Sonus Networks Inc. (Nasdaq: SONS) has spruced-up its softswitch with border control features that it hopes will appeal to carriers looking to pass traffic back and forth between different IP networks (see Sonus Offers Session Controller Features).

It’s a hot new area that has attracted at least half a dozen specialist companies, but Sonus claims its technology goes a step further than the pack.

As voice over IP (VOIP) becomes more mature, there are issues on the carrier side when one operator attempts to peer with another, such as overcoming firewall and NAT (network address translation) traversal that regular VOIP equipment cannot handle.

VOIP session controllers, built by Acme Packet, Ingate Systems AB, Jasomi Networks, Kagoor Networks, Netrake Corp., NexTone Communications Inc., and Ridgeway Systems & Software Inc., take on this challenge (see Session Controllers Kick Off).

”This is the very basics of peering,” says Michael Rubin, director of product management at Sonus. “The more complicated part is handing off traffic to another carrier with different SS7 signaling.” He says Sonus offers 25 different SS7 variants it started developing six years ago with Global Crossing Holdings Ltd.

“Then the market went way south and we focused elsewhere… Peering wasn’t important, as everyone was focused on keeping their own networks alive,” Rubin says.

The picture is much better today, he observes. Now operators are looking to hand off traffic and offer the same services at the edge of the VOIP network as they do at the edge of the TDM network.

“Session control is more than just overcoming the infrastructure boundaries,” Rubin says. In addition to the security and control functionality provided by a standalone session controller, Sonus says its softswitch offers an all lines busy service and an 800 menu system that enables customers to get information from the company they are calling without having to wait for a representative.

A current Sonus customer has bought the technology but declines to be named, and several others are testing it, according to Rubin.

Acme Packet, NexTone, and the rest of the session controller gang have outlined plans to offer various types of SS7 handoff capabilities in their products throughout next year.

VOIP peering might sound nifty, but it hasn’t become a major issue yet, as VOIP adoption has been slow, and most VOIP deployments to date don’t bring the firewall problem to the fore. For the most part, enterprise VOIP implementations have either been restricted to “islands” of LAN deployments or, at most, have connected these islands via dedicated, private, wide-area links.

However there’s a long-term vision whereby the Internet replaces the public switched telephone network and carries a mix of voice, video, and data; and in such an environment, session controllers are expected to play a crucial role.

Meanwhile, Sonus appears to have turned an important corner in its core softswitch business. Today, its customer list includes Verizon Communications Inc. (NYSE: VZ), Deutsche Telekom AG (NYSE: DT), Qwest Communications International Inc. (NYSE: Q), and AT&T Corp. (NYSE: T). According to Steve Levy, managing director, wireline equipment equity research, at Lehman Brothers, Sonus worked for three years to get the AT&T contract.

This is a customer list very different from the one in 2000 and 2001, when Sonus was selling a majority of its products to new telephone carriers that were constructing massive fiber optic networks. When the telecom market collapsed, so did many of those new carriers, including major Sonus customers such as XO Communications and Global Crossing.

But Sonus still faces intense competition from incumbent vendors, particularly Nortel Networks Corp. (NYSE/Toronto: NT), which is doing an excellent job selling to its installed base of customers, Levy says (see MCI Vouches for Nortel's VOIP and Sprint, Nortel Ink Billion-Dollar Deal).

”Any deployment with a new build element is good for Sonus. Otherwise, the evolutionary approach plays right into Nortel’s hands,” he says.

For that reason, climbing onto the session controller bandwagon is a good move for Sonus, says Danny Klein, analyst with Yankee Group, as it’s another area in which Sonus can take the lead over the big established companies like Nortel and Lucent Technologies Inc. (NYSE: LU) that are generally slower to adopt new technology, he says.

Alcatel SA (NYSE: ALA; Paris: CGEP:PA), Nortel, Lucent, LM Ericsson (Nasdaq: ERICY), and Cisco Systems Inc. (Nasdaq: CSCO) have yet to announce strategies that address IP peering between carriers. Nortel says it has session controller technology in its softswitches, but it hasn't provided many details in that vein. Siemens AG (NYSE: SI; Frankfurt: SIE) has made a start with a small investment in Kagoor Networks (see Siemens Props Up Kagoor, Cisco Looking for Control?).

— Jo Maitland, Senior Editor, Boardwatch