D-Link DI-1750 Reference Manual page 77

5.5.5 Set the X.25 mode
A router using X.25 Level 3 encapsulation can act as a DTE or DCE protocol device (according to the
needs of your X.25 service supplier)
To configure the mode of operation and one of these encapsulation types for a specified interface,
perform the following task in interface configuration mode:
Command
x25 interface [dte|dce]
Key Word:
Q(quit)
......
(29)snmp
(30)x25
Please Input the code of command to be excute(0-30): 30
Key Word:
U(undo) D(default)
......
(09)interface
(10)k
......
Please Input the code of command to be excute(0-26): 9
Key Word:
Q(quit)
(00)dte
(01)dce
Please Input the code of command to be excute(0-1): 1
Will you excute it? (Y/N):y
For an example of configuring X.25 DTE operation, see the section "Typical X.25 Configuration
Example" later in this chapter.
5.5.6 Set the virtual circuit ranges
The X.25 protocol maintains multiple connections over one physical link between a DTE and a DCE.
These connections are called virtual circuits or logical channels (LCs). X.25 can maintain up to 4095
virtual circuits numbered 1 through 4095. You identify an individual virtual circuit by giving its logical
channel identifier (LCI) or virtual circuit number (VCN). Many documents use the terms virtual circuit
and LC, VCN, LCN, and LCI interchangeably. Each of these terms refers to the virtual circuit number.
An important part of X.25 operation is the range of virtual circuit numbers. Virtual circuit numbers are
broken into two ranges (listed here in numerically increasing order):
(3) Permanent virtual circuits (PVC)
(4) Switched virtual circuits (SVC)
The switched virtual circuit (SVC) can be established by the placement of an X.25 call, much like a
telephone network establishes a switched voice circuit when a call is placed.
Notes:
The ITU-T Recommendation X.25 defines "incoming" and "outgoing" in relation to the DTE or DCE interface role; D-LINK's
documentation uses the more intuitive sense. Unless the ITU-T sense is explicitly referenced, a call received from the
interface is an incoming call and a call sent out the interface is an outgoing call .)
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 the following tasks as appropriate for your
configuration:
Command
Model Name
Set the X.25 mode.
Modify SNMP interface parameters
Set parameters for X.25
Q(quit)
Set X.25 interface mode(DTE/DCE)
Set LAPB window size
Set local to DTE
Set local to DCE
function
Purpose
Range
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