Microsoft KB Archive/140829

= TN3270 Clients Do Not Accept "Do TN3270E" =

Article ID: 140829

Article Last Modified on 10/22/2003

-

APPLIES TO


 * Microsoft SNA Server 3.0, when used with:
 * Microsoft Windows NT 4.0

-



This article was previously published under Q140829





SYMPTOMS
"Do TN3270E" is a command sent from the TN3270E Server Service to the TN3270 emulator during session initialization. It asks the TN3270 emulator whether it can support the TN3270E protocol. Some TN3270 clients do not accept the "Do TN3270E" message from the TN3270E server. This prevents session establishment between the TN3270 client and TN3270E Server Service. Sending the "Do TN3270E" command is a legal command according to RFC 1647."

RFC 1647 states the Following:

"Telnet clients and servers would be free to negotiate support of the TN3270E option or not. If either side does not support TN3270E, traditional TN3270 can be used; otherwise, a sub-negotiation will occur to determine what subset of TN3270E will be used on the session. It is anticipated that a client or server capable of both types of 3270 emulation would attempt to negotiate TN3270E first, and only negotiate traditional tn3270 if the other side refuses TN3270E."

SAMPLE TRACE
>12/08 11:18:16.828 (+ smidgen ) Event=TEV_Started

>12/08 11:18:30.217 (+ 13 secs ) Event=TEV_DataToClient Thread = 0x0000005E Session = 0x0007A718  Socket = 0x000001B4 DO TN3270E Number of bytes = 3

>12/08 11:18:30.217 (+ smidgen ) Event=TEV_TCPSendIssued Thread = 0x0000005E Session = 0x0007A718  Socket = 0x000001B4 Number of bytes = 3 000000 fffd 28                                  !..(             !

>12/08 11:18:30.257 (+ 40 msecs) Event=TEV_TCPRecvIssued Thread = 0x0000005E Session = 0x0007A718  Socket = 0x000001B4

>12/08 11:18:30.277 (+ 20 msecs) Event=TEV_TCPSendCompleted Thread = 0x0000005E Session = 0x0007A718  Socket = 0x000001B4 Bytes transferred = 3

>12/08 11:19:09.403 (+ 39 secs ) Event=TEV_TCPRecvCompleted Thread = 0x0000005E Session = 0x0007A718  Socket = 0x000001B4 Bytes returned = 0

>12/08 11:19:09.423 (+ 20 msecs) Event=TEV_SessionTerminationScheduled Thread = 0x0000005E Session = 0x0007A718  Socket = 0x000001B4 NormalTermination

>12/08 11:19:09.463 (+ 40 msecs) Event=TEV_SessionTermination Thread = 0x0000005E Session = 0x0007A718  Socket = 0x000001B4 Session terminated



RESOLUTION
The TN3270E Server has a new registry entry that can be used to turn off TN3270E support:   Subtree:   HKEY_LOCAL_MACHINE Key:      \currentcontrolset\services\tn3270\parameters\NoTN3270E Type:     REG_EXPAND_SZ Value:    ON When this value is set to ON, the server reverts to being a TN3270 Server. This registry setting effects all sessions; not just ones from TN3270 emulators.



STATUS
This feature is included in the latest U.S. Service Pack for SNA Server for Windows NT, version 2.11. For information on obtaining the Service Pack, query on the following word in the Microsoft Knowledge Base (without the spaces):

S E R V P A C K

Additional query words: prodsna

Keywords: kbbug kbfix kbnetwork KB140829

-

[mailto:TECHNET@MICROSOFT.COM Send feedback to Microsoft]

© Microsoft Corporation. All rights reserved.