Installation guide

Synapse Installation Guide Back to Contents
Installation 12
System Installation Overview for Remote Sites
If Synapse systems on different LAN subnets have SIP Gateways installed, then they can
communicate with each other as “Remote Sites” on a Virtual Private Network (VPN).
Remote Sites allow users to make extension-to-extension calls between Synapse sites
over the VPN, 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 VPN between each
site. This type of installation requires the following at each site:
 A router that supports simultaneous VPNs and IPsec.
 A static Wide Area Network (WAN) IP address at both sites
See also “SIP Gateway Static IP Configuration” on page 15.
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 3. 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. We recommend using IPsec VPN.