DIFFERENTIAL FORWARDING IN ADDRESS-BASED CARRIER NETWORKS

• US 20080310417A1
• Filed: 08/22/2008
• Published: 12/18/2008
• Est. Priority Date: 04/06/2004
• Status: Active Grant

• Current Assignee: RPX Clearinghouse LLC (RPX Corporation)
• Original Assignee: Nortel Networks Limited (Nortel Networks Corporation)
• Inventors: Bragg, Nigel, Ashwood Smith, Peter, Allan, David, Brueckheimer, Simon, Parry, Simon, Friskney, Robert
• Granted Patent: US 8,194,668 B2
• Time in Patent Office: Days
• US Class Current: 370/392
• CPC Class Codes: H04L 12/4645 Details on frame tagging routing of packets H04L45/00; support for virtual LAN H04L49/354
• CPC Class Codes: H04L 41/0823 characterised by the purposes of a change of settings, e.g. optimising configuration for enhancing reliability for optimising operational conditions of wireless networks H04W24/02
• 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 45/16 Multipoint routing
• CPC Class Codes: H04L 45/54 Organization of routing tables
• CPC Class Codes: H04L 45/64 using an overlay routing layer
• CPC Class Codes: H04L 45/66 Layer 2 routing, e.g. in Ethernet based MAN's
• CPC Class Codes: H04L 45/72 Routing based on the source address
• CPC Class Codes: H04L 49/205 Quality of Service based
• CPC Class Codes: H04L 49/253 using establishment or release of connections between ports
• CPC Class Codes: H04L 49/254 Centralised controller, i.e. arbitration or scheduling
• CPC Class Codes: H04L 49/351 for local area network [LAN], e.g. Ethernet switches
• CPC Class Codes: H04L 49/354 for supporting virtual local area networks [VLAN]

Abstract

The invention relates to enabling differential forwarding in address-based carrier networks such as Ethernet networks. There is described a method of and connection controller for establishing connections (76, 77) in a frame-based communications network comprising nodes (71-75 and 78) such as Ethernet switches. The connections are established by configuring, in various of the nodes, mappings for forwarding data frames, such as Ethernet frames. The mappings are from a combination of a) a destination (or source) address corresponding to a destination (or source) node (73) of the connection and b) an identifier, such as a VLAN tag. The mappings are to selected output ports of the various nodes. By using the combination of destination (or source) address AND identifier, the mappings enable data frames belonging to different connections (76, 77) to be forwarded differentially (ie forwarded on different output ports) at a node (75) despite the different connections having the same destination node. This enables flexibility in routing connections and the ability to perform traffic engineering.

Claims

1. A method of identifying data packets to be transported through a connection in an Ethernet-based carrier network providing communications services to customers, the method comprising the steps of:

storing association data associating;

a customer attachment interface terminating a customer service, and

a connection in the network, the connection being defined by a combination of a MAC address and an identifier;

identifying data packets as corresponding to the customer service; and

using the association data to identify the data packets as being for transport through the connection.

2. A method according to claim 1, wherein the step of identifying data packets as corresponding to the customer service comprises receiving the data packets at a port of a switch of the network, the port being associated with the customer attachment interface.

3. A method according to claim 1, comprising:

forwarding the data packets over the connection.

4. A method according to claim 1, comprising:

encapsulating the data packets prior to forwarding the data packets over the connection.

5. A method according to claim 3, comprising

applying the identifier to the data packets prior to forwarding the data packets over at least part of the connection.

6. A method according to claim 1, wherein the association data comprises an association between a specific physical customer-facing port of a switch of the network, an encapsulation function, an encapsulation service identifier and the connection.

7. A method according to claim 1, wherein the association data comprises an association between a specific physical customer-facing port, a customer VLAN tag, an encapsulation function, an encapsulation service identifier, a policer set to identify an acceptable quantity of traffic and the connection.

8. A method according to claim 1, wherein the association data comprises a filter established by a layer 3-layer 7 switch identifying a SIP-signalled VoIP flow to identify all of the packets of the flow and the connection.

