Westermo MR Series - Manual (Page 200)

200 6622-3201
Web Interface and Command Line Reference Guide www.westermo.com
Confi gure > PPP > PPP n > PPP/IP Over X25 4.62
Westermo routers can optionally support transmission of TCP/IP packets encapsulated in X.25. This
fea ture allows the ISDN D-channel to be used as an “always on” connection providing a permanent,
low speed Internet Protocol pipe between two Local Area Networks.
Using the Web Page(s)
These parameters are used when configuring PPP or IP over X.25.
Calling NUA:
This specifies the calling X.25 address to be used when using PPP or IP over X.25.
Default packet size:
This specifies the default X.25 packet size to use.
IP over X25 mode:
When set to “On”, this causes the unit to route IP data over X.25. Otherwise, PPP over X.25 is
used.
Layer 2 interface:
This parameter is used to select whether the PPP instance will use B or D-channel X.25. If
“None” is specified, then PPP/IP over X.25 mode is disabled.
Layer 2 interface #:
This parameter specifies which LAPB or LAPD instance to use for the relevant PPP instance.
LCN:
The LCN (Logical Channel Number) parameter is the value of the first LCN that will be
assigned for outgoing X.25 CALLs. The default is 1027.
LCN direction:
This parameter determines whether the LCN used for outgoing X.25 calls is incremented or
decre mented from the starting value when multiple X.25 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.
Restart delay (ms):
When the Restarts parameter is set to “On” the value specified in the Restart delay dialog box
determines the length of time in milliseconds that the unit will wait before issuing a Restart
packet. The default value is 2000 giving a delay of 2 seconds.
Restarts:
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”.