beautypg.com

Server redundancy, Server redundancy –34, Server – Polycom SOUNDPOINT SIP 2.2.0 User Manual

Page 82

background image

Administrator’s Guide SoundPoint IP / SoundStation IP

4 - 34

Server Redundancy

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.

For more information, refer to “Technical Bulletin 5844: SIP Server Fallback

Enhancements on SoundPoint IP Phones” at

http://www.polycom.com/support/voice/

.

Configuration changes can performed centrally at the boot server:

Note

Your SIP server provider should be consulted for recommended methods of
configuring phones and servers for fail-over configuration.

Warning

Prior to SIP 2.1, the reg.x.server.y parameters (refer to

Registration

on

page

A-84

) 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).

Central

(boot server)

Configuration file:
sip.cfg

Specify global primary and fallback server configuration parameters.

For more information, refer to

Protocol

on page

A-6

.

Configuration file:
phone1.cfg

Specify per registration primary and fallback server configuration
parameters values that override those in sip.cfg.

For more information, refer to

Registration

on page

A-84

.