Cisco IOS MGCP and Related Protocols Configuration Guide - Overview of MGCP and Related Protocols [Cisco IOS Software Releases 12.3 T]

Table Of Contents

Overview of MGCP and Related Protocols

Contents

Prerequisites for Configuring MGCP and Related Protocols

Information About MGCP and Related Protocols

Supported Gateways

Residential Gateway

Trunking Gateway

Additional References

Related Documents

MIBs

Technical Assistance

Overview of MGCP and Related Protocols

This chapter provides overview information on Media Gateway Control Protocol (MGCP) and related protocols.

Note For more information about Cisco IOS voice features, see the entire Cisco IOS Voice Configuration Library—including library preface and glossary, feature documents, and troubleshooting information—at http://www.cisco.com/en/US/products/ps6441/prod_configuration_guide09186a0080565f8a.html

Contents

•Prerequisites for Configuring MGCP and Related Protocols

•Information About MGCP and Related Protocols

•Additional References

Prerequisites for Configuring MGCP and Related Protocols

•Configure IP routing.

•Configure voice ports.

•Configure VoIP.

•Configure the call agent. (For information on setting up call agents, see the documentation that accompanies the call agents used in your network configuration.)

Information About MGCP and Related Protocols

MGCP is an extension of the earlier version of the protocol Simple Gateway Control Protocol (SGCP) and supports SGCP functionality in addition to several enhancements. Systems using SGCP can easily migrate to MGCP, and MGCP commands are available to enable SGCP capabilities.

An MGCP gateway handles translation between audio signals and the packet network. Gateways interact with a call agent (CA)—also called a media gateway controller (MGC)—that performs signal and call processing on gateway calls. In the MGCP configurations that Cisco IOS supports, a gateway can be a Cisco router, access server, or cable modem, and the CA is a server from a third-party vendor.

Configuration commands for MGCP define the path between the call agent and the gateway, the type of gateway, and the type of calls handled by the gateway.

MGCP uses endpoints and connections to construct a call. Endpoints are sources of or destinations for data, and can be physical or logical locations in a device. Connections can be point-to-point or multipoint.

Similar to SGCP, MGCP uses User Datagram Protocol (UDP) for establishing audio connections over IP networks. However, MGCP also uses hairpinning to return a call to the PSTN when the packet network is not available.

Package Types

A call connection involves a series of events and signals—such as off-hook status, a ringing signal, or a signal to play an announcement—that are specific to the type of endpoint involved in the call.

MGCP groups these events and signals into packages. A trunk package, for example, is a group of events and signals relevant to a trunking gateway; an announcement package is a group of events and signals relevant to an announcement server. MGCP supports the following seven package types:

•Trunk

•Line

•Dual-tone multifrequency (DTMF)

•Generic media

•Real-Time Transport Protocol (RTP)

•Announcement server

•Script

The trunk package and line package are supported by default on certain types of gateways. Although configuring a gateway with additional endpoint package information is optional, you may want to specify packages for your endpoints to add to or override the defaults.

Protocol Benefits

MGCP provides the following benefits:

•Alternative dial tone for VoIP environments—Deregulation in the telecommunications industry gives competitive local-exchange carriers (CLECs) opportunities to provide toll bypass from the incumbent local-exchange carriers (ILECs) by means of VoIP. MGCP enables a VoIP system to control call setup and teardown and Custom Local Area Subscriber Services (CLASS) features for less sophisticated gateways.

•Simplified configuration for static VoIP network dial peers—When you use MGCP as the call agent in a VoIP environment, you need not configure static VoIP network dial peers. The MGCP call agent provides functions similar to VoIP-network dial peers.

Note Plain old telephone service (POTS) dial peer configuration is still required.

•Migration paths—Systems using earlier versions of the protocol can migrate easily to MGCP.

