BellSouth brings COS to VoIP

BellSouth is claiming to be the first telecom provider to add end-to-end class of service to its Managed Network VPN service, enabling business customers to guarantee the quality of converging services, especially voice, over an IP network.

"We are implementing [COS queues] all the way through the core of our network," said Brett Chyatte, senior product manager, for Network VPN at BellSouth. "We don't just do policing on these queues on the edge of the network, we maintain them all the way through the network. There is a separate latency queue for voice that is in the hardware, across the backbone, so that real-time traffic is protected from congestion."

The new premium-level service is attractive to companies combining their voice and data services onto a VPN because it provides assurance, with service level agreements and automatic credits, that voice traffic will not be affected by data congestion.

The claim to be first in implementing this technology is based on conversations with its equipment vendors, including Cisco Systems and Juniper Networks, and with other network operators with whom BellSouth plans to interconnect its networks, he said.

"Our vendors have had to bring in their key developers--we are the first ones to push them to this level of implementation," Chyatte said. "We are confident that they are tackling these issues for the first time with us."

BellSouth will now offer four different classes of service: real-time, interactive, priority business and best effort. Customers can choose on a network-wide or a site-by-site basis what level of service they wish to buy. "This is considered a premium class of service--you can buy it in various packages," he said. "We are charging a premium for delivering higher service capabilities, because we engineer the network differently for those customers."

The other option for guaranteeing the quality of VoIP, regardless of congestion on a bursty data network, is to provide massive extra bandwidth, creating network utilization rates as low as 20%, Chyatte said. That approach is not cost-effective for customers.

He does expect to see other service providers following in BellSouth's footsteps but couldn't comment on when there might be carrier-to-carrier interconnection that preserves the COS capabilities.