diff --git a/src/java/com/threerings/presents/client/Client.java b/src/java/com/threerings/presents/client/Client.java
index 629936c6d..67984916c 100644
--- a/src/java/com/threerings/presents/client/Client.java
+++ b/src/java/com/threerings/presents/client/Client.java
@@ -1,5 +1,5 @@
 //
-// $Id: Client.java,v 1.32 2002/10/21 18:04:56 mdb Exp $
+// $Id: Client.java,v 1.33 2002/10/29 23:51:26 mdb Exp $
 
 package com.threerings.presents.client;
 
@@ -224,8 +224,9 @@ public class Client
     {
         InvocationService isvc = getService(sclass);
         if (isvc == null) {
-            throw new RuntimeException(sclass.getName() + " isn't available. " +
-                                       "I can't bear to go on.");
+            throw new RuntimeException(
+                sclass.getName() + " isn't available. " +
+                "I can't bear to go on.");
         }
         return isvc;
     }
diff --git a/src/java/com/threerings/presents/client/Communicator.java b/src/java/com/threerings/presents/client/Communicator.java
index 4b232022e..cad8b0b2f 100644
--- a/src/java/com/threerings/presents/client/Communicator.java
+++ b/src/java/com/threerings/presents/client/Communicator.java
@@ -1,5 +1,5 @@
 //
-// $Id: Communicator.java,v 1.21 2002/07/23 05:52:48 mdb Exp $
+// $Id: Communicator.java,v 1.22 2002/10/29 23:51:26 mdb Exp $
 
 package com.threerings.presents.client;
 
@@ -13,6 +13,8 @@ import java.net.InetAddress;
 import java.net.Socket;
 
 import com.samskivert.io.NestableIOException;
+import com.samskivert.util.Interval;
+import com.samskivert.util.IntervalManager;
 import com.samskivert.util.LoopingThread;
 import com.samskivert.util.Queue;
 
@@ -84,6 +86,16 @@ public class Communicator
         // start up the writer thread if everything went successfully
         _reader = new Reader();
         _reader.start();
+
+        // register an interval to send pings when appropriate
+        _piid = IntervalManager.register(new Interval() {
+            public void intervalExpired (int id, Object arg) {
+                if (checkNeedsPing()) {
+                    Log.info("Upstream idle, sending ping.");
+                    postMessage(new PingRequest());
+                }
+            }
+        }, 5000L, null, true);
     }
 
     /**
@@ -99,6 +111,11 @@ public class Communicator
             return;
         }
 
+        // stop our ping interval
+        if (_piid != -1) {
+            IntervalManager.remove(_piid);
+        }
+
         // post a logoff message
         postMessage(new LogoffRequest());
 
@@ -263,6 +280,28 @@ public class Communicator
 
         // then write the framed message to actual output stream
         _fout.writeFrameAndReset(_out);
+
+        // make a note of our most recent write time
+        updateWriteStamp();
+    }
+
+    /**
+     * Makes a note of the time at which we last communicated with the
+     * server.
+     */
+    protected synchronized void updateWriteStamp ()
+    {
+        _lastWrite = System.currentTimeMillis();
+    }
+
+    /**
+     * Checks to see if we need to send a ping to the server because we
+     * haven't communicated in sufficiently long.
+     */
+    protected synchronized boolean checkNeedsPing ()
+    {
+        long now = System.currentTimeMillis();
+        return (now - _lastWrite > PingRequest.PING_INTERVAL);
     }
 
     /**
@@ -507,6 +546,9 @@ public class Communicator
     protected OutputStream _out;
     protected Queue _msgq = new Queue();
 
+    protected int _piid;
+    protected long _lastWrite;
+
     /** We use this to frame our upstream messages. */
     protected FramingOutputStream _fout;
     protected ObjectOutputStream _oout;
diff --git a/src/java/com/threerings/presents/net/PingRequest.java b/src/java/com/threerings/presents/net/PingRequest.java
index 23d059fbe..d478daddd 100644
--- a/src/java/com/threerings/presents/net/PingRequest.java
+++ b/src/java/com/threerings/presents/net/PingRequest.java
@@ -1,5 +1,5 @@
 //
-// $Id: PingRequest.java,v 1.7 2002/07/23 05:52:48 mdb Exp $
+// $Id: PingRequest.java,v 1.8 2002/10/29 23:51:26 mdb Exp $
 
 package com.threerings.presents.net;
 
@@ -10,6 +10,11 @@ import com.threerings.io.ObjectOutputStream;
 
 public class PingRequest extends UpstreamMessage
 {
+    /** The number of milliseconds of idle upstream that are allowed to
+     * elapse before the client sends a ping message to the server to let
+     * it know that we're still alive. */
+    public static final long PING_INTERVAL = 60 * 1000L;
+
     /**
      * Zero argument constructor used when unserializing an instance.
      */
diff --git a/src/java/com/threerings/presents/server/net/AuthingConnection.java b/src/java/com/threerings/presents/server/net/AuthingConnection.java
index ba031de41..1ba547dae 100644
--- a/src/java/com/threerings/presents/server/net/AuthingConnection.java
+++ b/src/java/com/threerings/presents/server/net/AuthingConnection.java
@@ -1,5 +1,5 @@
 //
-// $Id: AuthingConnection.java,v 1.7 2002/09/24 00:50:27 mdb Exp $
+// $Id: AuthingConnection.java,v 1.8 2002/10/29 23:51:26 mdb Exp $
 
 package com.threerings.presents.server.net;
 
