Symptoms
A MetaFrame Presentation Server Client, configured to use “Session Reliability,” establishes an ICA session on TCP port 2598 (instead of port 1494) when connecting to Presentation Server.
Note: When a previous version of the client (Version 7.x) connects to a MetaFrame Presentation Server enabled with Session Reliability, port 1494 is used for ICA sessions.
For more information about session reliability, see:
• CTX103723 – MetaFrame Presentation Server 3.0 for Windows Administrator's Guide
• CTX106319 – MetaFrame Presentation Server 4.0 Administrator's Guide
From the Management Console Help:
Port number (default 2598): Assign the port on which you want the servers in the farm to listen for attempts to reestablish dropped connections.
When session reliability is enabled, the ICA Client tunnels its ICA traffic inside the Common Gateway Protocol and sends the traffic to port 2598. The XTE service acts as a relay, unwrapping the Common Gateway Protocol layer and then forwarding traffic to the ICA listener on port 1494:
Likewise, the Presentation Server sends ICA data to the client by way of the XTE service. If the Common Gateway Protocol connection between the client and the XTE service is broken, the ICA listener can continue to send ICA traffic to the XTE service, where it will be buffered until the client reconnects. The user’s session does not go into a disconnected state as long as the XTE service is buffering data for the user.
On the client, the user’s application will appear frozen while the client attempts to rebuild the Common Gateway Protocol connection. Once the connection is restored, the XTE service flushes the buffered ICA data to the client and the session continues.
Cause
Session reliability is enabled by default on the installation of MetaFrame Presentation Server 3.0.
Resolution
Session reliability may be disabled.
From the Server
Click the server farm node and in the right panel, under Session Reliability, select disable.
From the Program Neighborhood Client
In an Application Set:
For a Custom ICA Connection:
More Information
See Internet Assigned Numbered Authority (IANA) for the ports registered by Citrix.
CTX107902 – Session Reliability and Maximum Number of Connections
CTX109913 – Enabling Session Reliability Switches ICA Traffic from Port 1494 to 2598
CTX104907 – Restarting the IMA Service Disconnects Session Reliability Users
CTX108439 – How to Disable Session Reliability through Web Interface
CTX107659 – Session Reliability Overrides ICA KeepAlive Feature
CTX111591 – Session Reliability May Not Function After Applying SGE300W004
CTX107661 – With Session Reliability, the Actual Time that Sessions Stay Active is Longer Than the Setting
From the Management Console Help:
A session is disconnected after the time that you specify in Seconds to keep sessions active elapses. If you extend the amount of time a session is kept open but remains unresponsive, users may leave the client device, potentially leaving the session accessible to unauthorized users.
After the session is disconnected, the Auto Client Reconnect feature can attempt to reconnect the user to the disconnected session. You can configure Auto Client Reconnect to require authentication.
Per CTX107102 – Presentation Server Program Neighborhood Client for 32-Bit Windows Configuration Guide (INI File Reference), Version 9 there is a parameter SessionReliabilityTTL=X (amount of seconds). It may be necessary to modify both the client and the server values. See also: CTX114117 – Despite Setting the Session Reliability Timeout to Five Minutes in the Management Console, Sessions Timeout After Three Minutes
