Today, we return to our series on IP Multimedia Subsystem (IMS) progress with excerpts from an interview we had with Randy Waters, vice president of market development at Comverse, a leading provider of software and systems enabling network-based messaging and content value-added services, converged billing and IP communications. Waters believes one of the impediments to successful IMS deployments is that to provide end-to-end IMS compliant services, service providers must allow for "hundreds of [customer premises equipment] devices that are changing over time with every new release" but he noted that CPE manufacturers are making progress, so the associated CPE challenges are "getting better."

By contrast, Waters said that with core network device interoperability (counting components like Signaling System 7 - SS7 - gateways, softswitches, and session border controllers) “interoperability is more straightforward, [despite] the complexity of these elements.”

When asked about proven interoperability of IMS in a multivendor environment, Waters said that in Europe, Comverse was already working in live multivendor networks to provide both residential and business voice services and that when it came to unified communications features like visual voicemail, he expects to see demonstrable multivendor interoperability in the next few months.

Specifically, he said that “the applications we have tested using our [Telephony Application Server] on several IMS core network components are residential VoIP, IP Centrex, and push-to-talk over cellular. We have also tested instant messaging, presence, SMS and [Multimedia Messaging Services] from our associated messaging application servers on IMS core components. The messaging applications have been tested less extensively than the voice applications.”

As for IPTV running on IMS, Waters doesn’t “see the IPTV world worrying so much about IMS, although [Comverse has] integrated some telephony features into IPTV middleware.”

Finally, we asked him when he thinks IMS will replace SS7, and he concluded that “as long as there is a circuit-switched PSTN, there will be an SS7, but as applications on the PSTN become more intelligent IMS will continue to evolve although [the evolution] will take time.”

Next time, we hear from AT&T about its progress with deploying IMS.