Limitations For Dual Registration And Dns Srv Redundancy; Alternate Proxy And Dual Registration; Register Upon Failover/Recovery; Fallback Behavior - Cisco 8831 Administration Manual

Chapter 3 Configure SIP and NAT

Limitations for Dual Registration and DNS SRV Redundancy

The limitations for Dual Registration and DNS SRV redundancy are as follows:
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Alternate Proxy and Dual Registration

When the Dual Register parameter is set to No, Alternate Proxy is ignored.

Register Upon Failover/Recovery

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Fallback Behavior

The fallback occurs when the current registration expires or Proxy Fallback Intvl fires.
If the Proxy Fallback Intvl exceeds, all the new SIP messages go to primary proxy.
For example, when the value for Register Expires is 3600 seconds and Proxy Fallback Intvl is 600
seconds, the fallback is triggered 600 seconds later.
When the value for Register Expires is 800 seconds and Proxy Fallback Intvl is 1000 seconds, the
fallback is triggered at 800 seconds.
After successfully registering back to primary server, all the SIP messages go to primary server.

RFC3261 Support

The Cisco Unified IP Conference Phone 8831 for Third-Party Call Control supports RFC-3261, the SIP
UPDATE Method.

Support for SIP NOTIFY XML-Service

The Cisco Unified IP Conference Phone 8831 for Third-Party Call Control support the SIP NOTIFY
XML-Service event. On receipt of a SIP NOTIFY message with an XML-Service event, the phone
challenges the NOTIFY with a 401 response if the message does not contain correct credentials. The
client must be furnish the correct credentials using MD5 digest with the SIP account password for the
corresponding line of the IP phone.
The body of the message can contain the XML event Message. For example:
<CiscoIPPhoneExecute>
When Dual Registration is enabled, DNS SRV Proxy Fallback/Recovery must be disabled.
Do not use Dual Registration in conjunction with other Fallback/Recovery mechanisms. For
example: Broadsoft mechanism.
There is no recovery mechanism for feature request. However, the administrator can adjust the
re-registration time for a prompt update of the registration state for primary and alternate proxy.
Failover—The phone performs a failover to secondary proxy when the SIP request gets no response
from primary proxy.
Recovery—The phone attempts to re-register with the primary proxy while registered or actively
connected to the secondary proxy.
Cisco Unified IP Conference Phone 8831 for Third-Party Call Control Administration Guide
SIP and Cisco Unified IP Conference Phone 8831 for Third-Party Call Control
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