NGN/IMS Forum report: IMS coming, just not as expected

At the risk of being accused of protesting too much, the NGN/IMS Forum nonetheless saw the need this week to release the IMS NGN Forum report card, a document that it says addresses the confusion and “myths” regarding the deployment of IP Multimedia Subsystem technology.

If the report has a bottom line, it’s this: IMS has been thoroughly tested and is being deployed, just not as quickly or in as complete a fashion as many – including the forum itself, not to mention its vendor members – and originally hoped or anticipated.

Proof that IMS isn’t all that was hoped or expected comes from the IMS Forum itself, which just last month merged with the NGN Forum, a nod to the fact that network architectures for delivering next-generation services -- while certainly guided by IMS principles – aren’t strictly beholden to them.

“NGN tends to be the broader term, overlapping with IMS,” said Manuel Vexler, Chair of IMS Technical Working Groups. “When you look at NGN, you typically see an evolution to an IP network with management and quality of service. Sometimes it’s a partial service [rather than a truly convergent service] and it doesn’t always and necessarily imply an IMS architecture. What IMS and NGN share is that they are managed IP networks with the same building blocks: quality of service, policy enforcement, billing, management and security.”

It’s hard to argue that those elements will be at the center of future service provider networks. The Report Card takes things a step further, attempting to refute specific misconceptions about IMS in a variety of categories, including: Business Case, Complexity, IMS Core, Standards, Interoperability, Key Features SIP Integration, Applications, Deployment and Legacy Network. The report card bases its case mainly on the results from the five IMS Forum plugfests conducted to date, Vexler said.

Overall, Vexler said, NGN deployment is happening on an element-by-element basis. In turn, IMS services are being deployed on a service-by-service basis. Pure, greenfield IMS deployments don’t exist because such environments rarely exist in the real world, he said. The key to this approach is that it sets the stage for fuller, converged IMS networks down the line, he added.

The report card states the same idea in this way: “It remains an open question whether we will ever see a proliferation of ‘all-IMS networks’ – the complete architecture as described by the various standards bodies. But we will most certainly see networks built using those elements of IMS that are fundamental to building IP-enabled infrastructures.”