- Enterasys Security Router User's Guide

Answering Incoming ISDN Calls
10-20 Configuring Dialer Services
Caveat
The following caveat applies to Dialer Watch functionality:
The dialer will not disconnect the secondary backup switched link if this connection has a better
cost to the watched route than the primary link. But, you can remedy this situation by entering the
ip rip offset command. Adding an offset on an interface makes it a backup port.
Answering Incoming ISDN Calls
The XSR handles incoming ISDN calls as follows:
• Always accepts incoming calls.
• If there is only one dialer interface configured it will bind the incoming call to that interface.
• If there is more than one dialer interface configured, the XSR will attempt to map the
incoming call to only one of these interfaces based on any of the following data passed by the
ISDN switch:
–Called number
– Calling number
• Mapping based on the called number is performed if the following conditions are met:
– The ISDN switch passes called number data to the XSR. Note that not all types of switches
can provide this information.
– The called number is configured under the target dialer interface using the
dialer
called
command.
• Mapping based on the calling number is performed if the following conditions are met:
– The ISDN switch passes the calling number to the XSR data. Note that not all types of
switches can provide this information.
– The calling number is configured under the target dialer interface using the
dialer
caller
command.
• Incoming calls may be mapped to a dialer interface based on the PPP authenticated username
if the following conditions are met:
– The username must be configured under the dialer interface using the
dialer remote-
name
command.
– Interface dialer 0 is configured with the desired PPP authentication (e.g.,
ppp
authentication pap
).
• In the case where a dialer interface is configured for multipoint operation using the
dialer
map
command, incoming calls are mapped based on the calling number matching the dialer
string set by the map or on the PPP authenticated username matching the name set by the
dialer map command.
• In the case where no dialer interface is found using the methods described above, the XSR will
display a high severity alarm stating cannot bind inbound call and will disconnect the ISDN call.