Extreme joins PBT bandwagon

Extreme Networks is joining the ranks of equipment vendors chasing the demand for Provider Backbone Transport (PBT) networking products.

Extreme plans to offer PBT as a software upgrade to its Black Diamond 10K and 12K carrier Ethernet switching platforms. The company hopes to begin shipping that software in early 2008.

Though that may be a long wait, Extreme pointed out that PBT standards might not be complete until mid-2008. The Institute of Electrical and Electronics Engineers will begin work on PBT standards this March.

“Some [carriers] will wait for PBT standards to solidify,” said Peter Lunk, director of Extreme’s service provider marketing. “Other customers are asking, ‘What can we do in the mean time?’”

A connection-oriented technology, PBT tags traffic with media access control (MAC) headers to create Ethernet service tunnels with dedicated bandwidth. Those point-to-point tunnels are meant to alleviate the need for more expensive routing architectures based on multiprotocol label switching, which PBT proponents argue are more complex. At the moment, however, PBT also comes with limitations on its provisioning and processing scalability.

Nortel Networks led the charge on PBT, announcing the technology as part of its product portfolio last summer. Its popularity bloomed early this year when British Telecom chose PBT gear from Nortel and Siemens for its next-generation network.

Ciena recently acknowledged PBT was on its product roadmap, and in February Meriton Networks announced a new transport platform combining PBT with wavelength-division multiplexing.

Though Extreme, like Meriton, is focusing on PBT in transport networks, Extreme won’t include WDM in its home-grown products. Any such optical elements would come as separate products through the vendor’s partnerships with Adva Optical Networking and Ericsson.

“The Meriton folks will have a lot of software work to do,” Lunk said. “How much do you really want to bite off as one company?”

Like Nortel, Extreme imagines carriers using PBB and PBT simultaneously in different parts of the same switch: PBT for high-bandwidth transport trunks and PBB where multicasting may occur. Extreme’s 10K and 12K platforms have been shipping with PBB technology for about a year, the company said.