Microsoft KB Archive/267902

= Applications Fail to Receive Data When Opening LUA LU =

Article ID: 267902

Article Last Modified on 12/29/2003

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APPLIES TO


 * Microsoft SNA Server 4.0 Service Pack 3

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This article was previously published under Q267902



SYMPTOMS
After you upgrade to SNA Server 4.0 to Service Pack 3, an LUA RUI application cannot open a new LUA Pooled session. After running for several days, the application fails to receive any host data after opening a new session from an LUA pool. The SNA Server 3270 and DLC or SNA message traces show that the SNA Server service receives an OPEN SSCP request from the LUA application, but it never sends a new NOTIFY(SLU Enabled) message to the host. Therefore, the LUA application never receives any host data over the session.

This problem may also occur in 3270 sessions with any 3270 emulator.



CAUSE
This problem is inadvertently introduced when the fix described in the following Knowledge Base article is implemented:

235959 SNA Server May Fail to Reestablish a Session Under Certain Conditions

Due to this update, SNA Server incorrectly discards the host TERMSELF response when the SNA sequence number on the session is set to X'7FFF'. Further attempts to open the session succeed, but the SNA Server fails to send any further messages on the SSCP-LU session.



RESOLUTION
To resolve this problem, obtain the latest service pack for SNA Server 4.0. For additional information, click the following article number to view the article in the Microsoft Knowledge Base:

215838 How to Obtain the Latest SNA Server Version 4.0 Service Pack



STATUS
Microsoft has confirmed that this is a problem in Microsoft SNA Server version 4.0 Service Pack 3.

This problem was first corrected in SNA Server 4.0 Service Pack 4.



MORE INFORMATION
This problem causes SNA Server to discard any host response on an SSCP-LU session that has a SNA sequence number of 0x7FFF. This will likely cause the LU to stop responding (hang). The following excerpt from an SNA Server 3270 and DLC message trace exhibits this problem, showing the last messages that flow over LU #02. The node never sends the NOTIFY(SLU Disabled) after it receives the UNBIND +RSP. Note that the SNA sequence number for the TRMSLF (TERMSELF) response received on the SSCP-LU session is 0x7FFF.

NOTE: SNA traces may vary from the following example.

|0000009a.0000009c FMI  --- 09:46:13.0226
 * 0000009a.0000009c FMI  0B1D0001->01020202 CLOSE SSCP REQUEST
 * 0000009a.0000009c FMI
 * 0000009a.0000009c FMI   Header  at address 01194C6C, 0 elements
 * 0000009a.0000009c FMI  01011101 E0000000 00000002 01000C01
 * 0000009a.0000009c FMI  --- 09:46:13.0226
 * 0000009a.0000009c FMI  01020202->0B1D0001 CLOSE SSCP RSP OK
 * 0000009a.0000009c FMI
 * 0000009a.0000009c FMI   Header  at address 01194C6C, 0 elements
 * 0000009a.0000009c FMI  02011101 E0000000 00000002 01000C01
 * 0000009a.0000009c DLC  --- 09:46:13.0236
 * 0000009a.0000009c DLC  01020101->04161000 DLC DATA
 * 0000009a.0000009c DLC                     DAF:00 OAF:02 ODAI:off Normal
 * 0000009a.0000009c DLC                     TRMSLF RQD FMD FI BC EC DR1
 * 0000009a.0000009c DLC
 * 0000009a.0000009c DLC   Header  at address 0119548C, 1 elements
 * 0000009a.0000009c DLC  03B0B006 00002C00 00027FFF 01000C01
 * 0000009a.0000009c DLC
 * 0000009a.0000009c DLC   Element at address 01B89698, start 10, end 18
 * 0000009a.0000009c DLC  0B800001 068300F3 00
 * 0000009a.0000009c DLC  --- 09:46:14.0217
 * 0000009a.0000009c DLC  04161000->01020101 DLC DATA
 * 0000009a.0000009c DLC                     DAF:02 OAF:00 ODAI:off Normal
 * 0000009a.0000009c DLC                     TRMSLF +RSP FMD FI BC EC DR1
 * 0000009a.0000009c DLC
 * 0000009a.0000009c DLC   Header  at address 01194B68, 1 elements
 * 0000009a.0000009c DLC  06050100 00002C00 02007FFF 01000C01
 * 0000009a.0000009c DLC
 * 0000009a.0000009c DLC   Element at address 01B8932C, start 10, end 15
 * 0000009a.0000009c DLC  8B800001 0683
 * 0000009a.0000009c DLC  --- 09:46:15.0169
 * 0000009a.0000009c DLC  04161000->01020101 DLC DATA
 * 0000009a.0000009c DLC                     DAF:02 OAF:01 ODAI:off Exp.
 * 0000009a.0000009c DLC                     UNBIND RQD SC  FI BC EC DR1
 * 0000009a.0000009c DLC
 * 0000009a.0000009c DLC   Header  at address 01194E40, 1 elements
 * 0000009a.0000009c DLC  06060100 00002D00 020145D0 01000C01
 * 0000009a.0000009c DLC
 * 0000009a.0000009c DLC   Element at address 01B860FC, start 10, end 14
 * 0000009a.0000009c DLC  6B800032 01
 * 0000009a.0000009c DLC  --- 09:46:15.0169
 * 0000009a.0000009c DLC  01020101->04161000 DLC DATA
 * 0000009a.0000009c DLC                     DAF:01 OAF:02 ODAI:off Exp.
 * 0000009a.0000009c DLC                     UNBIND +RSP SC  FI BC EC DR1
 * 0000009a.0000009c DLC
 * 0000009a.0000009c DLC   Header  at address 01194E40, 1 elements
 * 0000009a.0000009c DLC  06060100 00002D00 010245D0 01000C01
 * 0000009a.0000009c DLC
 * 0000009a.0000009c DLC   Element at address 01B860FC, start 10, end 13
 * 0000009a.0000009c DLC  EB800032

Keywords: kbbug kbfix kbsna400presp4fix kbqfe kbsna400sp4fix KB267902

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