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Matrix SPARSH VP710 User Guide 593
Server Redundancy
Server redundancy is often required in VoIP deployments to ensure continuity of the phone service when the
connection between the IP phone and the server fails or the server fails and therefore the server needs to be taken
offline for maintenance.
Two types of redundancy are possible and in some cases, a combination of the two may be deployed:
• Failover: In this mode, the full phone functionality is preserved by having a secondary call server with
equivalent capability which takes over the server that has gone down/off-line.This mode of operation
should be done using the DNS mechanism from the primary to the secondary server. Therefore, if you
want to use this mode, the server must be configured with a domain name.
• Fallback: In this mode, a secondary less featured call server with SIP capability takes over the call control
to provide basic calling capability, but without some advanced features (for example, shared line and MWI)
offered by the working server. IP phone supports configuration of two servers per SIP registration for
fallback purpose.
• When using some advanced features in concurrent registration mode, the IP phone has certain
limitations and for successive registration mode, the phone service may have a brief interrupt when the
server fails. Therefore it is recommended to use failover mode for server redundancy as it ensure the
continuity of the phone service and allow accessing of all the call features when the server fails
.
Phone Configuration for Redundancy Implementation
To assist in explaining the redundancy behavior, an illustrative example of how an IP phone may be configured is
shown below.
In the example, server redundancy for fallback and failover purposes is deployed. Two separate servers (a working
server and a fallback server) are configured for per account (line) registration.