Command Reference Guide

Administration Commands
define_tn3270_defaults
2.56.1 Supplied Parameters
Parameter Type Length Default
[define_tn3270_defaults]
force_responses constant NO
keepalive_method constant NONE
keepalive_interval decimal 600
Supplied parameters are:
force_responses
Controls client responses on printer sessions. Possible values are:
YES
Always request definite responses from the client printer sessions. Some 3270 emulators are unable
to print large jobs if definite responses are not requested. If necessary, set
force_responses to YES to
avoid problems.
NO
Request responses matching SNA traffic.
keepalive_method
Method for sending keep-alive messages. Keep-alive messages are messages sent to TN3270 clients when
there is no other activity on the connection, to keep the TCP/IP connections to the clients active; this ensures
that failed connections and clients can be detected. If there is no traffic at all on a TCP/IP connection, failure
of the connection or of the client may never be detected, which wastes TN server resources and prevents LUs
from being used for other sessions.
Possible values are:
NONE
Do not send keep-alive messages.
NOP
Send Telnet NOP messages.
TM
Send Telnet DO TIMING-MARK messages.
keepalive_interval
Interval (in seconds) between consecutive keep-alive messages. The interval should be long enough to
minimize network traffic, especially if there are typically many idle client connections. The shorter the keep-
alive interval, the quicker failures are detected, but the more network traffic is generated. If the keep-alive
interval is too short and there are many clients, this traffic can be significant.
Typical values are in the range 600–7200 (10 minutes to 2 hours). The value 0 (zero) is not valid if
keepalive_method is set to NOP or TM.
Because of the way TCP/IP operates, the keepalive interval that you configure is not the exact time that it
will take for the server to recognize that a client has disappeared. The exact time depends on various factors,
but will be no more than twice the configured timeout plus a few extra minutes (the exact number depends
on how TCP/IP is configured).
2.56.2 Returned Parameters
No parameters are returned by SNAplus2 when this command executes successfully.
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