Unconditional Session Termination - IBM 3708 Description

Unconditional Session Termination
ASCII Hosts
If the 3708 detects the loss of a connection or the power off to a device that is in
session with an SNA host, it ends the SNA session. The action taken depends upon
the state of the SNA session and the host configuration.
State of the Session
BIND has been received, and the 3708
has responded positively to BIND.
This indicates that an
LU - LU session exists.
UNBIND has been received and
BIND is forthcoming.
BIND has not been received. This
indicates that an SSCP - LU session
exists, but not an LU - LU session.
Command Sent to the Host
UNBIND(OF) or TERMSELF( 40) or
TERMSELF(4C)!
NOTIFY, power off.
TERMSELF( 4C)
NOTIFY, power off.
NOTIFY, power off.
This section describes the reasons that the 3708 disconnects a device from an ASCII
host.
Session Termination
The 3708 allows the terminal user to terminate the ASCII host session by using the
disconnect sequence defined for the ASCII host.
It
consists of the BREAK line
condition followed by the 3-character ASCII host disconnect sequence.
When this sequence is used, the 3708 does not disconnect from either the ASCII host
or the terminal. The terminal user is presented with the 3708 host selection screen
(C3), and the ASCII host is immediately available for other terminal connections.
For this reason, it is recommended that the terminal user issue any session ending
sequences defined in the host protocol before entering the BREAK sequence. This
precaution should prevent the next user of the ASCII host from accessing the
previous user's session.
Unconditional Disconnection
When the 3708 recognizes the loss of connection or the power off of either the
ASCII host or the terminal while they are involved in an ASCII pass-through
session, the 3708 disconnects the interface to the partner as well. Each side is then
reconnected. The ASCII host is available for selection by any user and a new 3708
port logon sequence is required at the terminal.
!
Depending on a host port configuration option, the 3708 may transmit an UNBIND (OF) or a TERMSELF. If
TERMSELF is specified, the 3708 transmits either a TERMSELF 40 (the default) or (if nonstandard operating bit
14 is set to 1) a TERMSELF 4C.
Chapter 2. 3708 Operation
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