Cisco Ip Phone 8800 Series Multiplatform Phones Administration Guide - Cisco 8851 Administration Manual

Parameter
Outbound Proxy
Alternate Proxy
Alternate Outbound Proxy
Use OB Proxy In Dialog
Register
Make Call Without Reg
Register Expires
Description
All outbound requests are sent as the first hop. Enter an IP address or
domain name.
This feature provides fast fall back when there is network partition at
the Internet or when the primary proxy (or primary outbound proxy) is
not responsive or available. The feature works well in a Verizon
deployment environment as the alternate proxy is the Integrated Service
Router (ISR) with analog outbound phone connection.
Enter the proxy server addresses and port numbers in these fields. After
the phone is registered to the primary proxy and the alternate proxy (or
primary outbound proxy and alternate outbound proxy), the phone
always sends out INVITE and Non-INVITE SIP messages (except
registration) via the primary proxy. The phone always registers to both
the primary and alternate proxies. If there is no response from the
primary proxy after timeout (per the SIP RFC spec) for a new INVITE,
the phone attempts to connect with the alternate proxy. The phone
always tries the primary proxy first, and immediately tries the alternate
proxy if the primary is unreachable.
Active transactions (calls) never fall back between the primary and
alternate proxies. If there is fall back for a new INVITE, the
subscribe/notify transaction will fall back accordingly so that the phone's
state can be maintained properly. You must also set Dual Registration
in the Proxy and Registration section to Yes.
Determines whether to force SIP requests to be sent to the outbound
proxy within a dialog. Ignored if the Use Outbound Proxy field is set
to No or if the Outbound Proxy field is empty.
Default: Yes
Enables periodic registration with the proxy. This parameter is ignored
if a proxy is not specified. To enable this feature, select Yes.
Default: Yes
Enables making outbound calls without successful (dynamic) registration
by the phone. If set to No, the dial tone plays only when registration is
successful. To enable this feature, select Yes.
Default: No
Defines how often the phone renews registration with the proxy. If the
proxy responds to a REGISTER with a lower expires value, the phone
renews registration based on that lower value instead of the configured
value.
If registration fails with an "Expires too brief" error response, the phone
retries with the value specified in the Min-Expires header of the error.
The range is from 32 to 2000000.
Default: 3600 seconds

Cisco IP Phone 8800 Series Multiplatform Phones Administration Guide

Cisco IP Phone Web Page
261