•Varied network needs supported for the following:

–Interexchange carriers (IXCs) who have no legacy time-division multiplexing (TDM) equipment in their networks and want to deploy a fully featured network that offers both long-distance services to corporate customers and connectivity to local exchange carriers or other IXCs with traditional TDM equipment.

–IXCs who have TDM equipment in their networks and want to relieve network congestion using data technologies to carry voice traffic or to cap the growth of TDM ports. In these situations, the packet network provides basic switched trunking without services or features.

–Competitive competitive local-exchange carriers (CLECs) who want to provide residential and enhanced services.

–Dial-access customers who want enhanced Signaling System 7 (SS7) access capabilities and increased performance, reliability, scalability, and economy.

Supported Gateways

MGCP supports both residential and trunking gateways.

Residential Gateway

A residential gateway (RGW) provides an interface between analog (RJ-11) calls from a telephone and the VoIP network. Examples of RGWs include cable modems and Cisco 2600 series routers. Figure 1 shows an RGW configuration.

Figure 1 Residential and Trunking Gateways

RGW functionality supports analog POTS calls for both SGCP and MGCP on the Cisco 2600 series routers and Cisco uBR924 cable access router as shown in Table 1.

Table 1 RGW Functionality

Functionality

Platform

Cisco 2600 Series

Cisco uBR924

Call waiting

Yes

Yes

Default call-agent address specifiable for each foreign exchange station (FXS) port

—

Yes

Distinctive ringing

—

Yes

Fax and modem calls

Yes

Yes

On-hook caller identification (ID)

—

Yes

Ring splash

—

Yes

Stutter dial tone

Yes

Yes

Trunking Gateway

A trunking gateway (TGW) provides an interface between PSTN trunks and a VoIP network. A trunk can be a DS0, T1, or E1 line. Examples of TGWs include access servers and routers. Figure 2 shows a TGW configuration.

Figure 2 Trunking Gateways

TGW functionality supports SGCP and MGCP as shown in Table 2.

Table 2 TGW Functionality

Functionality

Platform

Cisco AS5300

Cisco 3660

911 outgoing calls on T1 lines

Yes¹

Fax and modem calls

Yes

Yes

PRI/ISDN signaling (calls are backhauled to the call agent)

Yes

SS7

Yes

Yes

T1 and E1 interfaces

Yes

Yes

¹Server must have SGCP 1.1+ protocol for Feature Group D Operator Services (FGD-OS)

Additional References

The following sections provide references related to <<technology area>>.

Related Documents

Related Topic

Document Title

Cisco IOS configuration examples

Cisco Systems Technologies website at http://cisco.com/en/US/tech/index.html. Select a technology category and subsequent hierarchy of subcategories. Click Technical Documentation > Configuration Examples.

Cisco IOS debug command reference

Cisco IOS Debug Command Reference, Release 12.3T at http://www.cisco.com/univercd/cc/td/doc/product/software/ios123/123tcr/123dbr/index.htm

Cisco IOS troubleshooting information

Cisco IOS Voice Troubleshooting and Monitoring Guide at http://www.cisco.com/univercd/cc/td/doc/product/software/ios123/123cgcr/vvfax_c/voipt_c/index.htm

Cisco IOS voice command reference

Cisco IOS Voice Command Reference, Release 12.3T at http://www.cisco.com/univercd/cc/td/doc/product/software/ios123/123tcr/123tvr/index.htm

Cisco IOS Voice Configuration Library preface and glossary

Cisco IOS Voice Configuration Library at http://www.cisco.com/en/US/products/ps6441/prod_configuration_guide09186a0080565f8a.html

MIBs

MIBs

MIBs Link

•

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

Technical Assistance

Description

Link

Technical Assistance Center (TAC) home page, containing 30,000 pages of searchable technical content, including links to products, technologies, solutions, technical tips, and tools. Registered Cisco.com users can log in from this page to access even more content.

http://www.cisco.com/public/support/tac/home.shtml