CLIENT/SERVER ADAPTATION SCHEME FOR COMMUNICATIONS TRAFFIC

• US 20100309924A1
• Filed: 12/19/2008
• Published: 12/09/2010
• Est. Priority Date: 12/20/2007
• Status: Active Grant

• Current Assignee: British Telecommunications PLC (BT Group PLC)
• Original Assignee: British Telecommunications PLC (BT Group PLC)
• Inventors: McGuire, Alan, Harrison, Neil
• Granted Patent: US 8,615,022 B2
• Time in Patent Office: Days
• US Class Current: 370/401
• CPC Class Codes: H04L 12/413 with random access, e.g. carrier-sense multiple-access with collision detection [CSMA-CD]
• CPC Class Codes: H04L 12/4633 Interconnection of networks using encapsulation techniques, e.g. tunneling

Abstract

A communications network provides a carrier Ethernet service without requiring the client signal to be identified by an Ethertype in a carrier Ethernet frame. A plurality of differing types of client signals can thus be encapsulated within the same carrier Ethernet service channel by using a generic framing procedure adaptation layer. The client signals are adapted for encapsulation within the carrier Ethernet frames by mapping the client signal within a generic framing procedure adaptation layer signal and then by mapping the generic framing procedure adaptation layer signal into the carrier Ethernet signal. As the client signal is identified within said generic framing procedure signal only a generic framing signal Ethertype is required. The mapping protocol enables a single Ethernet frame to carry a plurality of client signals.

Claims

1. A method of adapting a client signal for encapsulation within a carrier Ethernet signal, the method comprising:

mapping said client signal within an adaptation layer signal; and

mapping said adaptation layer signal into said carrier Ethernet signal, wherein said client signal is identified within said adaptation layer signal.

2. A method as claimed in claim 1, wherein said adaptation layer signal comprises a signal conforming to a generic framing procedure communications protocol.

3. A method as claimed in claim 1, wherein each said carrier Ethernet signal carries a plurality of different client signals.

4. A method as claimed in claim 1, wherein a frame of said client signal is mapped within a frame of said carrier Ethernet signal.

5. A method as claimed in claim 1, wherein a plurality of frames of said client signal is mapped within a frame of said carrier Ethernet signal.

6. A method as claimed in claim 1, wherein said carrier Ethernet signal conforms to a connection-oriented packet switched Ethernet communications protocol.

7. A method as claimed in claim 1, wherein mapping said adaptation layer signal into said carrier Ethernet signal comprises mapping a plurality of frames of said adaptation layer to an Ethernet frame.

8. A method as claimed in claim 7, wherein said plurality of frames of said adaptation layer each encapsulate a frame of said client signal, and said plurality of frames of said adaptation layer signal is encapsulated within said Ethernet frame.

9. A method as claimed in claim 8, wherein at least one of said plurality of frames of said adaptation layer encapsulates a client signal frame which conforms to a communications protocol different from the communications protocol of a client signal encapsulated in another one of said plurality of frames of said adaptation layer, and wherein said plurality of frames of said adaptation layer carrying the client signals conforming to differing communications protocols are encapsulated within said Ethernet frame.

10. A method as claimed in claim 1, further comprising:

determining the amount of payload required to convey a frame of said _λ

encapsulated client traffic; and

verifying the payload required is available in a frame of said carrier Ethernet signal.

11. A method as claimed in claim 1, wherein said carrier Ethernet signal comprises Jumbo Ethernet frames.

12. A method as claimed in claim 1, wherein said adaptation layer signal is identified in the carrier Ethernet signal and wherein the data structure of said adaptation layer signal indicates the position and length of the client data in the bit stream comprising the carrier Ethernet signal.

13. A method as claimed in claim 1, wherein said adaptation layer signal is identified in each frame of the carrier Ethernet signal by an Ethertype value provided in the Ethertype field of the frame header.

19. Apparatus comprising means arranged to implement one or more steps in any of method claim 1.

14. A method of de-encapsulating a client signal encapsulated within a carrier Ethernet frame, the method comprising:

receiving the carrier Ethernet signal;

determining an adaptation layer signal is encapsulated within said carrier Ethernet signal;

processing said adaptation signal to identify said client signal within said adaptation signal, and de-encapsulating said client signal from said adaptation layer signal.

15. A method as claimed in claim 14, wherein each received said Ethernet frame header is processed to determine if its payload comprises adaptation layer signal data by identifying if the Ethernet frame header contains an Ethertype indicating the Ethernet payload area comprises data conforming to the communications protocol of said adaptation layer.

16. A method as claimed in claim 14, wherein the Ethernet payload area is processed to determine from said adaptation layer data the position and length of one or more client signals encapsulated within the Ethernet payload area in order to de-encapsulate the client signal.

17. A method as claimed in claim 16, wherein a plurality of client signals are encapsulated within the payload of each carrier Ethernet frame and wherein the method further comprises processing the Ethernet payload area until all of the client signals are de-encapsulated.

18. A method of de-encapsulating a client signal encapsulated within a carrier Ethernet frame, the method comprising:

de-encapsulating said adaptation layer signal from said carrier Ethernet signal to extract a plurality of adaptation layer frames;

processing each said de-encapsulated frame of said adaptation layer signal to identify a frame of said client signal within said adaptation layer signal, and de-encapsulating each said frame of said client signal from said adaptation layer signal.

20. Apparatus arranged to adapt a client signal for encapsulation within a carrier Ethernet signal, the apparatus comprising:

a first communications protocol encapsulation means arranged to encapsulate said client signal within a generic framing procedure adaptation layer signal;

a second communications protocol encapsulation means arranged to encapsulate said generic framing procedure adaptation layer signal into said carrier Ethernet signal, whereby said client signal is identified within said generic framing procedure signal.

22. Apparatus as claimed in claim 20, wherein each received Ethernet frame header is processed to determine if an Ethertype indicating the Ethernet payload area comprises generic framing procedure communications data is present to determine if a generic framing procedure adaptation layer signal is encapsulated within said carrier Ethernet frame.

23. Apparatus as claimed in claim 20, wherein said processing means is arranged to process the Ethernet payload area to determine from said generic framing procedure data the position and length of the client signal encapsulated within the Ethernet payload area in order to de-encapsulate the client signal.

21. Apparatus arranged to de-encapsulate a client signal encapsulated within a carrier Ethernet frame, the apparatus comprising:

a receiver arranged to receive the carrier Ethernet signal; and

signal processing means arranged to determine if a generic framing procedure adaptation layer signal is encapsulated within said carrier Ethernet signal;

signal processing means arranged to process said generic framing procedure signal to identify said client signal within said generic framing procedure signal, and means to de-encapsulate said client signal from said generic framing procedure adaptation layer signal.

24. Apparatus arranged to de-encapsulate the client signal from within a carrier Ethernet frame, the apparatus comprising:

means to de-encapsulate said generic framing procedure adaptation layer signal from said carrier Ethernet signal to extract a plurality of generic framing procedure frames;

means to process each said de-encapsulated frame of said generic framing procedure signal to identify a frame of said client signal within said generic framing procedure signal, and means to de-encapsulate each said frame of said client signal from said generic framing procedure adaptation layer signal.