AI2524 Router Card User’s Manual
Page 12-4 August 1997
2524UM
used to prevent one side from monopolizing the virtual circuits, and is
useful for X.25 interfaces with a small total number of SVCs available.
Six X.25 parameters define the upper and lower limit of each of th
three SVC ranges. A PVC must be assigned a number less than the
numbers assigned to the SVC ranges. An SVC range is not allowed to
overlap another range.
Note: Because the X.25 protocol requires the DTE and DCE to
have identical virtual circuit ranges, changes you make to
the virtual circuit range limits when the interface is up are
held until the X.25 protocol restarts the packet service.
To configure X.25 virtual circuit ranges, complete these tasks as ap-
propriate for your configuration:
1. Set the lowest incoming-only circuit number (default is 0).
x25 lic
circuit-number
2. Set the highest incoming-only circuit number (default is 0).
x25 hic
circuit-number
3. Set the lowest two-way circuit number (default is 1).
x25 ltc
circuit-number
4. Set the highest two-way circuit numbe r (default is1024 for X.25
and 4095 for CMNS).
x25 htc
circuit-number
5. Set the lowest outgoing-only circuit number (default is 0).
x25 loc
circuit-number
6. Set the highest outgoing-only circuit number (default is 0).
x25 hoc
circuit-number
Each of these parameters can range from 1 to 4095, inclusive. The val-
ues for these parameters must be the same on both ends of an X.25
link. For connection to a PDN, these values must be set to the values
assigned by the network. Virtual circuit 0 is not available except for
marking unused ranges (by setting the lower and upper limits to 0).
Example: Virtual Circuit Ranges
This example sets the virtual circuit ranges of 5 to 20 for incoming
calls only (from the DCE to the DTE) and 25 to 1024 for either incom-
ing or outgoing calls. It also specifies no virtual circuits for outgoing
calls (from the DTE to the DCE). Up to 4 permanent virtual circuits
can be defined on virtual circuits 1 through 4.