IP multimedia system (IMS) network architecture has been around for a long time. While it was originally conceived for mobile IP networks, it first gained acceptance in wireline IP networks, such as cable networks. To date, acceptance has been spotty in the mobile arena, but that’s starting to change. Why now? I’ve seen various factors come together in order to enable IMS deployments. In a nutshell, I would say that common sense and practicality have reigned supreme. Imagine that!
One obvious factor is the emergence of LTE networks. In fact, more than 300 LTE networks have been deployed worldwide so far, with hundreds more planned. LTE networks are essentially IP networks, so it makes sense that IMS would be the network architecture best suited to roll out an LTE network.
However, there is another very important factor that is often overlooked. Many IMS deployments are occurring because the next-gen network (NGN) architectures that were deployed in the early 2000s are now in need of an upgrade. Yes, the NGN is no longer next-gen. The equipment is getting old and needs to interoperate with newer networks to survive. At Dialogic, we’ve seen instances of NGN softswitches that are now out of service being replaced with newer C4 switches that have IMS capabilities because the communications service provider (CSP) wants to bridge the existing network with newer IMS networks. You can think of this as some kind of hybrid IMS deployment.
We have also seen older media servers in the form of board-level solutions that are now being replaced with software-based media resource functions (MRFs). The application might still be a network voicemail (which could now include network video mail), but the media server architecture supporting the application can be more of an IMS architecture, in which the app server and media server are remote from each other. These MRFs can operate in full IMS architectures as well as NGN architectures.
In other words, CSPs are indeed going ahead and strategically replacing their circuit-switched equipment with packet-switched technology (including softswitches, media servers and session border controllers) in an effort to reduce costs and converge voice, data and video communications into richer multimedia sessions using the session initiation protocol (SIP) standard. And the packet-switching architecture of choice is IMS. To learn more about how CSPs can streamline the journey to IMS, check out Dialogic’s latest white paper.
