New technologies target metro networks

New metropolitan area services and better bandwidth for Canadian enterprises are on the horizon.

At least one major Canadian carrier is preparing to trial dense wavelength division multiplexing (DWDM) gear from Nortel Networks and vendors are coming up with more efficient ways to haul data between sites within metropolitan areas.

After completing successful lab testing of Nortel’s OPTera Metro DWDM networking product, Bell Canada will conduct further OPTera trials over the next several months. If all goes well, Bell says network deployment of OPTera will take place within the next six months.

DWDM multiplies the bandwidth of a single fibre by dividing it into channels of different coloured light. The OPTera Metro product, for example, provides more than 32 protected wavelengths for a capacity of 80Gbps per fibre.

Don Smith, vice-president and general manager of OPTera solutions for Nortel, noted OPTera is designed to run in a ring, like SONET systems, so if one fibre is cut, data can be re-routed over the other portion of the ring. Also, the wavelengths are protocol-independent and can carry any traffic natively.

Perhaps best of all, from a carrier’s perspective, a wavelength can be made to carry a different traffic type via keyboard command with no actual physical provisioning.

“We think DWDM is a bandwidth expansion tool and creates new services related to that bandwidth,” Smith said. “The term we like to use for what it creates is forecast-tolerant networks.”

Enterprises with large data centres should find DWDM carrier services appealing, according to Smith, because it gives them a protected, managed wavelength. And if the firm wants to expand a link from fast Ethernet over DWDM to gigabit Ethernet over DWDM, all it has to do is call its carrier and the change can be made without much delay.

“There’s clearly an opportunity in metro,” Smith said. “That opportunity’s driven by the growth in bandwidth, it’s driven by IP, driven by the Internet, intranets, e-commerce and the like.”

Bob Hafner, an analyst with Gartner Group Canada Inc. in Mississauga, Ont., said DWDM should find a home in metropolitan area networks.

“It’s an interesting way to provide quite a bit more bandwidth at a relatively low cost,” he said. “What it does is change the economic model.”

Large enterprise customers looking to converge their voice and data services onto one network would make ideal DWDM service candidates, Hafner said.

“Right now, you might say most companies can be satisfied with DS-3 capabilities. That generally doesn’t include the 30, 40, 50, 100 trunks they have in voice traffic.”

Like Nortel, Cisco Systems Inc. is aiming to boost metropolitan area networks. Recently, the networking giant unveiled its Dynamic Packet Transport (DPT) family of products. The DPT products are the first technology to emerge from Cisco’s 1997 acquisition of Skystone Systems of Ottawa.

DPT is a SONET technology. Carriers currently deploying SONET have to deploy add-drop multiplexers and then attach network gear to those multiplexers, said Tony Kleinschroth, systems engineering manager with Cisco Systems Canada Co. in Toronto.

“What DPT does is basically meld the networking gear and the add-drop multiplexers into a single box,” Kleinschroth said. “So I don’t need an extra layer of add-drop multiplexers or network complexity for metro area services.”

DPT also works with Cisco IOS, so carriers can run differentiated services across the metropolitan area.

“For the business end user, this is application-enabling technology,” Kleinschroth said. “So Web traffic might have one prioritization, but business apps would have another.”

DPT line cards for the carrier-class Cisco 12000 GSR will be available this month, with cards for the 7500 series router port adapter appearing in April.

Kleinschroth said the response from Canadian carriers has so far been “solid,” but couldn’t comment on any existing or impending deployments.