Cisco Unified Border Element with Gatekeeper Configuration Guide, Release 12.4T
Overview of Cisco Unified Border Element with Gatekeeper
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Overview of Cisco Unified Border Element with Gatekeeper

Table Of Contents

Overview of Cisco Unified Border Element with Gatekeeper

Contents

Prerequisites for Cisco Unified Border Element with Gatekeeper Configuration

Restrictions for Cisco Unified Border Element with Gatekeeper Configuration

Information About Cisco Unified Border Element with Gatekeeper

Gatekeeper Functionality

Cisco Unified Border Element with Gatekeeper Network Topology

Features Supported by the Cisco Unified Border Element with Gatekeeper

Gatekeeper Call-Signaling Features

Gatekeeper-Related Features

Interoperability Features

Additional References

Related Documents

Standards

MIBs

RFCs

Technical Assistance

Glossay


Overview of Cisco Unified Border Element with Gatekeeper


Revised: Month Day, Year,
First Published: June 19, 2006
Last Updated: July 11, 2008

This guide describes the Cisco Unified Border Element with Gatekeeper(Cisco UBE with Gatekeeper) and related features.


Activation Before you can configure the software features described in this guide, you will need a Product Authorization Key (PAK). Before you start the configuration process, please register your products and activate your PAK at the following URL http://www.cisco.com/go/license.


An Cisco Unified Border Element, in this guide called an Cisco UBE but sometimes elsewhere called an IP-to-IP Gateway, border element or session border controller, facilitates connectivity between independent VoIP networks by enabling H.323 VoIP and videoconferencing calls from one IP network to another. This gateway performs most of the same functions of a PSTN-to-IP gateway, but typically joins two IP call legs, rather than a PSTN and an IP call leg. Media packets can flow either through the gateway (thus hiding the networks from each other) or around the gateway, if so configured.

Cisco Unified Border Element with Gatekeeper is a special Cisco IOS software image that runs on Cisco multiservice gateway platforms. It provides a network-to-network interface point for billing, security, call admission control, quality of service, and signaling interworking.

Cisco Unified Border Element with Gatekeeper is designed to meet the interconnection needs of Internet telephony service providers (ITSPs) and of enterprises. One set of images provides basic interconnection and a second set provides interconnection through an Open Settlement Protocol (OSP) provider, enabling ITSPs to gain the benefits of the Cisco Unified Border Element with Gatekeeper while making use of the routing, billing, and settlement capabilities offered by OSP-based clearinghouses.

For the most effective and scalable results, use the Cisco Unified Border Element concurrently with a Cisco gatekeeper.

Feature history for the umbrella Cisco Unified Border Element with Gatekeeper suite of features is shown below. Individual feature histories are provided at the end of each chapter.

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 "Cisco Unified Border Element with Gatekeeper Features Roadmap" section on page 3.

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


Note For more information about Cisco IOS voice features, see the entire Cisco IOS Voice Configuration Library—including feature documents, and troubleshooting information—at http://www.cisco.com/en/US/docs/ios/12_3/vvf_c/cisco_ios_voice_configuration_library_glossary/
vcl.htm


Contents

Prerequisites for Cisco Unified Border Element with Gatekeeper Configuration

Restrictions for Cisco Unified Border Element with Gatekeeper Configuration

Information About Cisco Unified Border Element with Gatekeeper

Additional References

Prerequisites for Cisco Unified Border Element with Gatekeeper Configuration

Cisco Unified Border Element with Gatekeeper Hardware

Install the routers that will serve as session border controllers in your VoIP network.

Cisco Unified Border Element with Gatekeeper Software

Cisco Product Authorization Key (PAK)


Activation Before you can configure the software features described in this guide, you will need a Product Authorization Key (PAK). Before you start the configuration process, please register your products and activate your PAK at the following URL http://www.cisco.com/go/license.


