You can configure a dialer interface to accept all incoming calls or accept only calls from one or more caller IDs.
If the dialer interface is configured to accept only calls from a specific caller ID, the Services Router matches the incoming call's caller ID against the caller IDs configured on its dialer interfaces. If an exact match is not found and the incoming call's caller ID has more digits than the configured caller IDs, the Services Router performs a right-to-left match of the incoming call's caller ID with the configured caller IDs and accepts the incoming call if a match is found. For example, if the incoming call's caller ID is 4085321091 and the caller ID configured on a dialer interface is 5321091, the incoming call is accepted. Each dialer interface accepts calls from only callers whose caller IDs are configured on it.
To configure a dialer interface for USB modem dial-in:
Table 84: Configuring the Dialer Interface for USB Modem Dial-In