While debate remains over how XML-savvy legacy carriers are, analysts agree that future application services in broadband nets will be provisioned by XML.

"I am not aware of a single carrier that doesn't keep XML central in development plans," said Lorein Pratt, program manager at Stratecast Partners.

The trend in mergers and acquisitions — like IBM's move in snaring DataPower and Intel Corp.'s summer acquisition of Sarvega Inc. — is meant to enhance application-layer services in a data center environment. By adding Sarvega or DataPower appliances to server clusters, central servers could perform message routing and security functions called from Extensible Markup Language, Simple Object Access Protocol or legacy business protocols from the likes of Oracle Corp.

XML message routers from Canada's Solace Systems Inc., which use an architecture similar to what Cisco Systems Inc. announced for its Application-Oriented Networking, want to extend these enterprise services to a carrier environment.

The application-layer offerings in hardware are arriving just as carriers are trying to meet the expectations raised by the nebulous promise of IMS systems, the centralized gateway and service-provisioning schemes where all data, voice and video services are aggregated and carried over a unified IP network. In reality, IMS is the latest acronym to describe a soft-switch function in carrier networks, albeit one based primarily on Session Initiation Protocol (SIP) clients rather than Media Gateway Control Protocol.

Since last summer's Supercomm show, carriers and hardware providers alike have talked of IMS as though it were a new concept, though the aggregation of circuit-emulated traffic over IP has been assumed since the first generation of soft switches landed in the late 1990s. What is new is the provisioning of IMS services using XML and application-layer protocols.

Defining IMS
Venture Development Corp. predicted a month ago that widespread adoption of IP-based IMS will lead to the death of SS7 signaling and that IMS will represent a $2.6 billion market by 2008. Telcordia executives say that all depends on what is meant by IMS adoption. The company admits that its own Maestro IMS software framework is a repackaging of such "service logic" software elements as an application server developed for general IP soft switching and a real-time charging element to simplify service charging across physical networks.

"It's not certain when you can say we have reached a universal reliance on IMS, because there isn't a true consensus on what that means," said Grant Lenahan, executive director and business unit strategist in Telcordia's new IMS services group. "At a minimum, you have to be able to define and launch a new service, as well as provide service assurance using an IP infrastructure without requiring a new network-management system."

Douglas Fantuzzi, group senior vice president at Telcordia, said that the end-user assumption driving IP broadband services is that services can be provisioned in the same way across wireless, wireline and cable-TV networks. Creating service through the application layer may mean that voice quality and packet latency get measured in approximately the same way across networks.

"We're not going to see absolute similarity of billing methods or quality-of-service measurements across, say, a wireless provider and a cable provider," Lenahan warned. "Different carriers rely on different resource-reservation methods and different access technologies. The best you will see is a similar way to create and provision service from the application layer."