Sna Host Logon; Ascii Host Logon - IBM 3708 Description

SNA Host Logon
Up to two SNA hosts can be listed on the 3708's Host Selection (C3) screen. The
desired SNA host may be accessed by entering the number associated with the SNA
host on the Host Selection screen and pressing Enter. If the host is not active (LU
not activated), the 3708 notifies you with a HOST UNAVAILABLE, RETRY LATER
message.
If the LU is active and the host is available, the 3708 transmits a NOTIFY (power
on) command to the host immediately after the host is selected. The NOTIFY
(power on) command informs the host that your terminal is active and ready to
communicate.
If the 3708 logon screens are excluded or the Host Selection screen is suppressed, the
3708 transmits the NOTIFY (power on) command immediately after it has detected
that the downstream device is active.
The 3708 then transmits its Logon Indication Screen (C4), if it is enabled, and you
may enter your application logon. Depending upon the host's configuration, you
may receive an SNA host logon screen (for example, VT AM message 10). This
message follows the 3708's Logon Indication screen. The host may also be
configured to automatically BIND the downstream device. The BIND flows from
the host after the 3708 transmits the NOTIFY (power on).
Communication before the BIND is to the host system's SSCP (system services
control point). Only after the host application transmits a BIND and Start Data
Traffic (SDT) command can communication occur with the host application.
ASCII Host Logon
Up to nine ASCII hosts may be listed on the 3708's Host Selection (C3) screen. The
desired ASCII host may be accessed by entering the number associated with the
ASCII host on the Host Selection screen and pressing Enter. If the host is not
active, the 3708 notifies you with a HOST UNAVAILABLE, RETRY LATER message.
If the host is available, the 3708 displays a ASCI I HOST CONNECTED message and allow
the user to logon to the ASCII host.
If the 3708 logon screens are excluded or the Host Selection (C3) screen is
suppressed, access to ASCII host is not allowed.
The speed of the ASCII host and the ASCII terminal do not need to be the same. If
there is a line speed difference, however, loss of data can occur if the accumulated
backlog of data in the 3708 exceeds 979 bytes (see Chapter 6, "ASCII Pass-Through
Mode" for more information).
Chapter 2. 3708 Operation
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