Softswitches Head for the Last Stretch:

Posted 06/01/2001

Softswitches Head for the Last Stretch:
Are Class 5 Replacements Ready to Run?

By Paula Bernier

Most softswitches started life in Internet offload and Class 4/tandem switching applications. Now softswitches are gearing up to go the last mile.

Telcordia Technologies Inc. (www.telcordia. com) was the first vendor to come out with a softswitch targeting Class 5 applications. Most softswitch vendors, such as Sonus Networks Inc. (www.sonusnetworks.com) and Telica Inc. (www.telica.com), tend to focus on Class 4 applications, because the initial focus for IP telephony has been on long-distance arbitrage.

But unlike those companies, Telcordia decided to focus solely on Class 5, says Peter Schorsch, Telcordia's director of marketing. It's not surprising that Telcordia would be the leader in this space considering the company, previously known as Bellcore, was the research and development arm of the Bell LECs.

Telcordia does call processing and features in the softswitch, but it does not offer gateway functionality in its product. Schorsch says the company believes instead in putting the gateway (which converts digital to analog and vice versa) at the edge of the network to bring IP all the way to the customer. That means the customer, at a future date, will be able to self- provision, explains Schorsch. But before that can happen, the industry needs to see line-side gateways that are more affordable and available through retail channels, he says.

Sprint Corp. (www.sprint.com) uses Telcordia's Class 5 softswitch today in bundled consumer and business applications as part of its Sprint ION initiative. As of late March, Sprint was in seven markets with the Telcordia Call Agent Class 5 softswitch offering VoIP. Also this spring, the carrier was in the midst of turning up an additional seven markets with the softswitch-based service. At the same time, the company was adding hub software to convert from VoIP to voice over ATM, which Sprint's Frederick Harris, vice president of design, applications and services, says would allow it to scale up and was part of the plan from its inception.

Meanwhile, CTC Communications Group Corp. (www.ctcnet.com) was in betas in March with six customers for Class 5 replacement with IADs. It expects to go to commercial shortly.

Harris says the carrier picked Telcordia's softswitch because it was the only Class 5 softswitch on the market. Other softswitches lacked the same ability to scale features and interfaces for such things as connecting with a long-distance switch or to offer dual tone multifrequency (DTMF, which provides dial tone), he says.

The Sonus Class 4 product handles calls, does service control point (SCP) lookups, supports calling cards and has some other functions, Harris says, adding that the company now is moving into Class 5. "The difficult part is [Sonus] did the easy part first," he says.

One challenge of using a softswitch for Class 5 deployments is that the new packet-based voice networks use a wide variety of protocols to communicate with various devices. For example, a softswitch or other device would use SS7 to interface with the PSTN for call termination on a standard telephone. But the same softswitch-based network would need a different protocol, like media gateway control protocol (MGCP) or SIP to communicate to a server or endpoint within the network. Meanwhile, on the PSTN, all communications between endpoints and network equipment like servers or switches; or between endpoints and network-based devices simply would be via SS7.

Adding to the potential of problems is that a MGCP call also requires many more messages for call setup and teardown compared to an SS7-based call, which requires only five messages, says Bob D'Eletto, strategic business development manager for Agilent Technologies Inc. (www.agilent.com). He says trouble tickets often outnumber customers in these new packet voice networks. To address these problems, Agilent recently came out with the NGN Analysis System, a call-monitoring tool that is intended to help service providers make softswitch-based networks as dependable as PSTN networks.

The NGN software runs on a computer that plugs into the softswitch, SIP proxy or gatekeeper to pull signaling from all calls, creating a call flow record and keeping a record of each call in a separate folder. It also marks failed calls. The interface for the system is web-based, and the system is distributed so multiple users can access it. The first release of NGN began shipping April 1. But Agilent plans to integrate its other products, such as NETeXPERT, Firehunter, acceSS7 and acceSS7IP, in with the NGN in future releases to support SLA monitoring, performance management, configuration management, voice quality testing and more. Sprint ION is the first announced customer of NGN.

