THE FUTURE AS SEEN THROUGH TECHNOLOGY

The Optical Interworking Forum will introduce later this year an implementation agreement, or IA, to help carriers automate optical network provisioning, dramatically shortening the time it takes to light a cross-country link.

When a carrier needs to provision an optical connection today from, say, New York to Los Angeles, a network engineer typically finds a route by identifying available capacity in contiguous segments along the way and manually reserving it: a path from New York to Cleveland, from Cleveland to St. Louis, and so on. Sometimes they reserve a path halfway there only to discover the most direct route is no longer available, forcing them into more convoluted trajectories.

“That starts to make the path less optimal,” said Jonathan Sadler, chairman of the OIF's architecture and signaling working group, as well as Tellabs' senior principal engineer.

It's also time-consuming, especially for carriers that maintain divisions within their own networks (for example, one de facto network east of the Mississippi River and one west, each with its own operations support apparatus). A cross-country optical circuit might take hours or even days to provision, Sadler said. With the IA the OIF is working on, it might take seconds.

The E-NNI 1.0 Routing IA — born from three years of interoperability tests in carriers' labs and based on the open shortest path routing protocol and generalized multiprotocol label switching routing extensions — will manage network inventories and resources by defining information shared by automatically switched optical network elements.

The IA includes a network-to-network interface to bridge the internal divides between carriers' East Coast and West Coast networks, but the same interface will also allow traffic handoffs from one carrier to another.

And by moving network inventories online, the IA will make them more accurate and up-to-date, Sadler said. “When circuit design is done today, it gets sent to the provisioning people, and many times when they go to provision it, they find the resource that was specified in the work order is actually in use for another circuit,” he said. “Then the design has to go back to the circuit engineering group and be redesigned, which creates more delay. The [OIF] routing protocol allows you to get a current snapshot of the actual inventory usage, so there's less likely to be stranded resources. It also knows that it cannot reuse a circuit that's already in use.”

The OIF has assigned a more than 20-member group to develop the new IA. When its work is complete later this year (the group kicked off its development effort formally in February but says the wealth of past interoperability tests will allow this IA to be completed quicker than most), the 6-year-old OIF will submit the new IA to more prominent standards groups such as the Internet Engineering Task Force and the International Telecommunications Union for adoption. If all goes well, Sadler hopes network planners never get stranded again.