Westermo MR Series - Manual (Page 274)

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Web Interface and Command Line Reference Guide www.westermo.com
LCN:
The unit supports up to eight logical X.25/TPAD channels. In practice, the operational limit is
deter mined by the particular service to which you subscribe (usually 4).
Each logical channel must be assigned a valid Logical Channel Number (LCN). The LCN parame-
ter is the value of the first LCN that will be assigned for outgoing X.25 CALLs. The default is
1027.
For incoming calls, the unit accepts the LCN specified by the caller.
LCN direction:
This parameter determines whether the X.25 LCN used for outgoing TPAD calls is incremented
or decremented from the starting value when multiple TPAD instances share one layer 2 (LAPB
or LAPD), connection. The default is “DOWN” and LCNs are decremented, i.e. if the first CALL
uses 1024, the next will use 1023, etc. Setting the parameter to “UP” will cause the LCN to be
incre mented from the start value.
Direct Sync:
This parameter is used to turn direct synchronous mode on or off. When set to On, TPAD
transac tions are transmitted without any “outer” protocol such as X.25, i.e. they are placed
directly in a synchronous frame.
Response timeout (s):
This is the length of time in seconds that the unit will wait for a response to a TPAD transac-
tion request before clearing the TPAD call.
Excessive transaction time (s):
Setting this parameter to a non-zero value causes the unit to generate an “Excessive Transaction
Time” event (code 56) each time a TPAD transaction takes longer that the specified number of
seconds. This could be used in conjunction with an appropriate Event Handler configuration to
generate email alert messages or SNMP traps when TPAD transactions take longer than expect-
ed. See “LOGCODES.TXT” for a complete list of events.
SLA Tran Time (ms):
When the total transaction time exceeds the value (in ms) set in this parameter, the NB SLA
exceptions statistic on the Statistics > TPAD page is incremented. This statistic can be viewed on
the CLI interface by entering the at\mibs=tpad.n.stats command, where n is the TPAD instance.
TID timeout (s):
This specifies the time in seconds before the Terminal ID is considered inactive.
Restart delay (ms):
When the Restarts parameter is set to “On”, the Restart delay value determines how long (in
milli seconds) that the unit will wait before issuing a Restart packet. The default value is 2000 giv-
ing a delay of 2 seconds.
Restarts:
The Restarts parameter is only used in D-channel X.25 mode, i.e. when the specified TPAD
instance has been bound to a LAPD instance.
It is normally possible to make X.28 CALLs immediately following the initial SABM-UA
exchange.
In some cases however, the X.25 network may require an X.25 RESTART before it will accept
X.25 CALLs. The correct mode to select depends upon the particular X.25 service to which
you subscribe.
The default value is “On”. This means that the unit will issue X.25 RESTART packets. To prevent
the unit from issuing RESTART packets set this parameter to “Off”.