E V E R Y C A L L C O U N T S
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MULTI-BRANCH VOIP NETWORK
A multi-branch VoIP network has at least one SIP device at each location. A SIP device is a VoIP-
enabled phone system, IP telephone or SIP gateway. One phone system in the network acts as the SIP
server. The other SIP devices are SIP clients.
A user, auto attendant or call cascade can dial a VoIP number to reach an extension, auto attendant
or voice mailbox at any location.
For example, the following illustration shows a multi-branch VoIP network with two locations. Calls
between the offices are routed over the Internet, and local calls are routed over the traditional
telephone network.
Figure 3: Multi-branch VoIP network
Five VoIP numbers are assigned to San Francisco (351 to 355), and nine are assigned to New York
(361 to 369). These VoIP numbers can be dialed directly from any extension, auto attendant or call
cascade in the network.
The phone system in the San Francisco office has a static public IP address, so is designated as the
SIP server. The phone system in New York is a SIP client.
VoIP location numbers should have the number of digits specified in your numbering plan for maximum
functionality (3, 4 or 5 digits). All units in the VoIP network should have the same dialing plan.
Before proceeding, ensure you have:
•
Connected the system at each location to a network (see page 2).
•
Configured local and public IP addresses (page 3).
•
Configured the router (page 6).
