On outgoing calls, the Call Manager first searches the call routing table from top to bottom. If the Call Router cannot find a matching entry there, it uses the list of registered users:
| User | Dials | Correct call route | Correct user | Mapping, number in use | Destination line | |
|---|---|---|---|---|---|---|
| 1 | VoIP telephone | 11 | None | VoIP softphone | 11 | Internal |
| 2 | VoIP telephone | 0 555 555 | 3 0# | 0241#: 0241 555 555 | ISDN | |
| 3 | VoIP telephone | 0 0123 666 666 | 3 00# | 0#: 0123 666 666 | SIP provider |
- The Call Manager cannot find an entry that corresponds to 11 in the call routing table. Now it searches the list of registered users and finds the internal SIP user there.
Call routing uses not just the users configured in the LANCOM, but all of the users that are actually authorized with the call router. This allows SIP users to authenticate with the call router even if they are not entered in the LANCOM. The entry of the internal VoIP domain on the LANCOM is sufficient for authentication, assuming that local authentication is not required. - The entry 3 in the call routing table shown above matches the dialed number. The call router removes the 0 outside-line access prefix, adds the area code for the local telephone network and makes the call to 0241 555 555 via the ISDN line.
The area code for the local telephone network is added on because calls via SIP providers usually require the area code to be dialed. - The entry in the call routing table is suitable in this case. The call router removes the 0 prefix for access to the outside line and completes the call to 0123 555 555 via the SIP line. If the SIP line is not available, then the call is made over the ISDN line.
