Outgoing Trunk Group ID and Carrier ID for H.323 VoIP Networks

Table Of Contents

Outgoing Trunk Group ID and Carrier ID for H.323 VoIP Networks

Feature Overview

Benefits

Restrictions

Related Features and Technologies

Related Documents

Supported Platforms

Supported Standards, MIBs, and RFCs

Prerequisites

Configuration Tasks

Configuration Examples

Command Reference

Outgoing Trunk Group ID and Carrier ID for H.323 VoIP Networks

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Feature History

Release	Modification
12.2(2)XU	This feature was introduced.

This document describes the Outgoing Trunk Group ID and Carrier ID for H.323 VoIP Networks feature in Cisco IOS Release 12.2(2)XU. It includes the following sections:

•Feature Overview

•Supported Platforms

•Supported Standards, MIBs, and RFCs

•Prerequisites

•Configuration Tasks

•Configuration Examples

•Command Reference

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Note This document describes only outgoing trunk group ID and carrier ID support for alternate endpoints. Gatekeeper trunk- and carrier-based routing enhancements will be more fully addressed in a future release.

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Feature Overview

The Outgoing Trunk Group ID and Carrier ID for H.323 VoIP Networks feature provides an enhancement to Registration, Admission, and Status (RAS) Admission Confirmation and Location Confirm messages. RAS messages now include a circuitInfo field that provides trunk group label or carrier ID information for remote endpoints (gateways) in H.323 networks. This feature also adds trunk group label and carrier ID support for the alternate endpoint field in the Gatekeeper Transaction Message Protocol (GKTMP) Response Admission Request (ARQ), Admission Confirmation (ACF), Location Request (LRQ), and Location Confirm (LCF) messages.

This feature allows a gatekeeper to specify a primary route-server trunk group as the destination to which a call is to be routed. The gatekeeper provides the IP address of the terminating gateway and the trunk group label or carrier ID of that gateway (in the circuitInfo field) to the requesting gateway. The GKTMP application server provides the trunk group label or carrier ID of the terminating gateway to the gatekeeper in the Response ARQ, ACF, LRQ, or LCF messages. The gatekeeper converts the trunk group ID or carrier ID information and sends it in the circuitInfo field of its RAS message to the requesting gateway.

The GKTMP application server may also provide a list of alternate gateways in the Response ARQ, ACF, LRQ, or LCF messages that the gatekeeper sends to the requesting gateway. The alternate gateway list includes a separate call signal address and circuitInfo field (trunk group label or carrier ID) for each alternate gateway. The gatekeeper removes identical alternate gateway routes from the consolidated alternate gateway list before sending the list to the requesting gateway.

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Note The gatekeeper does not validate whether the alternate gateway is valid or whether the target carrier ID will have enough capacity if the destination gateways and their trunk group labels and carrier IDs are registered to the local gatekeeper zone.

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Figure 1 illustrates that this feature allows the gatekeeper in Zone 1 to receive routing information from the primary gateway, Gateway 2 in Zone 2, and from the alternate gateway, Gateway 3, also in Zone 2. The routing information is passed from the gatekeeper in Zone 1 to requesting Gateway 1.

Figure 1 Topology of Routing Between Zone 1 and Zone 2

The RAS message includes a new field called circuitInfo. The information in the circuitInfo field corresponds to the information in the new Q and J tags in the GKTMP message. The trunk group label (Q tag) or carrier ID (J tag) of the primary gateway is provided in the alternateEndpoint structure of the GKTMP message, along with the call signal address of the primary gateway. The trunk group label or carrier ID of each alternate gateway is also provided in the alternateEndpoint structure of the GKTMP message. The Q and J tags of each alternate gateway are embedded inside the existing A-tagged fields of the GKTMP message, as shown in the following example:

A=c:{I:172.18.194.1:1720} J:CARRIER_ID

A=c:{I:10.1.1.1:1720}   Q:TRUNK_GROUP_LABEL

The following is an example of a RAS message from a gatekeeper to a requesting gateway. (The gatekeeper has converted the information in the Q and J fields of the GKTMP message that it received from the GKTMP application server.) The RAS message contains two alternate endpoints, each of which has a circuitInfo field:

alternateEndpoints

 callSignalAddress

  ipAddress :

   'AC12C826'H

   port 1720

  circuitInfo

   destinationCircuitID

    group

     group "CARRIER_ID"

!

 callSignalAddress

  ipAddress :

   ip 'AC12C816'H

   port 1720

  circuitInfo

   destinationCircuitID

    group

     group "TRUNK_GROUP_LABEL"

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Note There are no new configuration tasks associated with this feature.

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Benefits

The gatekeeper can now send distinct circuit information for each alternate endpoint in the RAS ACF and LCF message, providing the gateway with more routing choices.

Restrictions

•Support for the alternate endpoint trunk group label is applicable only if both the gatekeeper and gateway in the originating network support the optional circuit information parameter discussed in the Alternate Endpoint Abstract of the International Telecommunication Union Telecommunication Standardization Sector (ITU-T) H.323, Version 5, specification.

•Cisco IOS Release 12.2(2)XU supports only Voice over IP (VoIP).

•Cisco IOS Release 12.2(2)XU does not support the Location Confirmation Enhancements for Alternate Endpoints feature in Cisco IOS Release 12.2(4)T.

Related Features and Technologies

•Cisco VoIP

•H.323 on Cisco gateways

Related Documents

The following documents are available from the Cisco.com website:

•The "Configuring H.323 Gatekeepers and Proxies" chapter in the Cisco IOS Voice, Video, and Fax Configuration Guide, Release 12.2

•Cisco IOS Voice, Video, and Fax Command Reference, Release 12.2

•Cisco H.323 Version 2 Phase 2

•Cisco High-Performance Gatekeeper

•Cisco Gatekeeper External Interface Reference, Version 3

•Cisco H.323 Scalability and Interoperability Enhancements

Supported Platforms

Gateway

•Cisco AS5300

•Cisco AS5350

•Cisco AS5400

Gatekeeper

•Cisco 2600 series

•Cisco 3660

•Cisco 7200 series

Supported Standards, MIBs, and RFCs

Standards

Cisco has submitted the following contribution to the ITU-T to add a new element in the Endpoint structure to forward circuit information for each alternate endpoint returned by the gatekeeper in the ACF message: "ITU-T SG16 Contribution AVD-2103: Circuit Information Signalling for Alternate Endpoints."

MIBs

No new or modified MIBs are supported by this feature.

To obtain lists of supported MIBs by platform and Cisco IOS release, and to download MIB modules, go to the Cisco MIB website on Cisco.com at the following URL:

http://www.cisco.com/public/sw-center/netmgmt/cmtk/mibs.shtml

RFCs

No new or modified RFCs are supported by this feature.

Prerequisites

•Configure VoIP. For more information about configuring VoIP, see the "Related Documents" section.

•Configure H.323 gatekeepers, gateways, and proxies as needed, including dial peers. For more information about configuring these H.323 components, see the "Related Documents" section.

•Configure local and remote zones on the Cisco IOS gatekeeper.

Configuration Tasks

None

Configuration Examples

None

Command Reference

None