LANCOM 1722 VoIP – LANCOM 1724 VoIP
Chapter 5: Configuring Voice over IP
92
EN
routing table. Therefore, the call router searches the local user list, finds
the correct entry there and can forward the call internally.
Internal call between a VoIP terminal device at the branch office and the
internal subscriber '199' at the headquarters. The number dialed, '199',
does not match any of the routes listed in the call routing table during the
first pass. Similarly, no matching entry can be found in the local user list.
In the second pass through the call routing table, the standard routes are
considered too. The route with the number called '#'
corresponds to
all calls which could not be assigned earlier. The call to '199' is therefore
carried out over the SIP PBX line.
External call from the branch office into the local telephone network. The
number dialed, '0 555,555', matches the route '0#'
in the call routing
table. The call router removes the '0' outside-line access prefix, completes
the area code for the local telephone network and completes the call to
'0241 555 555' using the ISDN line.
External call from the branch office into a national telephone network. The
number dialed, '0 0123 555 555', matches the route '00#'
in the call
routing table. The call router sends the call out to the SIP PBX line
unchanged
. Only now does the SIP PBX removes the '0' outside-line
access prefix and completes the call to '0123 555 555' via the ISDN out-
side line.
5.2.5
VoIP coupling for locations without a SIP PBX
Companies with widely disperse offices and without their own SIP PBX can
also take advantage of VoIP site coupling. In this "Peer-to-Peer" scenario, a
LANCOM VoIP Router has been implemented at both locations.