Obtain the appropriate feature license for each router on which you will install an image that supports the Cisco Unified Border Element with Gatekeeper feature. Additional information on obtaining a feature license can be found at:

http://www.cisco.com/en/US/prod/collateral/voicesw/ps6790/gatecont/ps5640/product_data_sheet09186a00801da698.html

Install the appropriate Cisco IOS image on each router and configure a working VoIP network.

Use Cisco Feature Navigator to find information about platform support and software image support. Cisco Feature Navigator enables you to determine which Cisco IOS and Catalyst OS software images support a specific software release, feature set, or platform. To access Cisco Feature Navigator, go to http://tools.cisco.com/ITDIT/CFN/. An account on Cisco.com is not required.

Table 1 provides additional information on image and feature sets that support the Cisco Unified Border Element with Gatekeeper.

Table 1 Cisco IOS Image and Feature Sets for the Cisco Unified Border Element with Gatekeeper Feature 

Platform
Software Image Name
Software Feature Set

Cisco 2601XM
Cisco 2611XM
Cisco 2620XM
Cisco 2621XM
Cisco 2650XM
Cisco 2651XM

c2600-adventerprisek9_ivs-mz
c2600-ipvoice_ivs-mz

Cisco 2600 INT VOICE/VIDEO, IPIPGW, TDMIP GW AES
Cisco 2600 INT VOICE/VIDEO, IPIPGW, TDMIP GW

Cisco 2691

c2691-adventerprisek9_ivs-mz
c2691-ipvoice_ivs-mz

Cisco 2600 INT VOICE/VIDEO, IPIPGW, TDMIP GW AES
Cisco 2600 INT VOICE/VIDEO, IPIPGW, TDMIP GW

Cisco 2851
Cisco 2821
Cisco 2811

c2800nm-adventerprisek9_ivs-mz
c2800nm-ipvoice_ivs-mz

Cisco 2800 INT VOICE/VIDEO, IPIPGW, TDMIP GW AES
Cisco 2800 INT VOICE/VIDEO, IPIPGW, TDMIP GW

Cisco 2801

c2801-adventerprisek9_ivs-mz
c2801-ipvoice_ivs-mz

Cisco 2801 INT VOICE/VIDEO, IPIPGW, TDMIP GW AES
Cisco 2801 INT VOICE/VIDEO, IPIPGW, TDMIP GW

Cisco 3725

c3725-adventerprisek9_ivs-mz
c3725-ipvoice_ivs-mz

Cisco 3725 INT VOICE/VIDEO, IPIPGW, TDMIP GW AES
Cisco 3725 INT VOICE/VIDEO, IPIPGW, TDMIP GW

Cisco 3745

c3745-adventerprisek9_ivs-mz
c3745-ipvoice_ivs-mz

Cisco 3745 INT VOICE/VIDEO, IPIPGW, TDMIP GW AES
Cisco 3745 INT VOICE/VIDEO, IPIPGW, TDMIP GW

Cisco 3825

c3825-adventerprisek9_ivs-mz
c3825-ipvoice_ivs-mz

Cisco 3825 INT VOICE/VIDEO, IPIPGW, TDMIP GW AES
Cisco 3825 INT VOICE/VIDEO, IPIPGW, TDMIP GW

Cisco 3845

c3845-adventerprisek9_ivs-mz
c3845-ipvoice_ivs-mz

Cisco 3845 INT VOICE/VIDEO, IPIPGW, TDMIP GW AES
Cisco 3845 INT VOICE/VIDEO, IPIPGW, TDMIP GW

Cisco AS5350XM

c5350-adventerprisek9_ivs-mz
c5350-ipvoice_ivs-mz

Cisco 5350 INT VOICE/VIDEO, IPIPGW, TDMIP GW AES
Cisco 5350 INT VOICE/VIDEO, IPIPGW, TDMIP GW

Cisco AS5400XM

c5400-adventerprisek9_ivs-mz
c5400-ipvoice_ivs-mz

Cisco 5400 INT VOICE/VIDEO, IPIPGW, TDMIP GW AES
Cisco 5400 INT VOICE/VIDEO, IPIPGW, TDMIP GW

Cisco 7200

c7200-adventerprisek9_mz
c7200-adventerprisek9_li-mz
c7200-adventerprisek9_li-mz

Cisco 7200 Series IOS ADVANCED ENTERPRISE SERVICES

Cisco 7301

c7301-adventerprisek9_mz
c7301-adventerprisek9_li-mz
c7200-adventerprisek9_li-mz

Cisco 7301 Series IOS ADVANCED ENTERPRISE SERVICES


Restrictions for Cisco Unified Border Element with Gatekeeper Configuration

Via-zone-enabled gatekeepers are not supported by Cisco Unified Communications Manager.

