Network architectures spur need for new protocols

A group of new forums is scrambling to hone the development of standards that are needed to bring about converged voice/data carrier networks.

The groups are trying to sort out competing technologies and protocols and come up with accepted technologies that will lead to interoperability among equipment made by different vendors.

Some of these forums are blatantly partisan, such as the Session Initiation Protocol (SIP) Forum, which is pushing SIP over H.323 as the protocol to negotiate voice and video sessions between voice and packet networks.

Others, such as the Open Voice Over Broadband (VoB) Forum, have a tangle of possibilities to sort through, and have stated their technology biases as a way to give their work direction. For instance, the group has chosen ATM over IP as the preferred transport method to link DSL customers’ voice and data traffic to carrier networks. It has selected IP, though, as the transport for cable access networks.

Within these parameters, Open VoB also has to sort through a list of signaling protocols that will translate call signals between transport protocols, such as ATM and time-division multiplexing, being used in different segments of carrier nets.

While none of Open VoB’s founders is a service provider, some forums seek carrier participation to determine the specifications of the gear carriers want to buy. For instance, the Multiservice Switching Forum (MSF) includes representatives of Qwest Communications International Inc., WorldCom Inc., British Telecommunications PLC and Telecom Italia SA on its board of directors.

“Carriers decide what they will buy and vendors decide what to sell. If we can build what they say they will buy, we will have success,” says Avri Doria, chief architect of Nortel Networks Corp.’s routing architecture, who is also on the MSF board of directors.

MSF’s goal is to push for standards that will let equipment makers build carrier switches that handle voice and data and can act as a bridge between traditional voice and data networks and developing IP nets.

The group is anchored by heavyweights in carrier gear manufacturing whose influence will likely sway the direction the industry takes. Cisco Systems Inc., Lucent Technologies Inc., Nortel and Siemens AG are also all represented on the MSF board. They can give direction to the formal standards bodies – such as the Internet Engineering Task Force (IETF) and International Telecommunication Union (ITU) – to approve standards that address the practical demands of carrier networks.

Agreement on standards and interoperability between vendor gear is important to many carriers because they prefer to buy from more than one equipment maker to get better prices and to ensure a steady supply of products.

Less influential vendors than Cisco and Nortel that are involved in these new ad hoc forums may be driven by self-interest as well, but at the same time they are the ones most familiar with the strengths of the new technologies they develop, says Woody Benson, president and CEO of MCK Communications Inc., which makes gear to extend corporate phone networks.

“New technologies are coming from new vendors. They’re starting from scratch. The IETF and ITU don’t have the same focus. They have lots of legacy technology and lots of subgroups,” says Benson, a director of the National Convergence Alliance, a group set up to push combined voice and data networks.