Technology differences aside, the two approaches can work together to deliver telco services

In this corner, IP multi­media subsystem: the industry-backed approach to IP-based service creation. Across the ring, Web services: the challenger that aims to upset the perceived service status quo.

Over the past year, the bell has rung in this bout. But what happened when the two competitors stepped forward to engage in the marketplace? Not a lot of action, unfortunately, but also a clearer understanding that this “battle” isn’t really a fight at all.

When it comes to services, IMS does some things well; Web services have their own advantages. And while it’s not entirely clear to what degree the two service styles ultimately will complement each other, what is clear is that they can — and in some early deployments do — work together to deliver new telco services. Just as clear: IMS is at last making a mark at the core of emerging IP networks, improving vendor interoperability, separating services from the network and providing a best-practice architecture for next-generation networks — really the end point for IMS all along.

The bigger challenge, service providers have found, is not the technology story around IMS and Web 2.0/Web services, but the business tale of the tape. The typically more real-time, transaction-oriented services that IMS enables fit existing telco business models; by comparison, more decentralized, often third-party–pay Web services represent a completely new way of doing business for today’s telecom operators.

“Web players have a lot less to do when they launch a service,” said David Withington, director of marketing for Alcatel-Lucent’s application division. “They don’t have to bill a customer or worry about customer care; there’s no [quality of service] requirements. The issues around IMS services are more about the business model and the customer brand expectation than around the technology.”

Although IMS is far from being in full bloom, deployments are beginning. Sources typically painted the deployment story as still experimental and small-scale in nature. Contracts for more full-blown deployments are coming down the pike — most frequently in Europe, less aggressively in the U.S. — but those networks won’t fully roll out until next year at the earliest.

The service focus for early deployments is very simple as well and focuses mainly on real-time services: Class 5 voice service replacement, new voice-over-IP (VoIP) networks, some video-sharing and IPTV-based services. Those types of services are classic carrier offerings — applications that Web providers would find hard to compete with, especially if key IMS concepts such as QOS are taken into account. With QOS in its quiver, a telco can begin to deliver additional IMS-enabled services such as parental controls, targeted content and advertising, and tiered bandwidth access — areas that “best-effort” Internet players will be hard-pressed to match.

If IMS looks to have a role in next-generation VoIP, IPTV and real-time messaging services, where do Web services fit? Telcos clearly are experimenting with Web services, both at the end user service level and — more often and with more impact — in the telco back office as a key component for integrating and exposing core carrier capabilities, sources said. The key enabling platforms here are the application server and the even more horizontal service delivery platform, which create an abstraction layer that enables carriers to expose core network and back-office functionality via Web services– and Java-wrappered interfaces.

That opens up telco app creation to a much broader range of developers, said Ajay Joseph, chief technology officer for iBasis, which delivers international minutes as a carrier’s carrier and runs its prepaid calling card business via a network largely built to IMS standards — a rare instance of a true production IMS network.

“Where it once took several different teams to build a new feature or service, we now can do it much more quickly,” Joseph said. “All our development is happening in Java; network capabilities are extracted upward so that developers that are not network-savvy can still take advantage of them.”

iBasis isn’t dogmatic about IMS; it built its network to IMS philosophies incorporating standard elements such as session border controllers, media gateways and servers, and standard signaling elements. One element it left out — which seems to be a common theme among early deployers — is the centralized home subscriber server (HSS) database, a decision Joseph said came down to complexity and pricing issues.

In the end, carriers will do best to take a pragmatic approach to both IMS and Web services, using both where they fit best to wring the most value out of tomorrow’s IP-based networks, sources said.

“If you look at the IMS core, below the service layer — elements like the service broker, the [service capability interaction manager] layer, the application server — those elements are getting deployed today. They will do very well at doing real-time applications like VoIP and video sharing,” said John DePietro, director of IMS product management for Starent, a mobile packet data and IMS signaling vendor.

“Now at the service layer, the question is how do I integrate or mash up those capabilities with Web 2.0?” he said. “The interesting thing about application servers and service delivery platforms is that those are all Web services-based anyway. That creates a blended service [IMS plus Web 2.0]; the faster operators can get to services like that, the better off they’ll be.”

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