Information About Cisco Unified Border Element with Gatekeeper

Feature benefits include the following:

Capacity control and improved call routing control using carrier-based routing with the Cisco Unified Border Element with Gatekeeper feature and routing traffic through the gateways.

Improved billing and settlement capabilities.

Provides key services at the edge of the network for scalability.

To configure the Cisco Unified Border Element with Gatekeeper feature, you should understand the following concepts:

Gatekeeper Functionality

Cisco Unified Border Element with Gatekeeper Network Topology

Features Supported by the Cisco Unified Border Element with Gatekeeper

Gatekeeper Functionality

Gatekeepers are responsible for the following tasks.

Gateway selection and load balancing

Call routing (zone selection)

Gatekeeper-based billing

Control of call admission, security, and bandwidth

Enforcement of call capacities

Cisco Unified Border Element with Gatekeeper Network Topology

In the current VoIP market, ITSPs who provide wholesale VoIP services use their own IP-to-TDM gateways to exchange calls with the PSTN. Problems occur when a wholesaler receives a call from an originating ITSP and decides to terminate the call to another ITSP. Because it does not own the PSTN gateways, the wholesaler does not receive call setup or release information and therefore cannot bill for the call. Wholesalers are forced either to forbid these connections, thereby foregoing a potential revenue source, or to set up the call through a combination of back-to-back IP-to-TDM gateways. This solution results in reduced quality due to double media coding and decoding, and it wastes TDM port resources.

Cisco UBE allows the wholesaler to terminate the call from the originating ITSP and then reoriginate it, thereby providing a point at which accurate call detail records (CDRs) can be collected for billing.

The superior interconnect capability provided by the Cisco UBE enables service providers to conceal their internal network and business relationships while improving call admission control, flexible routing, and protocol interworking capabilities.

The Cisco UBE includes the following changes to gateways and gatekeepers to allow Cisco UBE with Gatekeeper call legs:

Support for H.323-to-H.323, H.323-to-SIP, and SIP-to-SIP connection types

Support for transparent codec on H.323-to-H.323 connection types

Support for H.323 call capacities

Introduction of gatekeeper via-zones. Via-zone is a Cisco term for a zone that contains Cisco UBEs and via-zone-enabled gatekeepers. A via-zone-enabled gatekeeper is capable of recognizing via-zones and sending traffic to via-zone gateways. Cisco via-zone-enabled gatekeepers include a via-zone command-line interface (CLI) command.

Via-zones are usually located on the edge of an ITSP network and are like a VoIP transfer point, or tandem zone, where traffic passes through on the way to the remote zone destination. Gateways in this zone terminate requested calls and reoriginate traffic to its final destination. Via-zone gatekeepers operate as usual for applications that are not Cisco UBE Gatekeepers in via-zones support resource management (for example, gateway selection and load balancing) using the Capacities field in the H.323 Version 4 RAS messages.

Figure 1 shows a simple topology example of the Cisco UBE using via-zone gatekeepers.

Figure 1 Cisco Unified Border Element with Gatekeeper Feature Sample Topology

The gatekeeper in Domain A and the gatekeeper in Domain B are connected to the via-zone gatekeeper. GK408 and the via-zone gatekeeper exchange Registration, Admission, and Status (RAS) messages for the originating side. Then the connection is made between the originating gateway and the Cisco UBE. The via-zone gatekeeper exchanges RAS messages with GK919 for the terminating side. If the call is accepted, the Cisco UBE completes the connection from GW408 to GW919, and the media flows through the Cisco UBE.