Softswitch vendors are now focusing more attention on operations, administration, management and provisioning, according to Joe Mele, vice president of open network solutions at Lucent Technologies Inc. (www.lucent.com).

"Initial products were very light" in that area, Mele says. "Now vendors are focusing more attention on interfaces and element management systems, and I think what it comes down to is reliability."

Softswitches also are now far more scaleable than they were in earlier generations of the products, he adds.

"A year ago, it wasn't clear to me that if you put one of these [softswitches] in, it would work." Now softswitches like that of Lucent can do between 144,000 and 5.25 million busy-hour call attempts, which is in the neighborhood of what a PSTN Class 5 can do, he says.

Sprint's Harris notes that media gateways--the circuit-to-packet conversion devices typically found in softswitch networks--also are becoming more reliable and robust. But in the past, gateways had a variety of problems, including difficulty communicating with both a softswitch and a LEC network simultaneously, he says.

For example, if a person was accessing voice mail and another call came in, the gateway might drop the call. Harris says dropped calls also were sometimes a problem when a customer was accessing voice mail and a LEC then started pinging the line for a test.

"It's not that it's complex, it's just that it does a hundred million different things," Harris says. He notes that a 100,000-line exchange on the PSTN commonly has thousands of trouble tickets each day resulting from such problems as an inside wiring frame, cabling and various other issues.

In addition to signaling and troubleshooting concerns, Harris says Class 5 switches must also support 911 today and, in the future, things like CALEA (the Communications for Assistance Law Enforcement Act, which requires carriers to assist law enforcement in electronic surveillance).

While Sprint has been using the Telcordia Class 5 solution and related equipment for 18 months, other vendors are largely in trial phase with their Class 5 softswitches.

Uniphere Networks Inc. (www. unispherenetworks.com), for example, in March had completed Class 5 customer trials of its BroadSoft platform. But Brian Silver, vice president of voice strategy at Unisphere, says those deployments were for business Centrex, not lifeline, so if there was a 911 call, the equipment would route it to the PSTN.

"The market is very immature from the softswitch perspective," says Doug Wadkins, senior manager of customer solutions for Cisco Systems Inc. (www.cisco.com). "We're not in GA [general availability] stage with our Class 5 Cisco BTS 10200 Softswitch, but we have solved E911." Cisco expected to make its Class 5 solution generally available in October, and is now in trials with BroadRiver Communications (www. broadriver.com) and Cbeyond Communications (www.cbeyond.net) with the product.

Convergent Networks Inc. (www. convergentnetworks.com), meanwhile, expected to have a softswitch with Class 5 functionality available this quarter. Joan Lockhart, director of corporate marketing at Convergent, says the company's product is being used by 11 customers for Internet offload and/or trunking, but the company now hopes to conquer the broadband access space. For some customers, like Michigan-based CLEC ACD.net (www. acd.net), doing Internet offload enabled them to justify the investment in the softswitch, she says.

Sonus is also now seeing its customers begin to migrate from Internet offload and Class 4/tandem applications to Class 5 as well, says Terri Griffin, vice president of INIP marketing for the IntelligentIP division at the vendor.

"Our switch is ready for prime time because it's already widely in deployment, mostly in Class 4," she says. "The question is, are customers ready with Class 5?" TalkingNets (www.talkingnets. com) uses Sonus products for Class 5 replacement, she says. But most Sonus customers, like Global Crossing Ltd. (www.globalcrossing.com), Qwest Com- munications International Inc. (www. qwest.com), Time Warner Telecom Inc. (www.twtelecom.com) and XO Com- munications Inc. (www.xo.com) are more interested in Class 4 or Internet offload right now.

Among the Sonus products are the PSX6000 high-capacity proprietary softswitch; the GSX90000 gateway with call control; and the IntelligentIP (INIP) softswitch with call control, which the company got through its telecom technologies inc. acquisition, and which is best positioned for interoperability with other vendors' products.