Email	Print Reprint
	add to:
	Del.icio.us Digg Google Furl	Slashdot Y! MyWeb Blink

Media Gateway Control Protocol

Low-cost residential gateways are a critical element of voice-over IP's drive to mass-market acceptance because they allow consumers to connect to a VoIP network. H.323- and SIP-based gateways must be upgraded each time a new feature or service is added to the network. Since software upgrades may intimidate consumers, the industry is searching for a protocol that balances media and call-control features to reduce the number of software upgrades.

The IETF's solution to this dilemma is the Media Gateway Control Protocol (MGCP). Like SIP, MGCP is a stateless, text-based protocol. Unlike SIP, MGCP concentrates only on endpoint-specific issues (such as tone detection and media stream setup) and relies on a companion protocol (SIP, H.323, and the like) to locate users, connect parties, and perform other signaling functions. MGCP's concentration on gateway-specific controls minimizes the need to upgrade consumer devices and simultaneously reduces the work effort required to implement a gateway.

The ITU has proposed its version of a simpler gateway protocol called "H.GCP," which breaks up the H.323 model into subcomponents and defines protocols over which the components interact. H.GCP does not specify how H.323 gateways, multipoint control units, or integrated voice response units work. Instead, it recommends a framework is suitable for such systems.

Before another H.323 versus SIP protocol war erupted between the ITU and IETF, the "MEGACO" protocol was drafted. It combines the best features of the IETF solution (MGCP) with the ITU solution (H.GCP), and currently is in draft status. The MGCP draft is available for review at http://search.ietf.org/internet-drafts/ draft-huitema-megaco-mgcp-v0r1-05.txt, the specification is available at http://search .ietf.org/internet-drafts/draft-ietf-megaco-protocol-00.txt, and the specification for MGCP cable boxes is available at http://www.packetcable.com. For more information regarding Megaco, see ftp:// standards.nortelnetworks.com/megaco/ docs/oslo99/. Information regarding the Megaco Working Group can be found at http://www.ietf.org/html.charters/ megaco-charter.html, and the Megaco archives are available at http://standards .nortelnetworks.com/archives/megaco.html.

-- L.D.

Previous Page | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 Next Page

RELATED ARTICLES Securing the Java Core Petascale Tools and Genomic Evolution Legal Compliance: Open Source and Quality Assurance SEI, Army Team Up on Software Testing Highly Scalable Parallel Sorting		TOP 5 ARTICLES No Top Articles.