Comcast Kicks Tires On 100-Gig Optical Links

Comcast this week is conducting what it claims is the first test of 100-gigabit-per-second optical networking equipment carrying live Internet traffic over a production fiber infrastructure.

The 100-Gbps trial connects Comcast facilities in Philadelphia and to McLean, Va., running over the operator’s metro and long-haul fiber links. Comcast is using preproduction versions of Nortel Networks’ 100-Gbps interface cards, running in the vendor’s Optical Multiservice Edge 6500 system.

“This is a significant milestone in readying for the deployment of 100-gigabit optics,” John Schanz, executive vice president of national engineering and technical operations for Comcast (pictured), said in an interview. “It’s an enabling building block for going to wideband.”

“Wideband” is the shorthand way Comcast and others in the industry have been referring to DOCSIS 3.0, the last-mile cable modem technology that can bond multiple channels together to provide download speeds of 100 megabits per second or more. Comcast expects to offer DOCSIS 3.0 service across 20% of its nationwide footprint by the end of 2008.

Comcast is conducting the 100-Gbps optical test in conjunction with the 71st meeting of the Internet Engineering Task Force (IETF), the primary technical standards-setting body for the Internet, this week in Philadelphia.

Schanz said all the Internet traffic from the IETF conference is traversing the 100-Gbps link. “It is the first live demonstration of real traffic tying into a real network over 100-Gig wavelengths,” he said.

Comcast’s trial follows a test of the technology by key rival Verizon Communications, which has said it hopes to deploy 100-Gbps optical gear to sometime early this year.

In November, Verizon said it completed the first field test of 100-Gbps optical transmission on a live 312-mile network route between Tampa, Fla., and Miami. The telco’s test used a live video feed from the FiOS TV network, and optical equipment from Alcatel-Lucent.

Comcast’s test is different, according to Schanz, for several reasons: It's running live traffic, and the 100-Gbps wavelengths in the Comcast trial are running over the same physical fiber as its existing 40-Gbps wavelengths, which are handled by Cisco Systems gear.

“It’s not on some dedicated facility,” he said. “It’s on our production fiber, next to other lambdas.”

In addition, Schanz said, Comcast believes it's the first test of 100-Gbps wavelengths with reconfigurable optical add/drop multiplexer (ROADM) photonic components.

Nortel’s 100-Gbps offering will not be ready for commercial deployment until the second half of 2009.