LANCOM 1722 VoIP – LANCOM 1724 VoIP
Chapter 1: Introduction
17
EN
The advantages of a telephone connection to headquarters:
The configuration of telephone functions can be carried out centrally in
the VoIP PBX at headquarters.
Subscribers at their branch or home offices connect with the central PBX.
Calls within the company network are free.
Outgoing calls are automatically directed to the optimal line for cost opti-
mization.
VoIP for companies through SIP trunking
One of the biggest hurdles for companies that fully migrate to VoIP is to main-
tain the existing telephone numbers. Normal provider SIP accounts come with
a telephone number for the transition to the landline telephone network, but
generally these numbers are selected from a pool of numbers available to the
provider. However, for companies with a large number of telephone subscrib-
ers and numbers, it is of decisive importance that existing telephone and
extension numbers are maintained after migrating to VoIP.
With the SIP trunking function, entire ranges of telephone numbers made up
of external numbers and their associated extensions can be mapped by
LANCOM VoIP Routers over a single connection to a SIP provider, assuming
that the provider also supports Direct Dialing In (DDI) and can provide multi-
ple connections simultaneously. Generally speaking, SIP providers that offer
SIP trunking can acquire the existing telephone numbers from the former tel-
ecomms provider.
LANCOM VoIP Router
Internet
ISDN
VoIP telephone
VoIP PBX connected to the
ISDN network
VPN tunnel
VoIP telephones
LANCOM
ISDN telephone
Branch office
Headquarters
