TN3270E Service Error 503 - Session dropped due to inactivity (166845)

SUMMARY

The SNA Server TN3270 Server configuration includes an Idle Timeout parameter which causes the server to disconnect a TN3270 client session after the session has been inactive for the idle timeout period. The idle timeout period defaults to 120 minutes or 2 hours.

When the Idle Timeout expires for a TN3270 client session, the TN3270 server drops the client's SNA session and sends the following message to the TN3270 client to display to the user:

TN3270E Service Error 503
Session terminated due to inactivity.

When this occurs, the TN3270 Server will also report the following event to the Windows NT Server Event Viewer Application log:

Event ID: 603
Source: TN3270 Server
Description:
TN3270(E) session with client at <client IP address and port> using
LU <luname> terminated abnormally because:

TN3270E Service Error 503
Session terminated due to inactivity

NOTE: Event ID 603 can occur for a variety of reasons. Service Error 503 is a specific cause for an abnormal session termination caused only by the TN3270 Server's idle timeout parameter.

MORE INFORMATION

The TN3270 Server Idle Timeout parameter can be set from 1 minute to 1440 minutes (or 1 day). Here are instructions for setting this parameter:

If you are using SNA Server 2.11 (or 2.11 service pack 1 or 2), run the TN3270 Service Admin program, and then click Options.
If you are using SNA Server 3.0 or later versions, run the SNA Server Manager program, right-click the TN3270 Server, click Properties, and then click the Settings folder.