IMS: It means something but what?

One thing last month's Global Multiservice Interoperability event proved is that everyone has an opinion on where IP multimedia subsystem is going and how to get there. But those opinions, unlike the services IMS intends to support, are hardly converging.

For Verizon, a prime GMI advocate and one of three service providers hosting interoperability testing (the others being BT/Vodafone in the U.K. and China Mobile), helping to advance interoperability and identifying where standards are needed remain the best approach to IMS.

“The testing, even things that did not perform perfectly, has been an overall success, in that the things that worked well proved in valid approaches, and the things that did not work perfectly pointed out the areas that need attention,” said Naseem Khan, principal member of the technical staff for Verizon and a member of the board of the MultiService Forum. “We'll all be working to get the kinks out of the challenged test areas now that we know exactly what needs our attention.”

Some of the 22 participating vendors see IMS coming into the market now, with less interoperability and on a much smaller scale but in practical ways.

“In Europe, we see a number of service providers moving ahead with deploying IMS on a smaller scale, rather than waiting for every detail to be worked out,” said Matthias Glanz, head of product management for next-gen voice and multimedia for Nokia Siemens Networks.

In the U.S., AT&T is deploying IMS faster than the GMI participants, said Seamus Hourihan, vice president of marketing and product management for Acme Packet.

“What's interesting to me is that Verizon, BT and China Mobile are somewhat lagging the rest of the world in terms of actual IMS deployment at some level,” Hourihan said. IMS is highly complex but can be made simpler for practical deployments, he said.