@@ -16,8 +16,8 @@ import com.threerings.presents.net.UpstreamMessage;
  * The authing connection manages the client connection until
  * authentication has completed (for better or for worse).
  */
-public class AuthingConnection
-    extends Connection implements MessageHandler
+public class AuthingConnection extends Connection
+    implements MessageHandler
 {
     /**
      * Creates a new authing connection object that will manage the
@@ -27,7 +27,8 @@ public class AuthingConnection
                               NonblockingSocket socket)
         throws IOException
     {
-        super(cmgr, socket);
+        super(cmgr, socket, System.currentTimeMillis());
+
         // we are our own message handler
         setMessageHandler(this);
     }
diff --git a/src/java/com/threerings/presents/server/net/Connection.java b/src/java/com/threerings/presents/server/net/Connection.java
index 64a42f4ce..2e8a37bdd 100644
--- a/src/java/com/threerings/presents/server/net/Connection.java
+++ b/src/java/com/threerings/presents/server/net/Connection.java
@@ -1,5 +1,5 @@
 //
-// $Id: Connection.java,v 1.9 2002/10/26 02:37:59 shaper Exp $
+// $Id: Connection.java,v 1.10 2002/10/29 23:51:26 mdb Exp $
 
 package com.threerings.presents.server.net;
 
@@ -7,6 +7,7 @@ import java.io.EOFException;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
+import java.net.SocketTimeoutException;
 
 import ninja2.core.io_core.nbio.*;
 
@@ -19,6 +20,7 @@ import com.threerings.io.ObjectOutputStream;
 
 import com.threerings.presents.Log;
 import com.threerings.presents.net.DownstreamMessage;
+import com.threerings.presents.net.PingRequest;
 import com.threerings.presents.net.UpstreamMessage;
 
 /**
@@ -36,14 +38,15 @@ public abstract class Connection implements NetEventHandler
      * @param cmgr The connection manager with which this connection is
      * associated.
      * @param socket The socket from which we'll be reading messages.
-     * @param fout The framing output stream via which we'll write
-     * serialized messages to the client.
+     * @param createStamp The time at which this connection was created.
      */
-    public Connection (ConnectionManager cmgr, NonblockingSocket socket)
+    public Connection (ConnectionManager cmgr, NonblockingSocket socket,
+                       long createStamp)
         throws IOException
     {
         _cmgr = cmgr;
         _socket = socket;
+        _lastEvent = createStamp;
 
         // create a select item that will allow us to be incorporated into
         // the main event polling loop
@@ -210,8 +213,11 @@ public abstract class Connection implements NetEventHandler
     /**
      * Called when our client socket has data available for reading.
      */
-    public void handleEvent (Selectable source, short events)
+    public void handleEvent (long when, Selectable source, short events)
     {
+        // make a note that we received an event as of this time
+        _lastEvent = when;
+
         try {
             // we're lazy about creating our input streams because we may
             // be inheriting them from our authing connection and we don't
@@ -248,6 +254,21 @@ public abstract class Connection implements NetEventHandler
         }
     }
 
+    // documentation inherited from interface
+    public void checkIdle (long now)
+    {
+        long idleMillis = now - _lastEvent;
+        if (idleMillis < PingRequest.PING_INTERVAL + LATENCY_GRACE) {
+            return;
+        }
+        if (isClosed()) {
+            return;
+        }
+        Log.info("Disconncecting idle client [conn=" + this +
+                 ", idle=" + idleMillis + "ms].");
+        handleFailure(new SocketTimeoutException("Idle too long"));
+    }
+
     /**
      * Posts a downstream message for delivery to this connection. The
      * message will be delivered by the conmgr thread as soon as it gets
@@ -263,6 +284,8 @@ public abstract class Connection implements NetEventHandler
     protected NonblockingSocket _socket;
     protected SelectItem _selitem;
 
+    protected long _lastEvent;
+
     protected InputStream _in;
     protected FramedInputStream _fin;
     protected ObjectInputStream _oin;
@@ -271,4 +294,9 @@ public abstract class Connection implements NetEventHandler
     protected ObjectOutputStream _oout;
 
     protected MessageHandler _handler;
+
+    /** The number of milliseconds beyond the ping interval that we allow
+     * a client's network connection to be idle before we forcibly
+     * disconnect them. */
+    protected static final long LATENCY_GRACE = 30 * 1000L;
 }
diff --git a/src/java/com/threerings/presents/server/net/ConnectionManager.java b/src/java/com/threerings/presents/server/net/ConnectionManager.java
index 73c8e6442..86dd9d35c 100644
--- a/src/java/com/threerings/presents/server/net/ConnectionManager.java
+++ b/src/java/com/threerings/presents/server/net/ConnectionManager.java
@@ -1,5 +1,5 @@
 //
-// $Id: ConnectionManager.java,v 1.22 2002/10/21 20:56:21 mdb Exp $
+// $Id: ConnectionManager.java,v 1.23 2002/10/29 23:51:26 mdb Exp $
 
 package com.threerings.presents.server.net;
 
