Tom Nolle, founder and president of CIMI Corporation and a longtime industry analyst recently published an "Unconventional Wisdom" brief titled "Beyond IMS" that we'd like to highlight today and also recommend to our readers. Nolle starts with the premise that, "One of the most significant technology shifts that have accompanied 'convergence' is the shift from conceptualizing service features as attributes of network devices to conceptualizing them as something hosted 'above' the network. Feature hosting is an integral part of the whole convergence concept, in fact." However, he points out that the shift also raises several questions and issues.

For example, Nolle asks: what do you host them on? How does feature hosting create a service experience as reliable as the PSTN? Can the stability offered by the past’s “telephone switch software ‘generics’ ever be replicated in the seemingly disorder space of application development?” He suggests, “It would be nice to say that there was an explosion of innovation created to provide those answers. Nice, but not true.”

Nolle observes that the PSTN conceptual model called the “Advanced Intelligent Network” (AIN) defined functional components like a Service Switching System, a Service Control Point, and an Intelligent Peripheral. However, the AIN was not defined to support a converged architecture “so convergence players apparently had a problem getting a handle on how the whole thing was supposed to come together. One can almost imagine all those vendors, desperate for guidance, floundering about in their labs. Then, when all was dark, came IMS.”

In his inimitable style, Nolle suggests that “the IP Multimedia Subsystem is perhaps the closest thing to transcendentalism that exists in networking. We can easily say that it contributes heavily to planning and zero to revenue (and at best next-to-zero in real investment).” But, Nolle concludes that IMS does have its merits, saying that IMS creates a framework for people to visualize feature-creating applications. Nolle says “From IMS roots came the central element in feature hosting today, the concept of the service delivery platform or SDP.” He continues, “There is no question that IMS promotes the notion of SDPs with its notion of signaling-driven feature applications.” But, he adds, “linking the concept of SDPs to IMS is like linking the delivery of milk to demand a year down the track. It might show strong planning, but it shows poor revenue realization.

Steve Taylor is president of Distributed Networking Associates and publisher/editor-in-chief of Webtorials. Larry Hettick is a principal analyst at Current Analysis.