(12) United States Patent ao) Patent No.: Us 7,382,738 B2
Ravindran et al. (45) Date of Patent: Jun. 3,2008
(54) METHOD AND APPARATUS FOR
COMPUTING METRIC INFORMATION FOR
ABSTRACTED NETWORK LINKS
(75) Inventors: Ravi Ravindran, Ottawa (CA); Peter
Ashwood Smith, Hull (CA); Guo
Qiang Wang, Kanata (CA); Hong
Zhang, Kanata (CA)
(73) Assignee: Nortel Networks Limited, St. Laurent,
( * ) Notice: Subject to any disclaimer, the term of this patent is extended or adjusted under 35 U.S.C. 154(b) by 926 days.
(21) Appl. No.: 10/718,681
(22) Filed: Nov. 24, 2003
(65) Prior Publication Data
US 2005/0111375 Al May 26, 2005
(51) Int. CI.
(52) U.S. CI 370/254; 370/351
(58) Field of Classification Search 370/229
See application file for complete search history.
(56) References Cited
U.S. PATENT DOCUMENTS
5,764,740 A 6/1998 Holender 379/112
6,094,437 A 7/2000 Loehndorf, Jr. et al 370/420
6,104,699 A 8/2000 Holender et al 370/235
A method and apparatus for associating metric information with an abstracted link of an abstracted network map that includes certain network elements (NEs) of a data transport network involves computing routes through the data transport network between the NEs of the abstracted network map. The routes may be computed using the shortest widest path algorithm. The routes from an NE are exchanged with the other NEs of the abstracted network map, so that an edge NE receives the resource availability information of all optimal routes between pairs of NEs in the abstracted network map. The edge NE then transforms the resource availability of a corresponding optimal route into metric information of an abstracted link. The metric information is sent to a client associated with the abstracted network map to permit the client to make routing decisions.
20 Claims, 5 Drawing Sheets