XCON: Slow Mail Flow Across X.400 Connector with 289 and 1294 Warnings (257727)


The information in this article applies to:

  • Microsoft Exchange Server 4.0
  • Microsoft Exchange Server 5.0
  • Microsoft Exchange Server 5.5
This article was previously published under Q257727

SYMPTOMS

The two following error messages may be displayed:
Event ID - 289
Source - MSExchangeMTA
Description - A connection to 1% could not be opened.

Event ID -1294
Source - MSExchangeMTA
Description - An association with entity 1% ended abnormally.
Messages also intermittently back up on a message transfer agent (MTA) queue for an X.400 Connector to a remote site. When you stop and restart the MTA, mail flow resumes.

CAUSE

This issue can occur as a result of poor network quality.

WORKAROUND

To work around this issue:
  1. Open the X.400 Connector properties, and click the Override tab.
  2. Under the Request to Send (RTS) values, set Checkpoint Size to 10 (30 is the default), and Window Size to 3 (default value is 5). In the Association Parameters box, set Disconnect to 360 (default value is 120).
  3. Stop and restart the MTA service.
Mail flow should resume and continue.

MORE INFORMATION

Checkpoint size. Sets the amount of data to be transferred before a checkpoint is inserted. If an error occurs and the message must be retransferred, the process restarts from the most recent checkpoint. If you specify zero, no checkpoint is set. If you use a checkpoint, you slightly reduce the transmission speed. Decrease the checkpoint size when the connection is less reliable.

Window size. The number of checkpoints that can go unacknowledged before data transfer is suspended. The greater the window size, the greater the transfer rate. The window size determines the amount of resources set aside for the receiving station. Specify window size only if the checkpoint size is greater than zero.

Disconnect. The amount of time to wait before a connection is terminated because of a previously terminated association.
Modification Type:MinorLast Reviewed:4/28/2005
Keywords:kbprb KB257727
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