SDLC Connection Fails with Event 23, Qualifier X'002E'

• Microsoft SNA Server, versions 2.11, 2.11SP1, 2.11SP2, 3.0, 3.0SP1, 3.0SP2, 3.0SP3, 4.0, 4.0SP1

SYMPTOMS

When SNA Server and its synchronous data link control (SDLC) link service do not receive an acknowledgement for a transmitted Information Frame (I- Frame) from the underlying SDLC hardware (that is, SDLC Adapter), the following error will be logged in the Windows NT Application Event Log:

   Event ID: 23
   Source: SDLC Link Service
   Description: Connection <connection name> using Link Service <link service 
    name> failed  Qualifier = X'002E' 

CAUSE

I-Frames should generally be acknowledged before the Write Timeout/Retry value of 15 seconds expires. However, it is not possible to change the Write Timeout and Write Retry Limit parameters in the event that a longer timeout is needed because these values are hardcoded.

These parameters were not originally designed to be configurable.

RESOLUTION

SNA Server 3.0

Q184307 How to Obtain the Latest SNA Server Version 3.0 Service Pack

SNA Server 4.0

   S E R V P A C K 

STATUS

Microsoft has confirmed this to be a problem in SNA Server 2.11, 2.11 Service Pack 1, 2.11 Service Pack 2, 3.0, 3.0 Service Pack 1, 3.0 Service Pack 2, 3.0 Service Pack 3, 4.0, and 4.0 Service Pack 1. This problem was first corrected in SNA Server 3.0 Service Pack 4.

MORE INFORMATION

The Write Timeout value is set to 1,000 milliseconds and the Write Retry Limit is set to 15. These values cannot be changed. So, if an I-Frame is not acknowledged within 15 seconds from the time it was sent to the SDLC hardware, the error described above will be logged and the SDLC connection will drop to a Pending state while it attempts to re-establish the SDLC connection to the remote device.

After applying the hotfix above, the Write Timeout and Write Retry Limit parameters can be configured by setting the following registry parameters:

WARNING: Using Registry Editor incorrectly can cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that problems resulting from the incorrect use of Registry Editor can be solved. Use Registry Editor at your own risk.

For information about how to edit the registry, view the "Changing Keys And Values" Help topic in Registry Editor (Regedit.exe) or the "Add and Delete Information in the Registry" and "Edit Registry Data" Help topics in Regedt32.exe. Note that you should back up the registry before you edit it.

1. Start Registry Editor (Regedt32.exe).



2. Locate the following key in the registry: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Snaservr \Parameters NOTE: The above registry key is one path; it has been wrapped for readability.



3. On the Edit menu, click Add Value, and then add the following registry value:

   
         Value Name: SDLCWriteTimeout
         Data Type:  REG_SZ
         Value:      <writetimeout>
   
         where: writetimeout can be from 1 to 65,535 milliseconds.
   
      The default value for this entry is 1,000 milliseconds. If the entry
      does not exist, the default value will be used. 




4. On the Edit menu, click Add Value, and then add the following registry value:

   
         Value Name: SDLCWriteRetries
         Data Type:  REG_SZ
         Value:      <writeretries>
   
         where: writeretries can be from 1 to 65535.
   
      The default value for this entry is 15. If the entry does not exist, the
      default value will be used. 




5. Quit Registry Editor.

Additional query words:

Keywords :
Version : WINDOWS:2.11,2.11SP1,2.11SP2,3.0,3.0SP1,3.0SP2,3.0SP3,4.0,4.0SP1
Platform : WINDOWS
Issue type : kbbug