Unisphere adds voice for ATM

Unisphere Networks Inc. this week is unveiling support for ATM on its media gateway, enabling service provider customers to support voice over ATM.

At the Voice on the Net (VON) show in Atlanta, Unisphere will introduce an ATM module for its SMX-2100 media gateway, which already supports time-division multiplexed (TDM) voice and voice over IP. The ATM blade will let the SMX-2100 support voice over all major types of carrier infrastructure.

The media gateway sits between a traditional public phone network and a packet network, translating traffic between the two under instructions from software running on a softswitch, such as Unisphere’s SRX-3000.

The ATM capability is important to larger existing local carriers to offer packet voice, says Jim Lawrence, an analyst with Stratecast. These carriers have set up ATM-based networks for data services, and may want to offer voice over the same network to save costs. To migrate from TDM to ATM voice requires media gateways that can handle TDM and ATM, he says.

Many start-up carriers that base their networks on IP require TDM and IP interfaces. But these newer carriers are operating on borrowed money and may be strapped for cash to buy voice gear, Lawrence says.

“Right now, there is a reduced set of customers” for the Unisphere media gateway, Lawrence says.

So the new ATM capability may give sales of Unisphere’s media gateway a shot in the arm because it might appeal to incumbent carriers that have more money to spend, he says.

The two-port OC-3 card supports private virtual circuits, switched virtual circuits and the ATM Adaption Layer Types 1, 2 and 3 standards. It will be available by year-end.

Unisphere is also announcing software for its ERX switch router and media gateway that lets the media gateway recognize and help manage network congestion. Without this capability, routers between the media gateways and the core of the network would be the first devices to know about congestion.

This Rich Media Feature Pack for the Unisphere media gateway uses Multi-protocol Label Switching to learn about congestion. It lets the gateway set the type of service bits in IP packets so they receive appropriate priority as they pass through routers in the network, a process Unisphere calls Voice Express Queuing.

This capability is essential for delivering good quality voice, Lawrence says, but no standard is set. “There isn’t any simple way to do it,” he says.

Unisphere is also announcing at VON software for its SRX-3000 Softswitch that keeps calls alive during certain hardware failures. The softswitches operate on Sun servers that can be clustered to back each other up. But currently if one fails, calls are dropped and have to be reestablisihed.

Unisphere’s Resilient Telco Platform (RTP) is middleware that provides software-based call backup to hardware failures. The failover is undetectable to callers, Unisphere says.