US 7,260,097 B2Granted

Label control method and apparatus for virtual private LAN segment networks

AssigneeNortel Networks Limited

InventorLiam Casey

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Abstract

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 Edge-PE. 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.

Claims22

Dependent claims

A method for providing virtual private LAN segment (VPLS) service in a network comprising a core network and a plurality of logical provider edges (LPEs), the method comprising the steps of:

establishing a full mesh of tunnels between a second plurality of Edge-PEs, each of the second plurality of Edge-PEs having at least one customer site attached thereto, the customer sites being members of a VPLS;
each of the second plurality of Edge-PEs further being part of one of the plurality of LPEs;
each of the plurality of LPEs having at least one Core-PE, forming a third plurality of Core-PEs;
each of the full mesh of tunnels comprising:
a first tunnel segment between a first Edge-PE and a first Core-PE of a first LPE,
a second tunnel segment between the first Core-PE and a second Core-PE, the second tunnel segment traversing the core network, and
a third tunnel segment between the second Core-PE and a second Edge-PE of a second LPE;
receiving at the first Edge-PE, a customer LAN packet from a first customer site having a source address associated with the first customer site and a destination address associated with a second customer site;
encapsulating the customer LAN packet with a first label at the first Edge-PE, the first label being indicative of the first tunnel segment;
forwarding the customer LAN packet on the first tunnel segment to the first Core-PE;
swapping the first label for a second label associated with the second tunnel segment at the first Core-PE;
forwarding the customer LAN packet on the second tunnel segment to the second Core-PE;
swapping the second label for a third label associated with the third tunnel segment at the second Core-PE;
and
forwarding the customer LAN packet on the third tunnel segment to the second Edge-PE;
examining the destination address and forwarding to a customer port at the second Edge-PE.

13 more elements

Dependencies are inferred from the claim text.

Facts

Application: 10/265,621Filed 8 Oct 2002 · us provisional application
Priority: 30 Jan 2002
Published: US 2003/0142674 A131 Jul 2003
Granted: 21 Aug 2007
Term ends: Not estimatedThe source records don’t support an estimate.

Classification4 codes

H04L 45/502
Using label swapping, e.g. multi-protocol label switch [MPLS]: frame based
H04L 12/4633
Interconnection of networks: interconnection of networks using encapsulation techniques, e.g. tunneling
H04L 12/4641
Interconnection of networks: virtual LANs, VLANs, e.g. virtual private networks [VPN]
H04L
Digital communication