Polycom SIP 2.2.0 Phone Configuration, Reg.1.server.1.address=voipserver.serviceprovider.com

Administrator’s Guide SoundPoint IP / SoundStation IP

Warning If DNS is used to resolve the address for Servers, the DNS server is unavailable, and the TTL for the DNS records has expired, the phone will attempt to contact the DNS server to resolve the address of all servers in its list before initiating a call. These attempts will timeout, but the timeout mechanism can cause long delays (for example, two minutes) before the phone call proceeds “using the working server”. To mitigate this issue, long TTLs should be used. It is strongly recommended that an on-site DNS server is deployed as part of the redundancy solution.

Hosted VoIP Service

Provider

Call Server 1B

Call Server 1A

DNS Server

Internet

PSTN

Phone Configuration

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

The phones at the customer site are configured as follows:

•Server 1 (the primary server) will be configured with the address of the service provider call server. The IP address of the server(s) to be used will be provided by the DNS server. For example:

reg.1.server.1.address="voipserver.serviceprovider.com"

•Server 2 (the fallback server) will be configured to the address of the router/gateway that provides the fallback telephony support and is on-site. For example:

reg.1.server.2.address=172.23.0.1

Note	It is possible to configure the phone for more than two servers per registration, but
	you need to exercise caution when doing this to ensure that the phone and network
	load generated by registration refresh of multiple registrations do not become
	excessive. This would be of particularly concern if a phone had multiple
	registrations with multiple servers per registration and it is expected that some of
	these servers will be unavailable.

4 - 36