Optical/IP Networks

Sonus Fills BT's IMS Hole

By bringing Sonus Networks Inc. (Nasdaq: SONS) on board as a preferred supplier for its £10 billion 21CN project, BT Group plc (NYSE: BT; London: BTA) is solving one of its more thorny next-generation network problems -- continuity of service as it migrates towards its new network and switches off its PSTN. (See Sonus Gets BT 21CN Win.)

It also gives Sonus a role it was expecting to be handed more than two years ago.

Sonus announced late Thursday that it will provide BT with its ASX access server, which performs the Access Gateway Control Function (AGCF) in the IP Multimedia Subsystem (IMS) world. And that's a function that has been causing BT some procurement issues.

The AGCF communicates with media gateways at the edge of the network, using a protocol such as H.248, and interacts with other IMS network elements using SIP (Session Initiation Protocol). It enables a carrier to emulate PSTN and ISDN services in its IMS by mapping the services into SIP. (See Tispan: IMS Plus.)

In BT's 21CN network, the AGCF will sit between the multiservice access nodes (MSANs) and the carrier's new IP network elements.

It’s a vital cog in BT's network transformation strategy because it will enable all service providers that use BT's network (of which there are hundreds) to have access to the same set of services, whether their customers are using legacy services or new IP services.

As Joe Kelly, the communications director for the 21CN project, says, "Simply put, it helps build a bridge between the 20th century network and the 21st century network, and means that all service providers will have the same level of capability."

That's important to BT's Wholesale division because it is required by U.K. telecom watchdog, Ofcom , to deliver equality of service to all the operators that hook into, or ride on top of, BT's infrastructure.

Despite its vital role in the 21CN, BT had been struggling to find an AGCF product to meet its needs.

During an IMS presentation at the NXTcomm show in Chicago in June this year, BT executive Malcolm Wardlaw, one of the 21CN's five principal architects, noted that there were "limited vendor opportunities [to source AGCF functionality]. What I have seen only goes half way -- there is always something missing."

So which of BT's announced 21CN preferred suppliers should have been meeting BT's AGCF needs? Ericsson AB (Nasdaq: ERIC).

The AGCF is one of the functions BT specified for the 21CN's Intelligent Nodes (i-nodes), designed to manage voice services in its new network. And when the carrier announced its list of preferred vendors in April 2005, Ericsson was named as the sole i-node supplier. All other parts of the 21CN had more than one supplier. (See BT Unveils 21CN Suppliers.)

Ericsson, though, has been unable to meet BT's AGCF requirements, even though it said it would work with third-party suppliers to deliver to BT's i-node specifications. (See Ericsson to Bring Partners to 21CN Party.)

And according to sources, BT has having a few problems sorting out its 21CN voice service challenges. (See Upheaval at BT's 21CN?)

So now Sonus is an i-node preferred supplier, too -- and that's a role it was expecting to win back in 2005.

At that time it was a partner of Marconi, which had been widely expected to land MSAN and voice service support roles in 21CN. But Marconi was frozen out of the 21CN deals, and, ultimately, broken up, with the majority of the company acquired, ironically, by Ericsson. And that left Sonus without its expected 21CN gig. (See Analyst: Marconi in Line for 21CN , Marconi & Sonus Team for Next-Gen, Marconi in Turmoil, and Ericsson Buys Bulk of Marconi.)

But while Sonus is excited about the renewed opportunity to play a role in 21CN, it still has to prove itself. BT's Kelly explains that "Sonus will be required to do a degree of development work so that its technology works appropriately for BT. Sonus needs to make its product compliant with the unique regulatory requirements" placed on the 21CN.

And will Sonus be BT's only AGCF supplier? Kelly is a bit more coy about that. "Sonus is the only company we have signed a contract with," he says, while acknowledging that there are a number of vendors in the market with AGCF capabilities. Vendors other than Sonus known to have developed AGCF functionality include Alcatel-Lucent (NYSE: ALU), Thomson S.A. (NYSE: TMS; Euronext Paris: 18453)'s Cirpack business, and Huawei Technologies Co. Ltd. . (See Alcatel Embraces Tispan's IMS Cirpack Unveils IMS Gear.)

No financial details were announced, but the deal is expect to be worth several tens of millions of dollars to Sonus over a number of years.

— Ray Le Maistre, International News Editor, Light Reading

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