Cable telephony standards go worldwide

International telecommunications standards bodies have joined forces to promote a set of interoperable IP telephony specifications for cable’s broadband networks.

Called IPCablecom, the specification “has been developed by way of a cooperative technical effort by the cable operators and vendors working through the standards bodies,” said Richard Green, president and CEO of CableLabs and chairman of the International Telecommunications Union-Telecommunications Standards Sector (ITU-T) Study Group 9.

Among the standards bodies helping formulate the specification are the Society of Cable Telecommunications Engineers (SCTE) in the U.S. and the European Telecommunications Standards Institute (ETSI). Their goal is a universal, interoperable IP telephony standard that bridges national and technical borders and is based primarily on CableLabs' DOCSIS data specifications, including its PacketCable IP telephony initiative.

IPCablecom “provides a core specification which can be adapted for the interfaces that need to be addressed in different regions throughout the world, including the interface to the public-switched network,” said Green.

That interface is particularly important as cable operators internationally bridge their networks onto incumbent telcos. Also important is the ability to overcome national regulatory barriers.

“We’re trying to incorporate as many of these (regulatory environments) as possible with an umbrella specification to avoid any national differences within Europe,” said Jim Price, chairman of ETSI’s Operational Coordination Group on IP Cable Communications and head of standards for Telewest. “Hopefully that can be achieved without causing manufacturers too much grief in terms of different equipment practices and different performance for different countries.”

Eight of IPCablecom’s 12 specifications have already been adopted as world standards. The remaining four are in various stages of approval with different standards bodies, with final ratification expected within the next few months.

“The goal here is to develop an ITU specification that would apply worldwide,” emphasized Green. “The ITU specification is more important to manufacturers than any regional specification. Clearly what we’re trying to do is be a component and help in every way we can to get an international standard.”