Comcast Corp. this month is concluding an Internet-protocol telephony trial in suburban Detroit with TollBridge Technologies Inc. and Arris Group Inc. that could serve as a precursor to how Comcast handles circuit-switch/IP telephony evolution once it takes control of AT&T Broadband.
Comcast inherited the suburban Detroit circuit-switched telephony plant and its 20,000 telephony subscribers from MediaOne Group Inc. Comcast deployed a Cadant C4 cable-modem termination system and a TollBridge TB300 Internet protocol digital terminal as the voice gateway in the fourth quarter of 2001.
This trial is one possible way for Comcast to deploy IP telephony and circuit-switch plant side-by-side once it takes over AT&T Broadband and its more than 1 million circuit switched subscribers later this year.
Mike Horton, senior vice president of marketing and communications at Arris, said Comcast was "trying to make sure they could deploy a carrier grade voice service running through a Class 5 switch."
"The trial was for primary line and for GR 303 protocol," Horton added. "They were extremely successful for this trial. The key was to show carrier class features in the C4. It was a smooth network installation."
"[Data Over Cable System Interface Specification] DOCSIS 1.1 with its dynamic service flow and quality of service capabilities is certainly a key component to providing primary-line telephony," Comcast senior vice president of new media development Steve Craddock said in a statement.
"The carrier class redundancy, performance and design features of the C4 CMTS enable MSOs like ourselves to provide the high availability we need for next-generation services like tiered data and primary line telephony," Craddock said.
Deployment of DOCSIS 1.1-qualified termination systems, like the Cadant C4, is a key step toward MSOs offering IP telephony, on either a standalone basis or in conjunction with deployed circuit-switched architecture.
"We can offer [MSOs] different scenarios," Horton said. "We can offer a great deal of flexibility."
The TollBridge 300 gateway sits between the Lucent Technologies Class 5 switch and the Cadent CMTS. "It's a way to get into [voice over IP] now," said Kevin Woods, vice president of marketing for TollBridge. "Our gateway makes the Class 5 switch looks like a soft switch."
The gateway can handle 1,100 simultaneous phone calls and allows operators to offer IP telephony service that uses existing circuit switches without waiting for replacement soft switches, which Woods estimates is 12 to 18 months away.
Separately, Arris said Adelphia Communications Corp. has deployed seven C4 CMTS chassis and 80 C4 Cable Access Modules.
Adelphia is using the CMTSs in its Greater Lakes region, after having rolled out the product in Ohio and New York.
Arris also said Grande Communications is buying Arris's Cornerstone CMTS 1500 and Cornerstone Cable Provisioning Systems 2000 to deploy tiered data services in Grande's overbuilds in Austin, San Marcos and San Antonio, Texas.