SNA Server DFT Link Service Outage 0x11 (DSR Failure)

• Microsoft SNA Server, versions 2.0, 2.1, 2.11

SYMPTOMS

When you use the IBMDFT.DLL driver with the Microsoft SNA Server, the receipt of a large amount of data (such as a screen dump) causes the DFT connection to disconnect with an Outage 0x11 message (that is a DSR failure).

CAUSE

The DFT link service is erroneously informing the node that it supports a maximum frame size of 256 bytes. As a result, the node uses a maximum frame size of 256 bytes. When the node has an RU larger than 256 bytes to send to the link service, it segments the RU to stay at or below 256 bytes and sends it in multiple parts. The link service cannot cope with this (expecting to receive only whole RUs), and disconnects the connection.

RESOLUTION

Microsoft has updated the file IBMDFT.DLL to correct this problem.

STATUS

Microsoft has confirmed this to be a problem in SNA Server for Windows NT. This problem was corrected in the latest SNA Server for Windows NT, 2.11 U.S. Service Pack. For information on obtaining the Service Pack, query on the following word in the Microsoft Knowledge Base (without the spaces):

S E R V P A C K

Additional query words: prodsna 2.00 2.10

Keywords : ntnetserv sna211 sna2 sna21
Version : WINDOWS:2.0,2.1,2.11
Platform : WINDOWS
Issue type :