User guide

Chapter 1: Description & Specifications
Multi-Tech Systems, Inc. MVPGSM 5
As a Survivable SIP Server:
In this mode the MVPGSM functions as a Back to Back User Agent (B2BUA) and routes SIP registration and call
control packets between the SIP endpoints and Primary proxy. The MVPGSM monitors the status of the primary
proxy and, if the primary proxy is unavailable, the MVPGSM functions as a SIP server and takes over the routing
of calls between SIP endpoints. When the network connection to the primary SIP proxy is restored, the
MVPGSM resumes routing registration and call processing packets to the Primary SIP Proxy. SIP endpoints must
be configured to use the MVPGSM as their proxy. On the MVPGSM, the SIP Server and Use Proxy options must
be enabled. Predefined endpoints should be configured in the MVPGSM SIP Server so that the MVPGSM has the
authentication information needed for re-registering SIP endpoints to the primary proxy.