Article ID: 317651
Article Last Modified on 11/18/2004
APPLIES TO
- Microsoft SNA Server 4.0
- Microsoft SNA Server 4.0 Service Pack 1
- Microsoft SNA Server 4.0 Service Pack 2
This article was previously published under Q317651
SUMMARY
TN3287 print jobs may fail to print when a host application sends multiple print jobs that are delimited by a Begin Bracket (BB) and End Bracket (EB) sequence. The first print job may print successfully, but subsequent print jobs may fail to print.
This problem occurs with some third-party emulators that provide support for TN3287 print sessions.
MORE INFORMATION
TN3287 printing support was added to the TN3270 specification in RFC 1646. The TN3287 specification indicates that a TN3270 server must use an End-Of-Record (EOR) command as a delimiter for TN3287 data streams. TN3287 emulators are required to respond to each EOR command that is received with a Printer Status message.
When the TN3270 server receives from the host system a zero-length Request Unit (RU) with the EB bit set to indicate the end of a print job, the TN3270 server sends an EOR command to the TN3287 emulator.
If the TN3287 emulator does not respond to the EOR command with a Printer Status message, then the TN3270 server cannot send a response to the host system to indicate that the print data has been acknowledged by the printer. Because the host system does not receive a response, the host system queues subsequent print jobs, which fail to print.
The TN3270 service has been changed to enable the TN3270 server to send an acknowledgement (+RSP) to the host system when the TN3270 server receives a zero-length RU with the EB bit set. This change does not require a Printer Status message from the TN3287 emulator.
After the TN3270 server sends the acknowledgement to the host system, the TN3270 server sends the Abort Output (AO) command, which indicates the end of a print job, to the TN3287 emulator. The TN3287 server sends this AO command even if the TN3287 emulator does not send a Printer Status message.
The new behavior resolves the described problem for those TN3287 emulators that are not fully compliant with RFC 1646.
This feature is available in the latest service pack for SNA Server version 4.0. For additional information, refer to the following article in the Microsoft Knowledge Base:
215838 How to Obtain the Latest SNA Server Version 4.0 Service Pack
This feature was first included in SNA Server version 4.0 Service Pack 3. Please refer to the following Internet Enginering Task Force (IETF) document for more details about the TN3287 specifications:
RFC 1646: TN3270 Extensions for LUname and Printer Selection
Keywords: kbinfo kbqfe KB317651
