US 7,260,097 B2 Aug. 21, 2007
(54) LABEL CONTROL METHOD AND
APPARATUS FOR VIRTUAL PRIVATE LAN
(75) Inventor: Liam Casey, Ottawa (CA)
(73) Assignee: Nortel Networks Limited, St. Laurent, Quebec (CA)
( * ) Notice: Subject to any disclaimer, the term of this patent is extended or adjusted under 35 U.S.C. 154(b) by 1059 days.
(21) Appl. No.: 10/265,621
(22) Filed: Oct. 8, 2002
(65) Prior Publication Data
US 2003/0142674 Al Jul. 31, 2003
Related U.S. Application Data
(60) Provisional application No. 60/352,888, filed on Jan. 30, 2002.
(51) Int. CI.
(52) U.S. CI 370/392; 370/401
(58) Field of Classification Search 370/408,
370/238,236,401,393,389; 709/249 See application file for complete search history.
A network can be organized for providing virtual private LAN segment (VPLS) services to customers into a network core and an associated number of logical provider edges. Each logical provider edge is partitioned into a plurality of Edge-PEs and a Core-PE. Customers connect to the EdgePE. The Edge-PE maintains a context (a virtual bridge) for each customer VPLS it serves, VPLS service is realized by a full mesh of so called virtual circuit (VC) tunnels between virtual bridge ports. Each VC tunnel is identified by 3 VC labels in each direction, the first label is used in the encapsulation of customer traffic from the ingress Edge-PE to the ingress Core-PE, the second from ingress Core-PE to egress Core-PE and the third from egress Core-PE to Egress Edge-PE. The mechanisms for the allocation of the label values to and how the label values are used provide a realization of VPLS service that is scalable and easy to administer.
22 Claims, 6 Drawing Sheets