User`s guide

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X.25 PVCs
Configuration – Network > Legacy Protocol > X.25> X.25 PVCs
A Permanent Virtual Circuit (PVC) provides the X.25 equivalent of a leased line service. With
a PVC there is no call setup or disconnect process; you can just start sending and receiving
X.25 data on a specified LCN. For each X.25 service connection you may setup up multiple
PVCs each of which uses a different LCN (or a mixture of PVCs and SVCs). Digi routers
support up to four PVCs numbered 0-3.
X.25 PVC n
Configuration – Network > Legacy Protocol > X.25> X.25 PVCs> X.25 PVC n
Enable this PVC
Enables or disables the PVC.
LCN
This is the LCN value to be used for this PVC. In the case of an XOT PVC, this parameter
defines the Responder LCN field in the PVC setup packet (though an LCN of 1 is always used
in the XOT PVC connection). So for an XOT PVC this field should contain the remote
connections LCN.
PVC Mode
This parameter defines the lower layer interface to be used for the PVC and can be set to
“LAPB”, “LAPD” or “TCP” (for XOT mode).
Connect this PVC to PAD x
This parameter defines what type of upper layer interface is connected to this PVC and can
be set to “PAD” (for an X.25 PAD), “TPAD” (for a TPAD instance) or “XSW” (for X.25
switching). Note that if set to “XSW” (for the X.25 switch) then the X.25 switch will need to
also be configured regarding the interfaces to switch this PVC to/from. For example, if this is
an incoming XOT PVC we are configuring then the Switch from XOT PVC parameter needs to
be set to the desired destination interface.
Use packet size
This parameter defines the packet size to be used for the PVC. Select the appropriate value
from the drop down list.
Use window size
This parameter defines the layer 3 window size to be used for the PVC. Select the
appropriate value from the drop down list.
Remote IP address
This is the IP address to be used for outgoing XOT calls.
Use the source IP address from interface x,y
This parameter defines which Ethernet or PPP interface to use for the source IP address.
Initiator interface
This parameter may be set to the name of the interface from which the PVC was initiated,
e.g. Serial 1. The initiator and responder strings are used to identify the circuit when PVCs
are being set up. They must match the names in the remote unit that terminates the XOT
PVC connection. If the unit terminating the PVC XOT connection is not another Digi unit then
you need to refer to the documentation or the configuration files of the other unit to
determine the names of the interfaces.
Responder interface