LANCOM 1722 VoIP – LANCOM 1723 VoIP – LANCOM 1724 VoIP – LANCOM 1823 VoIP
Chapter 1: Introduction
17
EN
Telephone calls over the PBX and the telephones connected to it remain pos-
sible just as before; the telephones remain available under the familiar tele-
phone numbers. This application additionally offers the following options:
In addition to the ISDN and analog telephones, SIP telephones or SIP soft-
phones can be included in the telephone infrastructure.
SIP subscribers in the internal LAN are also able to call external PSTN
subscribers.
The ISDN and analog telephones continue to function, and addition-
ally they can call all of the internal SIP telephones and softphones in
the LAN.
Calls to external SIP subscribers who use the same Internet provider are
often available at no cost.
With the appropriate connection to a public SIP provider, other SIP sub-
scribers worldwide can be called. As an alternative to a direct telephone
connection, public telephone network subscribers can also be reached
over a diversion via the SIP provider. The costs depend on the provider's
particular tariff models. Frequently, long-distance and overseas calls via
an SIP provider are significantly cheaper than the traditional telephone
connection.
In this constellation, the LANCOM VoIP Router takes over the switching of the
calls. The device can be individually configured, for example, to use the access
VOIP Router
Analog FAX
PC / Softphone
SIP Phone
PC / Softphone
INTERNET
SIP Server
SIP Phone
ISDN
NTBA
ISDN Phone
ISDN
ISDN Phone
ISDN
PBX
Example: ISDN PBX
