Speaking of: <g> linking up internet, telephone networks
November 27, 1998
Inter@ctive Week: An industry standard designed to let
voice-over-Internet Protocol networks
communicate with the regular phone network
is gaining support.
Last week, Bell Communications Research
Inc. joined with a technical advisory
committee headed by Level 3
Communications Inc. to consolidate their
disparate technologies and present a unified
group of specifications, called the Media
Gateway Control Protocol (MGCP), to the
standards-setting Internet Engineering Task
Force for review. A completed standard is
expected to be ratified in early 1999.
The standard could drive down networking
equipment prices and spur the voice-
over-Internet Protocol market by making
packet-based networks more scalable and
flexible.
MGCP is a hybrid of Level 3's packet-based
Internet Protocol Device Control (IPDC) spec
and Bellcore's (www.bellcore.com)
circuit-based Simple Gateway Control
Protocol. Both de facto standards address
similar functions, including the way network
connections are controlled, devices are
managed and networks are secured.
MGCP works with other network standards
and technologies, such as the SS7 network
that controls circuit- switched
communications and the H.323 standard for
sending voice and video over IP networks.
Some experts suggested the H.323 protocol
could be extended to support MGCP-like
functions. "But that would be reinventing
something that we've worked on very hard
for a long time," said Isaac Elliot, senior
director of voice network engineering at
Level 3 (www.l3.com) and chairman of the
technical committee that developed IPDC.
Under the new proposal, call-management
software, known as media gateway
controllers, can be set up at various points
along circuit-switched and packet- switched
networks to allow for a transparent
communication exchange between the two
net- works. The media controller software
resides separately from media gateway
devices, such as voice-over IP gateways,
voice-over-Asynchronous Transfer Mode
devices, cable modems, private branch
exchanges and circuit switches.
MGCP's separation of call control software
from multimedia devices lets service
providers construct more flexible and scalable
networks. For example, a service provider
could sell mixed-media services off several
media gateways -- in various parts of its
network -- while storing and managing user
information centrally in the network.
"You can deploy gateways, like voice-over-IP
devices, all over the world and only have to
deal with dozens rather than hundreds of
media controllers, " Elliot said.
A Network Connection
The Media Gateway Control Protocol is
designed to standardize the way phone
networks talk to Internet Protocol networks.
It is based on a combination of existing Bell
Communications Research Inc. and Level 3
Communications Inc. specifications.
Bellcore's Simple Gateway Control Protocol: A
simple language for call and connection
control between network end points and
media gateways, such as voice-
over-Internet Protocol gateways.
Level 3 Communications' Internet Protocol
Device Control (IPDC): A specification that
creates flexible management of media
gateway devices. The Media Gateway
Control Protocol removes the signaling
transport portion of IPDC to cut down on the
combined standard's overhead.
[Copyright 1998, Ziff Wire] |
