Cisco 6800 Series Administration Manual page 298

Proxy and Registration
Parameter
Alternate Proxy
Alternate Outbound Proxy
Use OB Proxy In Dialog
Register
Make Call Without Reg
Cisco IP Phone 6800 Series Multiplatform Phones Administration Guide
284
Description
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
Phone Troubleshooting