Yealink CP860 [245/417] Phone configuration for redundancy implementation

Configuring Advanced Features

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Two types of redundancy are possible. In some cases, a combination of the two may be

deployed:

 Failover: In this mode, the full phone system functionality is preserved by having a

second equivalent capability call server take over from the one that has gone

down/off-line. This mode of operation should be done using the DNS mechanisms

from the primary to the secondary server.

 Fallback: In this mode, a second less featured call server (fallback server) with SIP

capability takes over call control to provide basic calling capability, but without

some advanced features (for example, shared lines, MWI) offered by the working

server. IP phones support configuration of two SIP servers per SIP registration for

fallback purpose.

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 as below. In the example, server redundancy for

fallback and failover purposes is deployed. Two separate SIP servers (a working server

and a fallback server) are configured for per line registration.

Working Server: Server 1 is configured with the domain name of the working server. For

example, yealink.pbx.com. DNS mechanism is used such that the working server is

resolved to multiple physical SIP servers for failover purpose. The working server is

deployed in redundant pairs, designated as primary and secondary servers. The

primary server is the highest priority server in a cluster of servers resolved by the DNS

server. The secondary server backs up a primary server when the primary server fails

and offers the same functionality as the primary server.

Fallback Server: Server 2 is configured with the address of the fallback server. For

example, 192.168.1.15. A fallback server offers less functionality than the working server.