Yealink T5 Series Administrator's Guide

Account Settings
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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.
l Fallback: In this mode, a second less featured call server with SIP capability takes over call control to provide basic
calling capability, but without some advanced features (for example, shared line and MWI) offered by the working
server. The phones support configuration of two servers per SIP registration for the fallback purpose.
Note
For concurrent registration mode, it has a certain limitation when using some advanced features, and for successive regis-
tration mode, the phone service may have a brief interrupt while the server fails. So we recommend you to use the failover
mode for server redundancy because this mode can ensure the continuity of the phone service and you can use all the call
features while 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 as below. In the example, server redundancy for fallback and failover purposes is deployed. Two separate serv-
ers (a working server and a fallback server) are configured for per line registration.
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l 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 servers with different IP addresses for
failover purpose. The working server is deployed in redundant pairs, designated as primary and secondary servers.
The primary server (for example, 192.168.1.13) has the highest priority server in a cluster of servers resolved by the
DNS server. The secondary server (for example, 192.168.1.14) backs up a primary server when the primary server fails
and offers the same functionality as the primary server.
l Fallback Server: Server 2 is configured with the IP address of the fallback server. For example, 192.168.1.15. A fall-
back server offers less functionality than the working server.
Yealink phones support Failover and Fallback server redundancy types. In some cases, you can deploy a combination
of the two server redundancy types. For more information on server redundancy, refer to Server Redundancy on
Yealink IP Phones.
Topics
Behaviors When Working Server Connection Fails

Yealink T5 Series Specifications

General

Brand	Yealink
Model	T5 Series
Category	IP Phone
Language	English