@@ -54,9 +54,13 @@ public class ConnectionManager extends LoopingThread
         _litem = new SelectItem(_listener, Selectable.ACCEPT_READY);
         // when an ACCEPT_READY event happens, we do this:
         _litem.obj = new NetEventHandler() {
-            public void handleEvent (Selectable item, short events) {
+            public void handleEvent (
+                long when, Selectable item, short events) {
                 acceptConnection();
             }
+            public void checkIdle (long now) {
+                // we're never idle
+            }
         };
         _selset.add(_litem);
 
@@ -168,6 +172,8 @@ public class ConnectionManager extends LoopingThread
      */
     protected void iterate ()
     {
+        long iterStamp = System.currentTimeMillis();
+
         // close any connections that have been queued up to die
         Connection dconn;
         while ((dconn = (Connection)_deathq.getNonBlocking()) != null) {
@@ -179,6 +185,14 @@ public class ConnectionManager extends LoopingThread
             }
         }
 
+        // close any connections that have seen no network traffic for too
+        // long
+        int ccount = _selset.size();
+        for (int ii = 0; ii < ccount; ii++) {
+            ((NetEventHandler)_selset.elementAt(ii).getObj()).
+                checkIdle(iterStamp);
+        }
+
         // send any messages that are waiting on the outgoing queue
         Tuple tup;
         while ((tup = (Tuple)_outq.getNonBlocking()) != null) {
@@ -221,7 +235,7 @@ public class ConnectionManager extends LoopingThread
             // connections network traffic from here on out
             try {
                 RunningConnection rconn =
-                    new RunningConnection(this, conn.getSocket());
+                    new RunningConnection(this, conn.getSocket(), iterStamp);
                 // we need to keep using the same object input and output
                 // streams from the beginning of the session because they
                 // have contextual state that needs to be preserved
@@ -252,7 +266,8 @@ public class ConnectionManager extends LoopingThread
             try {
                 SelectItem item = active[i];
                 NetEventHandler handler = (NetEventHandler)item.obj;
-                handler.handleEvent(item.getSelectable(), item.revents);
+                handler.handleEvent(
+                    iterStamp, item.getSelectable(), item.revents);
 
             } catch (Exception e) {
                 Log.warning("Error processing network data.");
diff --git a/src/java/com/threerings/presents/server/net/NetEventHandler.java b/src/java/com/threerings/presents/server/net/NetEventHandler.java
index 1365661c3..0929f6342 100644
--- a/src/java/com/threerings/presents/server/net/NetEventHandler.java
+++ b/src/java/com/threerings/presents/server/net/NetEventHandler.java
@@ -1,5 +1,5 @@
 //
-// $Id: NetEventHandler.java,v 1.3 2001/10/11 04:07:53 mdb Exp $
+// $Id: NetEventHandler.java,v 1.4 2002/10/29 23:51:26 mdb Exp $
 
 package com.threerings.presents.server.net;
 
@@ -23,5 +23,11 @@ public interface NetEventHandler
      * The <code>events</code> parameter indicates which event or events
      * have occurred.
      */
-    public void handleEvent (Selectable source, short events);
+    public void handleEvent (long when, Selectable source, short events);
+
+    /**
+     * Called to ensure that this selectable has not been idle for longer
+     * than is possible in happily operating circumstances.
+     */
+    public void checkIdle (long now);
 }
diff --git a/src/java/com/threerings/presents/server/net/RunningConnection.java b/src/java/com/threerings/presents/server/net/RunningConnection.java
index 121821071..b5d13533f 100644
--- a/src/java/com/threerings/presents/server/net/RunningConnection.java
+++ b/src/java/com/threerings/presents/server/net/RunningConnection.java
@@ -1,5 +1,5 @@
 //
-// $Id: RunningConnection.java,v 1.7 2002/09/24 00:50:27 mdb Exp $
+// $Id: RunningConnection.java,v 1.8 2002/10/29 23:51:26 mdb Exp $
 
 package com.threerings.presents.server.net;
 
@@ -20,10 +20,11 @@ public class RunningConnection extends Connection
      * client socket.
      */
     public RunningConnection (ConnectionManager cmgr,
-                              NonblockingSocket socket)
+                              NonblockingSocket socket,
+                              long createStamp)
         throws IOException
     {
-        super(cmgr, socket);
+        super(cmgr, socket, createStamp);
     }
 
     /**