Brian

> The only key that is not passed through is the ATTN key. This 'breaks' 
transparent mode and reverts to linemode, enabling you to enter telnet 
control commands such as 'quit', for example.

Describing the use of "Attn" as causing the connection to "revert to linemode" 
is misleading. It allows the end user to send commands to the TELNET server, 
as you stated. "Reverting to linemode" implies that, somehow, the SNA session 
with the SNA application changes from one which uses the 3270 data stream 
to one which uses the 3767 data stream, more strictly, the SNA character 
stream (SCS).

Incidentally, in the CS IP User’s Guide and Commands manual I find only PA1 
mentioned as being used to allow entry of commands to the TELNET server. 
With truly SNA, LU type 2, sessions, use of the Attn key causes TSO to 
recognise an "attention" condition, the equivalent of which with non-SNA, LU 
type 0 (using the 3270 data stream), sessions is PA1. Reading the use of the 
BRK function, I see that an Attn can be passed to the primary LU application, 
presumably only where the TN3270 server is supporting a session bound with 
LU type 2.

I expect what you were thinking of was the PA1 key is not passed directly. 
However once in the state where a TELNET command can be entered, you 
can key PA1 in order that the PA1 can be sent to the primary LU application 
over the SNA session.

> If you try to do that to a 3270 telnet server, you will get an error message 
(or should do anyway) informing you that transparent mode is required.

is completely wrong.

Take a look at the "device types" listed under the description of the 
TELNETDEVICE parameter. If LINEMODE is negotiated, by default the mode 
table entry name INTERACT will be selected and the TN3270 - I know I'm not 
responsible for the misleading name! - server will quite happily attempt to 
persuade the primary LU SNA application that, in the role of representing the 
TELNET user, it requests the use of SNA protocols suitable for a 3767 
keyboard-printer device. Naturally traffic on such an SNA-session/TELNET-
connection concatenation is handled in the same way as a native (non-ISPF 
etc.) TSO conversation on a 3270 device.

Chris Mason

On Thu, 26 Jun 2008 13:51:40 +0100, Bri P <[EMAIL PROTECTED]> 
wrote:

See extracts above.

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