ACTPU(ERP)/ACTLU(ERP) Requests Not Sent To Downstream Systems (195401)

SYMPTOMS

SNA Server fails to send ACTPU(ERP) and ACTLU(ERP) requests to devices connected to SNA Server as DSPUs (Downstream PUs) even when it receives ACTPU(ERP) and ACTLU(ERP) requests from its upstream connection to a mainframe. In these cases, SNA Server sends ACTPU(COLD) and ACTLU(COLD) requests to the DSPUs.

If the DSPU doesn't support ACTPU(COLD) or ACTLU(COLD) requests, the DSPU may reject the request with an error response with an IBM Sense Code of 0x'0835'. This sense code is defined as Invalid Parameters.

In one reported case, the DSPU was an IBM AIX system running IBM's Communications Server for AIX. In this case, the AIX system rejected the ACTLU(COLD) request from the SNA Server with a IBM Sense Code of 0x'08350001', where 0x'0001' is the offset of the rejected request that caused the problem. Offset 0x'0001' of an ACTLU Request contains the setting for the activation type requested, which is either COLD or ERP.

Please refer to the IBM SNA Formats Guide (GA27-3136) for more details on the ACTPU and ACTLU RUs (Request Units). This manual also includes information on IBM Sense Codes.

In addition, the SNA Server may log an event similar to the following in the Windows NT Application Event Log when this occurs:

   Event ID: 20
   Source: SNA Server
   Description: Negative Response Received on Connection 
                <connection name>
   (SENSE = 0835)

RESOLUTION

SNA Server 3.0

To resolve this problem, obtain the latest service pack for SNA Server version 3.0. For additional information, click the following article number to view the article in the Microsoft Knowledge Base:

184307 How to Obtain the Latest SNA Server Version 3.0 Service Pack

SNA Server 4.0

This problem was corrected in the latest SNA Server version 4.0 U.S. Service Pack. For information on obtaining this Service Pack, query on the following word in the Microsoft Knowledge Base (without the spaces):

   S E R V P A C K

MORE INFORMATION

Please refer to the following Knowledge Base articles for more information on SNA Server's support of ACTPU(ERP) and ACTLU(ERP) requests:

   ARTICLE-ID: Q138469
   TITLE     : SNA Server Support for ACTPU (ERP) and ACTLU (ERP)

   ARTICLE-ID: Q153253
   TITLE     : SNA Server 3270 Sessions Not Recovered with Eicon WAN Server

WARNING: If you use Registry Editor incorrectly, you may cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that you can solve problems that result from using Registry Editor incorrectly. Use Registry Editor at your own risk.

In cases where ACTLU(COLD) requests need to be sent to DSPU systems, the following registry entry needs to be configured:

Start Registry Editor (Regedt32.exe).
Locate the following key in the registry:
HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\SnaServr\Parameters
On the Edit menu, click Add Value, and then add the following registry value:
```
      Value Name: ACTLUCOLD
      Data Type:  REG_SZ
      Value:      YES
						
```
NOTE: Value can be set to anything. As long as the ACTLUCOLD entry is listed with any value, SNA Server will send ACTLU(COLD) requests to DSPUs.
Quit Registry Editor.

After applying the update:

SNA Server always sends ACTPU(ERP) requests to DSPUs unless the ACTPUERP registry entry is set to NO or OFF or 0 as described in the following Knowledge Base Article:
```
   ARTICLE-ID: Q138469
   TITLE     : SNA Server Support for ACTPU (ERP) and ACTLU (ERP)
						
```
SNA Server always sends ACTLU(ERP) requests to DSPUs unless the ACTLUCOLD registry is defined as described previously.