9. A method according to claim 1, wherein the association data comprises an association between an encapsulation function, an encapsulation service identifier, a port of a virtual customer-address-space Ethernet switch instance and the connection,

10. A method according to claim 1, wherein the association data comprises an association between a physical port of a node of the network, a VLAN tag application function at that node and the connection.

22. A method according to claim 1, wherein the first network address is a destination address.

23. A method according to claim 1, wherein the first network address is a source address.

24. A method according to claim 1, wherein the identifier is one selected from the group consisting of:

a VLAN tag or part thereof;

an IEEE 802.1Q field or part thereof;

an MPLS label or part thereof;

a DiffServ codepoint (DSCP) or part thereof; and

an IPv6 flow identifier or part thereof.

25. A method according to claim 1, wherein the data packets are ones selected from the group consisting of:

MAC frames transported over MAC frames and Pseudo-Wire frames transported over MAC frames.

26. A method according to claim 1, wherein broadcast on unknown destination address functionality is disabled on Ethernet switches of the network.

27. A method according to claim 1, wherein broadcast on unknown destination address functionality is rate limited on Ethernet switches of the network.

28. A method according to claim 1, wherein the network is at least partially meshed.

29. A method according to claim 1, wherein the customer attachment interface is identified using a service instance identifier.

11. A node for use in an Ethernet-based carrier network providing communications services to customers and arranged to identify data packets to be transported through a connection in the network, the node comprising:

a data store storing association data associating;

a customer attachment interface terminating a customer service, and

a connection in the network, the connection being defined by a combination of a MAC address and an identifier;

a processor arranged to identify data packets as corresponding to the customer service; and

a processor arranged to identify the data packets as being for transport through the connection using the association data.

12. A node according to claim 11, wherein the processor arranged to identify packets as corresponding to the customer service is arranged to identify the packets on the basis of the data packets being received at a port of a switch of the network, the port being associated with the customer attachment interface.

13. A node according to claim 11, wherein the association data comprises an association between a specific physical customer-facing port of a switch of the network, an encapsulation function, an encapsulation service identifier and the connection.

14. A node according to claim 11, wherein the association data comprises an association between a specific physical customer-facing port, a customer VLAN tag, an encapsulation function, an encapsulation service identifier, a policer set to identify an acceptable quantity of traffic and the connection.

15. A node according to claim 11, wherein the association data comprises a filter established by a layer 3-layer 7 switch identifying a SIP-signalled VoIP flow to identify all of the packets of the flow and the connection.

16. A node according to claim 11, wherein the association data comprises an association between an encapsulation function, an encapsulation service identifier, a port of a virtual customer-address-space Ethernet switch instance and the connection,

17. A node according to claim 11, wherein the association data comprises an association between a physical port of a node of the network, a VLAN tag application function at that node and the connection.

18. A node according to claim 11, the node being an Ethernet switch of the network having a port associated with the customer attachment interface.

19. A node according to claim 18 comprising:

an output for forwarding the data packets over the connection.

20. A node according to claim 19 comprising:

a processor arranged to apply the identifier to the data packets prior to forwarding the data packets over the connection.

21. A node according to claim 19, comprising:

a processor arranged to encapsulate the data packets prior to their being forwarded over the connection.

30. A node according to claim 11, wherein the first network address is a destination address.

31. A node according to claim 11, wherein the first network address is a source address.

32. A node according to claim 11, wherein the identifier is one selected from the group consisting of:

a VLAN tag or part thereof;

an IEEE 802.1Q field or part thereof;

an MPLS label or part thereof;

a DiffServ codepoint (DSCP) or part thereof; and

an IPv6 flow identifier or part thereof.

33. A node according to claim 11, wherein the data packets are ones selected from the group consisting of:

MAC frames transported over MAC frames and Pseudo-Wire frames transported over MAC frames.

34. A node according to claim 11, wherein broadcast on unknown destination address functionality is disabled on Ethernet switches of the network.

35. A node according to claim 11, wherein broadcast on unknown destination address functionality is rate limited on Ethernet switches of the network.

36. A node according to claim 11, wherein the network is at least partially meshed.

37. A node according to claim 11, wherein the customer attachment interface is identified using a service instance identifier.