The Optical Interworking Forum (OIF) has approved an implementation agreement (IA) designed to ease the provisioning of optical networks.

Announced last May, the External Network-Network-Interface (E-NNI) Routing IA defines key requirements for the exchange of network topology and other information from one network segment to another. The group hopes it will reduce the time it takes to provision cross-country optical circuits from hours or even days to just seconds.

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.

The OIF hoped to alleviate this problem in part by moving network inventories online, making them more accurate and up-to-date and avoiding the possibility of traffic becoming stranded. The OIF’s E-NNI IA, made possible through interoperability tests in carriers' labs between 2003 and 2005, is based on the open shortest path first (OSPF) routing protocol and generalized multiprotocol label switching, or GMPLS. It was designed to help carriers manage network inventories and resources by defining information shared by automatically switched optical network elements.

The IA was approved in January at the OIF’s first technical meeting of 2007.