Unfortunately, many of the key components of the IP multimedia subsystem architecture—including the new mobile softswitches based on Advanced Telecom Computing Architecture standards—are still in the development phase.

That’s leading some operators not to count on future promises of interoperability and take the issue head on today. Verizon Business—formerly MCI—has not yet announced an IMS deployment, but it has executed a precise plan for IMS implementation that dictates all elements across the control, network and applications planes, said David Croslin, Verizon Business’ IT chief product architect. Croslin said Verizon has evaluated 37 different vendors for 26 possible components, specifically identifying each element it wants on its network. In the next quarter, it plans to send out a detailed request for proposal (RFP) for a vendor or group of vendors to draw those elements together, Croslin said.

“We don’t want to throw a rope around a bunch of silos and call it convergence,” Croslin said. “We’re ready to turn-up IMS. We just have to get our RFP out.”