Server-Gateway Mode
SARK can run in either of two modes; Server-Gateway or Server-Only.
Server-Gateway Mode
[ View a larger version of the server gateway network diagram ]
In Server-Gateway mode, SARK sits at the head of the network and acts as a firewall/router, Session Border Controller and local network manager providing DHCP, DNS and TFTP services to the local SIP community. Alternatively, it can serve as a SIP gateway/proxy in a high-speed shared data and voice network setup.
The primary benefit to running in Server-Gateway mode lies in the fact that the PBX efectively sits "at the firewall" allowing it to provide session border control and symmetrical RTP services to remotely attached SIP devices, even when they are running behind "NATted" firewalls. In practice, this means you can plug in a remote SIP phone or ATA almost anywhere and it will happily register with the SARK proxy.
Automatic provisioning of remote SIP phones and ATA's is handled through SARK's on board HTTP provisioning server.