Cable telephony dtente

In a rare display of cooperation, standards bodies throughout the world have joined to smooth the kinks of interoperable IP cable telephony.

Technical bodies — including CableLabs, the Society of Cable Telecommunications Engineers, the European Telecommunications Standards Institute and the International Telecommunication Union-Telecommunications Standardization Sector — have developed the IPCablecom standard.

While designed to address IP-voice-over-cable networks, IPCablecom also includes interfaces to international public switched telephone networks.

“It's significant because it builds on pre-existing technology and standards developed in the ITU… work done in [Internet Engineering Task Force] and other organizations,” said Richard Green, CableLabs president and CEO who also chairs ITU-T's Study Group 9. “This group has achieved the first international standard that we know of that allows for transmission of IP packets through the worldwide cable network.”

Foreign telcos struggling to keep competitive IP services at abeyance won't welcome the standardization effort.

Karl Heinz Rosenbrock, ETSI director general, said international operators would defend their territories, but ETSI supports using cable for voice transport.

“Internet protocols have the capability to transport the information for new and existing services without the need for traditional switching and transmission equipment,” he said. “This will make the new networks more cost-competitive as well as more resilient.”

Incumbent opposition is “only natural,” Rosenbrock said. “The one bird that is considered by some as an owl might be considered by others as a nightingale, as we say in German.”

International telcos wield less influence over their cable brethren's activities with two-way hybrid fiber/coax networks, said Kinetic Strategies President Michael Harris, who dubbed the conference “international technology détente.”

“Those telcos could still lobby very aggressively to make cable operators meet certain technology, performance, reliability requirements and delay their time to market… but they can't say anything about how [cable operators] run their competitive service,” Harris said.

IPCablecom extends the Euro DOCSIS cable-modem specification that grew from CableLabs' DOCSIS data specifications efforts. PacketCable — the IP telephony portion — is intrinsically wound into DOCSIS 1.1 and will be the foundation for IPCablecom, Green said.

“The goal is to have a worldwide standard,” he said. “We have efforts in CableLabs in PacketCable which are working on enhancements and, therefore, some elements of this are uniquely PacketCable, but I think we're in the process of coordinating that and beginning the internationalization of that effort.”

Eight of the 12 IPCablecom specifications have been approved as world standards, with the other four to be considered at ITU's next meeting, Green said. In the U.S., all 12 specifications have passed through SCTE and are being submitted to the American National Standards Institute for review and approval.

“Two to three months from now they will be formally approved as American national standards,” said Stephen Oksala, SCTE's vice president of standards. “History tells us that manufacturers who get the SCTE or the ITU standard at this point can build in North America with complete confidence that what they have as a specification is what will be there when all the little lines are signed.”

Europe is only “slightly behind,” said Jim Price, ETSI Operational Coordination Group on IP Cable Communications chairman and Telewest's head of standards engineering. “Manufacturers are working on the European variants as we speak, and we can expect to see product very quickly after the specifications have been ratified.”

All agreed that the end goal is interoperable IP telephony that knows no technological or state borders.

IPCablecom “provides an economic pathway to build hardware,” Green said. “It removes the uncertainty about which interfaces to construct. It encourages cable operators to move forward with the introduction of new services as it removes uncertainties about the actual technical provision of those services.”