Multiple Registrars on SIP Trunks

Last Updated: December 20, 2011

The Support for Multiple Registrars on SIP Trunks on a Cisco Unified Border Element, on Cisco IOS SIP TDM Gateways, and on a Cisco Unified Communications Manager Express feature allows configuration of multiple registrars on Session Initiation Protocol (SIP) trunks, each simultaneously registered using its respective authentication instance. Beginning with Cisco IOS XE Release 3.1S, support for this feature is expanded to include the Cisco ASR 1000 Series Router. This feature allows a redundant registrar for each of the SIP trunks, which provides SIP trunk redundancy across multiple service providers.

Finding Feature Information
Prerequisites for Multiple Registrars on SIP Trunks
Restrictions for Multiple Registrars on SIP Trunks
Configuring Multiple Registrars on SIP Trunks Feature
Feature Information for the Multiple Registrars on SIP Trunks Feature

Finding Feature Information

Your software release may not support all the features documented in this module. For the latest feature information and caveats, see the release notes for your platform and software release. To find information about the features documented in this module, and to see a list of the releases in which each feature is supported, see the Feature Information Table at the end of this document.

Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to www.cisco.com/go/cfn. An account on Cisco.com is not required.

Prerequisites for Multiple Registrars on SIP Trunks

Cisco Unified Border Element

Cisco IOS Release 15.0(1)XA or a later release must be installed and running on your Cisco Unified Border Element.

Cisco Unified Border Element (Enterprise)

Cisco IOS XE Release 3.1S or a later release must be installed and running on your Cisco ASR 1000 Series Router.

Restrictions for Multiple Registrars on SIP Trunks

The Support for Multiple Registrars on SIP trunks feature has the following restrictions:

Old and new forms of the registrar command are mutually exclusive: the registrar can be configured in either primary/secondary mode or multiple registrar mode--not both.
Dynamic Host Configuration Protocol (DHCP) support is not available with multiple registrars (available for primary/secondary mode only).
Only one authentication configuration per username can be configured at any one time.
A maximum of six registrars can be configured at any given time.
A maximum of 12 different realms can be configured for each endpoint.
You cannot restrict the registration of specific endpoints with specific registrars--once a new registrar is configured, all endpoints will begin registering to the new registrar.
You cannot remove multiple configurations of credentials simultaneously--only one credential can be removed at a time.

Configuring Multiple Registrars on SIP Trunks Feature

For information about the Support for Multiple Registrars on SIP Trunks feature and for detailed procedures for enabling this feature, see the "Configuring Multiple Registrars on SIP Trunks" chapter of the Cisco IOS SIP Configuration Guide.

Feature Information for the Multiple Registrars on SIP Trunks Feature

The following table provides release information about the feature or features described in this module. This table lists only the software release that introduced support for a given feature in a given software release train. Unless noted otherwise, subsequent releases of that software release train also support that feature.

Feature History Table entry for the Cisco Unified Border Element.

Table 1

Feature Information for the Multiple Registrars on SIP Trunks Feature

Feature Name

Releases

Feature Information

Multiple Registrars on SIP Trunks

15.0(1)XA 15.1(1)T

This feature provides support for multiple registrars on SIP trunks on Cisco IOS SIP TDM gateways, Cisco Unified CME, and Cisco UBEs. This feature allows for a redundant registrar for each SIP trunk and enables registrar redundancy across multiple service providers.

This feature includes the following new or modified commands: credentials, localhost, registrar, voice-class sip localhost.

Feature History Table entry for the Cisco Unified Border Element (Enterprise) .

Table 2

Feature Information for the Multiple Registrars on SIP Trunks Feature

Feature Name

Releases

Feature Information

Multiple Registrars on SIP Trunks

Cisco IOS XE Release 3.1S

This feature includes the following new or modified commands: credentials, localhost, registrar, voice-class sip localhost.

Cisco and the Cisco logo are trademarks or registered trademarks of Cisco and/or its affiliates in the U.S. and other countries. To view a list of Cisco trademarks, go to this URL: www.cisco.com/go/trademarks. Third-party trademarks mentioned are the property of their respective owners. The use of the word partner does not imply a partnership relationship between Cisco and any other company. (1110R)

Any Internet Protocol (IP) addresses and phone numbers used in this document are not intended to be actual addresses and phone numbers. Any examples, command display output, network topology diagrams, and other figures included in the document are shown for illustrative purposes only. Any use of actual IP addresses or phone numbers in illustrative content is unintentional and coincidental.