In a basic call scenario, on receiving a location request (LRQ) message from the originating gatekeeper (GK408), the via-zone-enabled gatekeeper (GKVIA) processes the message and determines that the call should be set up using the Cisco UBE. After the originating gateway receives its admission confirmation (ACF) message, it sets up the call.

With the Cisco Multiservice IP-to-IP Gateway feature, instead of the originating gateway signaling the terminating gateway directly, the Cisco UBE controls the call set-up both the signaling and media channel. The Cisco UBE is terminating the signaling and media channels, but the information associated with the media is propagated through to the opposite call leg. This process allows the endpoints to determine what media channel capabilities to use for the call. When the call is established, the audio stream flows through the Cisco UBE, meaning that the gateway terminates the audio channel on one call leg and then reoriginates it to the other leg.

The following scenario illustrates a basic call from the originating gateway to the terminating gateway, using the Cisco UBE and gatekeepers.

1. GW408 (the originating gateway) calls someone in the 919 area code, which is serviced by GW919 (the terminating gateway).

2. GW408 sends an ARQ with the called number having the 919 area code to a gatekeeper in its zone (GK408).

3. GK408 resolves 919 to belong to a via-zone gatekeeper (GKVIA). GK408 then sends an LRQ to GKVIA.

4. GKVIA receives the LRQ for the 919 number. GKVIA resolves the 919 prefix to belong to the Cisco UBE. GKVIA is configured to route requests for 919 prefix calls through its Cisco UBE. GKVIA sends an LCF to GK408.

5. GK408 returns an ACF specifying Cisco UBE to GW408.

6. GW408 sends a SETUP message to Cisco UBE for the 919 number.

7. Cisco UBE consults GKVIA with an ARQ message with the answerCall=true parameter to admit the incoming call.

8. GKVIA responds with an ACF to admit the call. From the perspective of the gatekeeper, the first call leg has been established.

9. Cisco UBE has a dial peer specifying that RAS messages should be sent to GKVIA for all prefixes. Cisco UBE initiates the resending of the call by sending the ARQ message with the answerCall parameter set to, false to GKVIA for 919.

10. GKVIA knows that prefix 919 belongs to GK919, and since the source zone is the via-zone, the GKVIA sends an LRQ to GK919.

11. GK919 sees prefix 919 as a local zone and sends an LCF pointing to GW919.

12. GKVIA returns an ACF specifying GW919.

13. Cisco UBE sends a SETUP message to GW919 for the 919 call.

14. GW919 sends an ARQ to GK919 to request admission for the call.

15. GK919 sends an ACF with the answerCall=true parameter.

All other messages (for example, Proceeding, Alerting, and Connect) are created as two legs between GW408, and GW919, with the Cisco UBE acting as an intermediate gateway

Features Supported by the Cisco Unified Border Element with Gatekeeper

This section contains lists of the following types of supported features:

Gatekeeper Call-Signaling Features

Gatekeeper-Related Features

Interoperability Features

Gatekeeper Call-Signaling Features

Table 2 is a list of supported Gatekeeper call-signaling features.

Table 2 Cisco Unified Border Element with Gatekeeper Call Signaling Features

Feature
H.323-to-H.323 Support?
H.323-to-SIP Support?
SIP-to-SIP Support?
Additional Information

Alternate endpoint retry

Yes

Configuration for all alternate endpoints must be consistent.GK

Alternate gatekeeper support

Yes

Annex E

Yes

Bandwidth request (BRQ)

Yes

Call Deflection (H.450.3)

No

Call multiplexing over single H.225 channel

Yes

Carrier-based routing

Yes

Facility Call Forward

No

Facility RouteCall to Gatekeeper

Yes

Gatekeeper security

Yes

Interdomain LRQ authentication

Yes

Interzone token

Yes

IRR call start time

Yes

IRR frequency

Yes

ISUP/GTD transport in H.225
(Annex M.2)

Yes

Lightweight RRQs

Yes

Overlap signaling processing on H.323 terminating gateways

Yes

QSIG Tunneling

Yes

Security checks at GK for ARQ/DRQ/ BRQ/URQ/IIR

Yes

Introduced in Cisco IOS Release12.4(15)XY.

