Installation guide

Synapse Installation Guide Back to Contents
Installation 12
System Installation Overview for Remote Sites
If two separate Synapse systems both have SIP Gateways, then they can communicate
with each other as “Remote Sites” on a privately managed network. Remote Sites allow
users to make extension-to-extension calls between Synapse sites, thus avoiding
long-distance charges. Users can also call external numbers at a Remote Site by routing
a call through a remote Gateway, thereby completing a long-distance call as a local call.
To use Remote Sites, you must set up a dedicated router-to-router Virtual Private
Network (VPN) between each site. This type of installation requires the following at each
site:
 A router that supports simultaneous VPNs and IPsec. AT&T recommends using
IPsec VPN.
 A static Wide Area Network (WAN) IP address at both sites
 Each Synapse site should be on a different LAN subnet.
See also “SIP Gateway Static IP Configuration” on page 16.
Configuring Remote Sites requires some coordination between the system administrators
for each site. To configure Remote Sites, you must configure one Remote Site SIP
Account for every other remote site. For more information, see “Configuring Remote
Sites” in the Synapse Administrator‘s Guide at
www.telephones.att.com/synapseguides.
Figure 4. Example of Remote Site Installation
Ensure that you configure the VPN to allow communication between the
two SIP Gateways by entering each Gateway’s private IP address into the
VPN setup.