Communications network

• US 6,765,921 B1
• Filed: 06/28/2000
• Issued: 07/20/2004
• Est. Priority Date: 06/28/2000
• Status: Expired due to Fees

• Current Assignee: RPX Clearinghouse LLC (RPX Corporation)
• Original Assignee: Nortel Networks Limited (Nortel Networks Corporation)
• Inventors: Gibson, Mark, Mauger, Roy, Stacey, David
• Primary Examiner(s): Sam, Phirin
• Application Number:
  US09/605,236
• Time in Patent Office: 1,483 Days
• Field of Search: 370/351-356, 370/386, 370/388, 370/389, 370/392, 370/399, 370/395.21, 370/400, 370/401, 370/404, 370/409, 370/469, 370/397, 370/398, 370/395.31, 370/395.42, 370/395.43, 370/405, 370/406
• US Class Current: 370/401
• CPC Class Codes: H04L 45/00 Routing or path finding of packets in data switching networks routing or path finding in wireless networks H04W40/00
• CPC Class Codes: H04L 45/50 using label swapping, e.g. multi-protocol label switch [MPLS]

Abstract

A communications multi-service network arrangement for transporting information packets from a user station to a destination comprises a label switched core network constituted by a plurality of abstract nodes interconnected by tunnels. Each abstract node comprises one or more real nodes. An access network provides user access to the core network. A route across the core network comprises a plurality of label switched path sections specified in terms of a sequence of abstract nodes, the route being identified by a label stack identifying a quality of service capable connection from the end station via the access network to the core network and across the core network to a destination.

Claims

1. A method of routing an information packet over a label switched path from an end station to a destination via an access network and a core network, the method comprising attaching to the packet a label stack identifying a route for a quality of service capable connection from the and station via the access network to the core network and across the core network to the destination, wherein said core network comprises a plurality of abstract nodes interconnected by tunnels and each comprising one or more real nodes, and wherein said route across the core network comprises a plurality of label switched path sections specified in terms of a sequence of abstract nodes.

2. A method as claimed in claim 1 wherein said label switched path sections are incorporated in dynamic multiplexed label switched paths comprising first-stage and second-stage Layer 1 constraint-based routed label switched paths.

3. A method as claimed in claim 2, wherein a new session is multiplexed on to a said dynamic multiplexed label switched path only if the resource constraints of the first-stage and second-stage Layer 1 constraint-based routed label switched paths are satisfied.

4. A method as claimed in claim 3, wherein whereby the resource availability of the second-stage constraint-based routed label switched paths is advertised periodically to the first-stage constraint-based routed label switched paths, the resource availability being used in DM-LSP path selection.

5. A method as claimed in claim 4, wherein a route description comprises an abstract node description of the core network and an IP address of the destination.

6. A method as claimed in claim 5, wherein the access network provides access to a plurality of core networks, and wherein each said core network is associated with a group of destination IP addresses.

7. A method as claimed in claim 6, wherein the labels defining the sequence of tunnels are assigned during tunnel establishment.

8. A method as claimed in claim 6, wherein the labels defining the sequence of tunnels each identify a tunnel by means of a label switched path identifier.

9. A method of routing an information packet over a label switched path from an end station to a destination via an access network and a core network comprising a plurality of nodes, the method comprising:

defining in the core network a mesh of quality of service capable tunnels interconnecting said nodes, and attaching to the packet a label stack identifying a route for a quality of service capable connection from the end station via the access network to the core network and via selected ones of said tunnels in the core network to the destination, wherein said core network nodes comprise abstract nodes each constituted by one or more real nodes.

10. A method as claimed in claim 9, wherein a route description comprises an abstract node description of the core network and an IP address of the destination.

11. A method as claimed in claim 10, wherein the labels defining the sequence of tunnels are assigned during tunnel establishment.

12. A method as claimed in claim 10, wherein the labels defining the sequence of tunnels each identify a tunnel by means of a label switched path identifier.

13. A method as claimed in claim 12, wherein a stack of four labels is used to define a sequence of four tunnels within a five-stage MPLS network.

14. A method as claimed in 13, wherein a common signalling is used to construct the access and core connections.

15. A method as claimed in 13, wherein a common signalling is used to construct the access and core connections.

16. A method as claimed in claim 15, wherein a stack of four labels is used to define a sequence of four tunnels within a five-stage MPLS network.

17. A method as claimed in claim 16, wherein the labels defining the sequence of tunnels are assigned during tunnel establishment.

18. A method as claimed in claim 16, wherein the labels defining the sequence of tunnels each identify a tunnel by means of a label switched path identifier.

19. A method of routing an information packet over a label switched path between first and second end stations in a virtual private network defined over a network arrangement incorporating an access network and an MPLS core comprising a hierarchical arrangement of first, second and third levels of routers, the method comprising attaching to the information packet a four-label stack at the edge of the network in order to achieve end-to-end connection oriented behaviour with guaranteed Quality of Service, and wherein the label allocation of a said information packet is determined from the MPLS core.

20. A method as claimed in claim 19, wherein said core network nodes comprise abstract nodes each constituted by one or more real nodes.

21. A method as claimed in claim 20, wherein a route description comprises an abstract node description of the core network and an IP address of the destination.

22. A communications multi-service network arrangement for transporting information packets from a user station to a destination, the network arrangement comprising;

a label switched core network constituted by a plurality of abstract nodes interconnected by tunnels and each comprising one or more real nodes, and an access network providing user access to the core network, wherein a route across the core network comprises a plurality of label switched path sections specified in terms of a sequence of abstract nodes, said route being identified by a label stack identifying a route for a quality of service capable connection from the end station via the access network to the core network and across the core network to a destination.

23. A communications multi-service network as claimed in claim 22, wherein the labels defining the sequence of tunnels are assigned during tunnel establishment.

24. A communications multi-service network as claimed in 23 where a common signalling is used to construct the access and core connections.

25. A communications multi-service network as claimed in claim 24, wherein the labels defining the sequence of tunnels each identify a tunnel by means of a label switched path identifier.

26. A communications multi-service network as claimed in claim 24 in which a stack of four labels is used to define a sequence of four tunnels within a five-stage MPLS network.