Polycom Version 2.0.3B manual SIP 2.1 Server Fallback Implementation, Example Deployment

Technical Bulletin

SoundPoint ® IP, SIP 2.1

SIP 2.1 Server Fallback Implementation

In the SIP 2.1 release, the redundancy behavior of Polycom SoundPoint IP and SoundStation IP phones has been changed and improved by adding the ability for a single SIP Registration (Line) to be registered to more than one server concurrently. In previous releases, the phone would only maintain one active server registration per SIP Registration (Line). The concurrent server registration capability adds an ability to do a faster and more efficient hand-over to an independent call server both for incoming as well as outgoing calls.

To assist in explaining the redundancy behavior, an illustrative example of how a system may be deployed is defined in the following section.

Example Deployment

A small medium business (SMB) customer uses a hosted IP-Centrex service from a Service provider. The Service provider has two redundant call servers at their network operations center (NOC) and uses a DNS server to resolve the IP addresses of these servers. The SMB customer also has an on-premise router which has the ability to handle SIP call traffic and has a connection to an on-site PSTN gateway. This gateway is intended to be used in conditions in which the Internet connection to the service provider is not working.

Hosted VoIP Service

Provider

Call Server 1B

Call Server 1A

DNS Server

PSTN

Internet

	VoIP SMB Customer
SIP Capable Router	Premise
Server2
	`
	`
PSTN Gateway
	`
	`

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