Lancom 1723 VOIP User Manual page 19

LANCOM 1722 VoIP – LANCOM 1723 VoIP – LANCOM 1724 VoIP – LANCOM 1823 VoIP
Chapter 1: Introduction
codes to decide upon the switching of a call either via the ISDN interface, or
via the Internet as a VoIP call.
Connecting subsidiaries or home offices to the headquarters
Many subsidiaries or home offices already have a connection to the network
at headquarters over VPN. These connections are normally limited to conven-
tional data transmission. By using VoIP, internal company calls can be made
for free over the existing VPN connection and— thanks to the VPN
encryption —these calls are secured against eavesdropping.
With a LANCOM VoIP Router located in the branch or home office, the two
worlds of traditional (ISDN and analog) and VoIP telephony can be united in
a single telephone: A SIP telephone or an existing analog or ISDN telephone
can be used for free telephone calls via VPN to the headquarters, or to make
standard calls via the conventional telephone network.
Example: Branch office with analog telephone connection, headquarters with SIP- capable PBX
PC / Softphone
POTS
Analog Phone
Branch office
The advantages of a telephone connection to headquarters:
18
SIP Phone
INTERNET
VoIP Router
PSTN
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.
SIP Phone
VoIP Router
PC
Headquarters
SIP Phone SIP Phone
PBX PC