Westermo MR Series - Manual (Page 166)

166 6622-3201
Web Interface and Command Line Reference Guide www.westermo.com
RR timer (ms):
This is a standard LAPB/LAPD “Receiver Ready” timer. The default value is 10,000ms (10 sec-
onds) and it should not normally be necessary to change this.
Inactivity timer (s):
This parameter may be used to specify the length of time (in seconds) before the link is discon-
nected if there has been no activity. If this parameter is zero or not specified, then the inactiv-
ity timer is disabled. It is useful to set this to a short period of time (say 120 seconds) when a
LAPB instance is being used over ISDN for example with TPAD. Should the POS device fail to
instruct TPAD to hang up then this timer can be used as a backup hang-up timer thus saving
ISDN call charges.
When LAPB is being used on a synchronous port, this parameter should normally be set to 0.
Inactivity timer when X25 (s):
This parameter may be used to specify the length of time (in seconds) before the link is discon-
nected if there has been no X.25 activity. If this parameter is zero or not specified, then the
inactiv ity timer is disabled.
T1 timer:
This is a standard LAPB/LAPD timer. The default value is 1000 milliseconds (1 second) and
under normal circumstances, it should not be necessary to change it.
T200 timer:
This is the standard LAPB/LAPD re-transmit timer. The default value is 1000 milliseconds (1 sec-
ond) and under normal circumstances, it should not be necessary to change it.
N400 counter:
This is the standard LAPB/LAPD retry counter. The default value is 3 and it should not normally
be necessary to change this.
Window size:
This parameter is used to set the X.25 window size. The value range is from 1 to 7 with the
default being 7.
Restart when activate:
This parameter can be set to “No” or “Immediate”. When set to “Immediate”, the LAPB
instance will send an X.25 restart packet immediately on receipt of an SABM (Set Asynchronous
Balanced Mode) frame. If the parameter is set to “No”, then no X.25 restart is sent.
Keep Activated:
When this parameter is set to “Off”, the ISDN LAPB link will be disconnected if the user sends
a DISC or when a PAD session is terminated (e.g. by the “log” command or because DTR goes
off). By setting Keep activated to “On”, the link will not be disconnected under these circum-
stances. Instead, when a DISC is received, the unit will response with a UA frame as usual but
will immedi ately follow this with a SABM to re-establish the link. Similarly, the unit will not dis-
connect the link after a log command or when DTR goes off.
Passive timer (ms):
This parameter sets the length of time (in milliseconds), that the LAPB instance will wait from
an ISDN B-channel becoming active before attempting to establish a LAPB connection, i.e. the
length of time for which the LAPB instance stays passive. The default is 0 as most ISDN net-
works allow CPE devices to initiate a LAPB link. If your ISDN network does not permit CPE
devices to initiate the LAPB link you should set this parameter to a value that allows the net-
work sufficient time to establish the LAPB link.