Server Redundancy - Polycom SIP 3.0.2 Administrator's Manual

Configuration file:
Central
sip.cfg
(boot server)
Configuration file:
phone1.cfg

Server Redundancy

Note
Warning
The phone also supports ACD agent available and unavailable. This feature
depends on support from a SIP server.
Configuration changes can performed centrally at the boot server:
Turn this feature on or off.
For more information, refer to
•
Enable this feature per registration.
For more information, refer to
•
Server redundancy is often required in VoIP deployments to ensure continuity
of phone service for events where the call server needs to be taken offline for
maintenance, the server fails, or the connection from the phone to the server
fails.
Two types of redundancy are possible:
• Fail-over: 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 DNS mechanisms or "IP Address Moving" from the primary to the
back-up server.
• Fallback: In this mode, a second less featured call server (router or
gateway device) with SIP capability takes over call control to provide basic
calling capability, but without some of the richer features offered by the
primary call server (for example, shared lines, presence, and Message
Waiting Indicator). Polycom phones support configuration of multiple
servers per SIP registration for this purpose.
In some cases, a combination of the two may be deployed.
Your SIP server provider should be consulted for recommended methods of
configuring phones and servers for fail-over configuration.
Prior to SIP 2.1, the reg.x.server.y parameters (refer to
page A-89) could be used for fail-over configuration. The older behavior is no longer
supported. Customers that are using the reg.x.server.y. configuration
parameters where y>=2 should take care to ensure that their current deployments
are not adversely affected. For example the phone will only support advanced SIP
features such as shared lines, missed calls, presence with the primary server (y=1).
For more information, refer to "Technical Bulletin 5844: SIP Server Fallback
Enhancements on SoundPoint IP Phones" at
http://www.polycom.com/support/voice/.
Configuring Your System
Feature <feature/> on page A-83.
Registration <reg/> on page A-89.
Registration <reg/> on
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