Security Checks at GK for RRQ

Yes

Introduced in Cisco IOS Release12.4(15)XY.

Source CallSignaling address (in the answer ARQ)

Yes

Unsolicited IRR with billing token

Yes


Gatekeeper-Related Features

Table 3 shows a list of supported gatekeeper-related features. Those gatekeeper functions not listed are supported in conjunction with via-zones.

Table 3 Supported Gatekeeper-Related Features 

Feature
Supported?

Directory gatekeepers

Yes

Gatekeeper clusters

Yes

Annex G border elements

No

ISUP/GTD transport in RAS

Yes

GKTMP

Yes

Multiple local zones

Yes

Hot Standby Router Protocol (HSRP)

Yes


Interoperability Features

Table 4 shows a list of supported interoperability features.

Table 4 Supported Interoperability Features

Feature
Supported?
Additional Information

BroadSoft

Yes

First supported in 12.4(6)T images.

Cisco ATA 186

Yes

Cisco ATA 188

Yes

First supported in 12.3(7)T images.

Cisco Unified Communications Manager

Yes

Cisco CallManager Express

Yes

Cisco gateways

Yes

Compatible with H.323 version 2 and above.

Cisco MCM Proxy

Yes

Cannot register proxy in the same zone as an Cisco UBE.

Third-party gatekeepers

Yes

Third-party gatekeepers must support the equivalent of via-zone functionality.

Third-party gateways

Partially

First supported in 12.3(7)T images.


Additional References

The following sections provide additional references related to the Cisco Unified Border Element with Gatekeeper.


NoteIn addition to the references listed below, each chapter provides additional references related to Cisco Unified Border Element.

Some of the products and services mentioned in this guide may have reached end of life, end of sale, or both. Details are available at http://www.cisco.com/en/US/products/prod_end_of_life.html.

The preface and glossary for the entire voice-configuration library suite of documents is listed below.


Related Documents

Related Topic
Document Title

Cisco IOS commands

Cisco IOS Master Commands List, All Releases

Cisco IOS Voice commands

Cisco IOS Voice Command Reference

Cisco IOS Voice Configuration Library

For more information about Cisco IOS voice features, including feature documents, and troubleshooting information—at

http://www.cisco.com/en/US/docs/ios/12_3/vvf_c/
cisco_ios_voice_configuration_library_glossary/vcl.htm

Cisco IOS Release 15.0

Cisco IOS Release 15.0 Configuration Guides

Cisco IOS Release 12.4

Cisco IOS Release 12.4 Configuration Guides

Cisco IOS Release 12.4T Configuration Guides

Cisco IOS Release 12.3

Cisco IOS Release 12.3 documentation

Cisco IOS Voice commands

Cisco IOS Voice Troubleshooting and Monitoring Guide

Tcl IVR Version 2.0 Programming Guide

Cisco IOS Release 12.2

Cisco IOS Voice, Video, and Fax Configuration Guide, Release 12.2

DSP documentation

High-Density Packet Voice Feature Card for Cisco AS5350XM and AS5400XM Universal Gateways

http://www.cisco.com/en/US/docs/ios/12_4t/12_4t11/vfc_dsp.html

GKTMP (GK API) Documents

GKTMP Command Reference: http://www.cisco.com/en/US/docs/ios/12_2/gktmp/gktmpv4_2
/
gk_cli.htm

