Plugfests plug along, intercarrier focus up next

Even as it broadens its charter, the NGN/IMS Forum announced it will continue its Plugfest series of interoperability tests this January, focusing on the real-world interoperability of key IP multimedia subsystem, session initiation protocol and Diameter interfaces.

Although service provider IMS deployments have been slow to take off, the forum’s Plugfest events have generally been considered successful, bringing together key vendors to test IMS interfaces and service scenarios in a live environment. Earlier this month, the IMS Forum merged with the NGN Forum, expanding its focus — including the focus of the Plugfests.

The next test will be held Jan. 12-16 at the usual location in the Interoperability Lab in Durham, N.H. Attending vendors include: Acision, Aricent, HP, Intel, Marben Products, Mu Daynamics, Sonus, Tekelec and Wipro.

Recent Plugfests have focused on user-to-service provider interface testing, billing/charging interfaces and more. For Plugfest 6, the focus will be on three key areas: internetwork testing, interoperability between SIP and Diameter interfaces, and ongoing examination and testing of the role of service delivery platforms in NGN environments, said Michael Khalilian, chairman and president of the NGN/IMS Forum, in an interview. Services to be tested include voice over IP for resident and enterprise users, unified communications, IPTV and fixed/mobile convergence.

“From here on out, we are branching off from looking at IMS only,” Khalilian said, with a nod toward his group’s recent merger with the NGN Forum. “At least partially, NGN has nothing to do with IMS. NGN represents the true convergence of the previous network with new IP networks and IP delivery. IMS is the ultimate [target] of that architecture.”

Along with expanding its charter to include NGN, the forum is creating new technical working groups to delve deeper into related protocols. For instance, the group has formed and will soon announce new working groups covering SIP and Diameter protocols, particularly in a multiservice environment, said Manual Vexler, chair of the NGN/IMS Forum technical working groups.

“We’ve gotten to the stage where we’ll be looking at a very granular level at the implementations differences at the protocol level,” Vexler said. One of the challenges of the IMS specifications, in particular, is that they define an approach to offering next-generation services rather than actual requirements. That means that the devil is in the implementation details — information that the forum and its new working groups aim to give back to NGN-focused standards bodies, Vexler said.