DOCUMENT:Q220942 08-MAY-2002 [sna] TITLE :TN5250 Clients May Fail with a STATE_CHECK Error PRODUCT :Microsoft SNA Server PROD/VER:WINDOWS:3.0,3.0SP1,3.0SP2,3.0SP3,4.0,4.0SP1,4.0SP2 OPER/SYS: KEYWORDS:kbsna400sp3fix ====================================================================== ------------------------------------------------------------------------------- The information in this article applies to: - Microsoft SNA Server, versions 3.0, 3.0SP1, 3.0SP2, 3.0SP3, 4.0, 4.0SP1, 4.0SP2 ------------------------------------------------------------------------------- SYMPTOMS ======== TN5250 clients of the the SNA Server TN5250 service may fail with a STATE_CHECK AP_SEND_DATA_NO_LL_BDY, because of the way the datastream is interpreted. CAUSE ===== The TN5250 data stream that is exchanged is composed of a header followed by the 5250 client data stream. The header is variable in length and composed of two parts: - A fixed part This is six octets long and contains the logical record length, record type, and a reserved field. - A variable part This includes a one-octet length field, flags, and an opcode field. The opcode field indicates the operation requested (for example, get/put/read immediate). The 5250 client data stream follows, and is terminated by two octets, (IAC) with value 0xFF, and (EOR) with value 0xFF. The (IAC) (EOR) combination marks the end of the record. To uniquely identify these two octets as the termination, each 0xFF in the data stream is doubled. The problem occurs when the doubled IAC character 0xFF sent by the emulator is exactly between the two SEND buffers (first one ends with FF and second one begins with the remaining FF). The TN5250 translator fails to undouble it (0xFFFF should become 0xFF), so an extra character is sent to APPC. APPC is waiting for a SEND buffer with n characters, and receives a send buffer with n+1 characters. This behavior generates a STATE_CHECK AP_SEND_DATA_NOT_LL_BDY. RESOLUTION ========== To resolve this problem, obtain the latest service pack for SNA Server version 4.0. For additional information, please see the following article in the Microsoft Knowledge Base: Q215838 How to Obtain the Latest SNA Server Version 4.0 Service Pack STATUS ====== Microsoft has confirmed this to be a problem in SNA Server 3.0, 3.0 SP1, 3.0 SP2, 3.0 SP3, SNA Server 4.0, 4.0 SP1, 4.0 SP2. This problem was first corrected in SNA Server version 4.0 Service Pack 3. Additional query words: ====================================================================== Keywords : kbsna400sp3fix Technology : kbAudDeveloper kbSNAServSearch kbSNAServ300 kbSNAServ400 Version : WINDOWS:3.0,3.0SP1,3.0SP2,3.0SP3,4.0,4.0SP1,4.0SP2 Issue type : kbbug Solution Type : kbfix ============================================================================= THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY. Copyright Microsoft Corporation 2002.