GKTMP Messages: http://www.cisco.com/en/US/docs/ios/12_2/gktmp/gktmpv4_2/gk_tmp.html

internet Low Bitrate Codec (iLBC) Documents

Codecs section of the Dial Peer Configuration on Voice Gateway Routers Guide

http://www.cisco.com/en/US/docs/ios/12_3/vvf_c/dial_peer/
dp_ovrvw.html

Dial Peer Features and Configuration section of the Dial Peer Configuration on Voice Gateway Routers Guide

http://www.cisco.com/en/US/docs/ios/12_3/vvf_c/dial_peer/
dp_confg.html

Cisco Unified Border Element Configuration Examples

Local-to-remote network using the IPIPGW
http://www.cisco.com/en/US/tech/tk1077/technologies_configuration_
example09186a00801b0803.shtml

Remote-to-local network using the IPIPGW: http://www.cisco.com/en/US/tech/tk1077/
technologies_configuration_example09186a0080203edc.shtml

Remote-to-remote network using the IPIPGW: http://www.cisco.com/en/US/tech/tk1077/
technologies_configuration_example09186a0080203edd.shtml

Remote-to-remote network using two IPIPGWs: http://www.cisco.com/en/US/tech/tk1077/
technologies_configuration_example09186a0080203edb.shtml

Related Application Guides

Cisco Unified Communications Manager and Cisco IOS Interoperability Guide

Cisco IOS Fax, Modem, and Text Support over IP Configuration Guide

"Configuring T.38 Fax Relay" chapter

Cisco IOS SIP Configuration Guide

Cisco Unified Communications Manager (CallManager) Programming Guides

Quality of Service for Voice over IP

Related Platform Documents

Cisco 2600 Series Multiservice Platforms

Cisco 2800 Series Integrated Services Routers

Cisco 3600 Series Multiservice Platforms

Cisco 3700 Series Multiservice Access Routers

Cisco 3800 Series Integrated Services Routers

Cisco 7200 Series Routers

Cisco 7301

Related gateway configuration documentation

Media and Signaling Authentication and Encryption Feature for Cisco IOS H.323 Gateways.

http://www.cisco.com/en/US/docs/ios/12_4t/12_4t11/htsecure.htm

Cisco IOS NAT Configuration Guide, Release 12.4T

Configuring Cisco IOS Hosted NAT Traversal for Session Border Controller

http://www.cisco.com/en/US/docs/ios/12_4t/ip_addr/configuration/guide/htnatsbc.html

Troubleshooting and Debugging guides

Cisco IOS Debug Command Reference, Release 12.4 at

http://www.cisco.com/en/US/docs/ios/debug/command/reference/db_book.html

Troubleshooting and Debugging VoIP Call Basics at http://www.cisco.com/en/US/tech/tk1077/technologies_tech_note09186a0080094045.shtml

VoIP Debug Commands at

http://www.cisco.com/en/US/docs/routers/access/1700/1750/software/configuration/guide/debug.html


Standards

Standard
Title

H.323 Version 4 and earlier

H.323 (ITU-T VOIP protocols)


MIBs

MIB
MIBs Link

None.

To locate and download MIBs for selected platforms, Cisco IOS releases, and feature sets, use Cisco MIB Locator found at the following URL:

http://www.cisco.com/go/mibs


RFCs

RFC
Title

RFC 2833

RTP Payload for DTMF Digits, Telephony Tones and Telephony Signals

RFC 3261

SIP: Session Initiation Protocol


Technical Assistance

Description
Link

The Cisco Support website provides extensive online resources, including documentation and tools for troubleshooting and resolving technical issues with Cisco products and technologies.

To receive security and technical information about your products, you can subscribe to various services, such as the Product Alert Tool (accessed from Field Notices), the Cisco Technical Services Newsletter, and Really Simple Syndication (RSS) Feeds.

Access to most tools on the Cisco Support website requires a Cisco.com user ID and password.

http://www.cisco.com/cisco/web/support/index.html


Glossay

IZCT—Inter-Zone Clear Token.

OGK —Originating Gatekeepe.r

TGK —Terminating Gatekeeper.

OGW—Originating Gateway.

TGW—Terminating Gateway.

ARQ— Admission Request.

ACF—Admission Confirm.

ARJ—Admission Reject.

LRQ—Location Request.

LCF— Location Confirm.

LRJ—Location Reject.