Service providers investing in IP Multimedia Subsystem (IMS) equipment so far have been mixing and matching network elements from various vendors in pursuing their IMS-compliant architectures, a point that has been noted by several industry analysts. However, inCode Wireless, in its latest IMS Global Deployments Matrix, states that while providers can save costs on a component basis, they may sacrifice the interoperability encouraged by the IMS standard.

“This ‘mix-and-match’ approach will drive down operator costs in the long term,” said P.K. Prasanna, inCode IMS Technology Lead, in a statement announcing the most recent update on inCode's matrix (dated Jan. 30). “However, it may result in an ironic consequence. Particularly in early implementations, operators will find that they must allocate time and resources for integrating multiple vendor technologies—a challenging task that IMS was intended to eliminate.”

The drive for competitive differentiation among IMS equipment vendors is profound, in part because the IP landscape still is early on in its market development, and the market leaders remain unclear, but also because IMS equipment will replace existing infrastructure at lower cost.

To overcome interoperability problems, Prasanna said vendors are sponsoring “user forums” that serve as interoperability coalitions and marketing efforts. “This resembles the early days of frame relay and ATM, when a number of industry forums were established to accelerate adoption of these new technologies. However, if such forums are to succeed, one or more operators—especially across network domains, such as wireless and cable TV—must set the interoperability and service objectives.”

Prasanna added that it could be 2-4 years before plug-and-play IMS architectures become a reality.