LANCOM 1722 VoIP – LANCOM 1724 VoIP
Chapter 5: Configuring Voice over IP
76
EN
The Call Router cannot find a 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.
The entry
in the call routing table depicted above matches the number
dialed. The call router removes the '0' outside-line access prefix, com-
pletes the area code for the local telephone network and completes the
call to '0241 555 555' using the ISDN line.
The entry
in the call routing table is suitable here. 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.
Call routing procedure on incoming calls
For incoming calls, the telephone network exchange removes the prefix from
the number dialed (destination number). Therefore, the LANCOM only
receives the number itself, which may be treated differently depending on the
source:
Numbers from the ISDN network are translated with the ISDN mapping
table to the internal number which is entered for the receiving MSN.
Calls from a SIP network are converted to the internal destination number
that is entered for the respective SIP line.
For call routing, not just the users configured in the LANCOM, but all of the users that are actu-
ally registered on the Call Router are used. The SIP users can register themselves as long as
they are not entered in the in the LANCOM. The entry for the internal VoIP domain on the
LANCOM is sufficient for registration, assuming that local authentication is not required.
The area code for the local telephone network is added on because calls via SIP providers usu-
ally require the area code to be dialed.
