estimate added delay because of overtaxed buffers
-    delay = (rttInfo.inFlight - congWindow) * baseRTT / congWindow;
-
-    if (delay < rtt)
-      rtt -= delay;
-    else
-      rtt = 1;
-
-    // If we underestimate the congestion window, then we'll get a latency
-    // that's less than the wire latency, which will confuse other portions
-    // of the code.
-    if (rtt < baseRTT)
-      rtt = baseRTT;
-  }
-
-  // We only keep track of the minimum latency seen (for a given interval)
-  // on the basis that we want to avoid continuous buffer issue, but don't
-  // mind (or even approve of) bursts.
-  if (rtt < minRTT)
-    minRTT = rtt;
+  congestion.sentPing(sock->outStream().length());
 }
 
 bool VNCSConnectionST::isCongested()
 {
-  int offset;
-
   // Stuff still waiting in the send buffer?
   sock->outStream().flush();
   if (sock->outStream().bufferUsage() > 0)
@@ -861,98 +762,8 @@
   if (!cp.supportsFence)
     return false;
 
-  // Idle for too long? (and no data on the wire)
-  //
-  // FIXME: This should really just be one baseRTT, but we're getting
-  //        problems with triggering the idle timeout on each update.
-  //        Maybe we need to use a moving average for the wire latency
-  //        instead of baseRTT.
-  if ((sentOffset == ackedOffset) &&
-      (sock->outStream().getIdleTime() > 2 * baseRTT)) {
-
-#ifdef CONGESTION_DEBUG
-    if (congWindow > INITIAL_WINDOW)
-      fprintf(stderr, "Reverting to initial window (%d KiB) after %d ms\n",
-              INITIAL_WINDOW / 1024, sock->outStream().getIdleTime());
-#endif
-
-    // Close congestion window and allow a transfer
-    // FIXME: Reset baseRTT like Linux Vegas?
-    congWindow = __rfbmin(INITIAL_WINDOW, congWindow);
-
-    return false;
-  }
-
-  offset = sock->outStream().length();
-
-  // FIXME: Should we compensate for non-update data?
-  //        (i.e. use sentOffset instead of offset)
-  if ((offset - ackedOffset) < congWindow)
-    return false;
-
-  // If we just have one outstanding "ping", that means the client has
-  // started receiving our update. In order to not regress compared to
-  // before we had congestion avoidance, we allow another update here.
-  // This could further clog up the tubes, but congestion control isn't
-  // really working properly right now anyway as the wire would otherwise
-  // be idle for at least RTT/2.
-  if (pings.size() == 1)
-    return false;
-
-  return true;
-}
-
-
-void VNCSConnectionST::updateCongestion()
-{
-  unsigned diff;
-
-  if (!seenCongestion)
-    return;
-
-  diff = minRTT - baseRTT;
-
-  if (diff > __rfbmin(100, baseRTT)) {
-    // Way too fast
-    congWindow = congWindow * baseRTT / minRTT;
-  } else if (diff > __rfbmin(50, baseRTT/2)) {
-    // Slightly too fast
-    congWindow -= 4096;
-  } else if (diff < 5) {
-    // Way too slow
-    congWindow += 8192;
-  } else if (diff < 25) {
-    // Too slow
-    congWindow += 4096;
-  }
-
-  if (congWindow < MINIMUM_WINDOW)
-    congWindow = MINIMUM_WINDOW;
-  if (congWindow > MAXIMUM_WINDOW)
-    congWindow = MAXIMUM_WINDOW;
-
-#ifdef CONGESTION_DEBUG
-  fprintf(stderr, "RTT: %d ms (%d ms), Window: %d KiB, Bandwidth: %g Mbps\n",
-          minRTT, baseRTT, congWindow / 1024,
-          congWindow * 8.0 / baseRTT / 1000.0);
-
-#ifdef TCP_INFO
-  struct tcp_info tcp_info;
-  socklen_t tcp_info_length;
-
-  tcp_info_length = sizeof(tcp_info);
-  if (getsockopt(sock->getFd(), SOL_TCP, TCP_INFO,
-                 (void *)&tcp_info, &tcp_info_length) == 0) {
-    fprintf(stderr, "Socket: RTT: %d ms (+/- %d ms) Window %d KiB\n",
-            tcp_info.tcpi_rtt / 1000, tcp_info.tcpi_rttvar / 1000,
-            tcp_info.tcpi_snd_mss * tcp_info.tcpi_snd_cwnd / 1024);
-  }
-#endif
-
-#endif
-
-  minRTT = -1;
-  seenCongestion = false;
+  return congestion.isCongested(sock->outStream().length(),
+                                sock->outStream().getIdleTime());
 }