Multi-protocol support over Ethernet packet-switched networks
Described are methods and communications network for carrying pseudowires over packet-switched network. A communication network includes a packet-switched network (PSN), a first provider edge (PE) device in communication with a second PE device through the PSN, and a pseudowire (PW) established between the PE devices for emulating a service across the PSN. The PW has a Virtual Circuit Connection Verification (VCCV) control channel that carries an Ethernet Operations, Administration, and Maintenance (OAM) message. In some embodiments, various data plane encapsulation formats enable a PW to emulate an Ethernet or a non-Ethernet service over an Ethernet PSN. Each encapsulation format includes an Ethernet tunnel header and a PW header that encapsulates an Ethernet or non-Ethernet payload.
1. A communications network comprising:
an Ethernet packet-switched network (PSN);
a first provider edge (PE) device in communication with a second PE device through the Ethernet PSN;
a pseudowire (PW) established between the PE devices for emulating a service across the Ethernet PSN, each packet of the service having a frame format with an Ethernet tunnel header and a PW header that encapsulates a payload; and
a Multi-Protocol Label Switching (MPLS) network in communication with the Ethernet PSN, wherein the PW extends through the MPLS network and the Ethernet PSN, and wherein each packet is forwarded through the MPLS network after removing the Ethernet tunnel header from the packet and adding a Multi-Protocol Label Switching (MPLS) tunnel header to the packet.
2. The communications network of claim 1 , wherein the service is a non-Ethernet service and the payload is a non-Ethernet payload.
3. The communications network of claim 1 , wherein the service is an Ethernet service and the payload is an Ethernet payload.
4. The communications network of claim 1 , wherein the payload is normalized by Martini encapsulation.
5. The communications network of claim 1 , wherein the PW header of the frame format includes an Ethertype field used to signify a type of service of the non-Ethernet payload.
6. The communications network of claim 1 , wherein the PW header includes a service identifier (I-SID) for identifying a particular flow of the non-Ethernet service.
7. The communications network of claim 1 , wherein the Ethernet tunnel header of the frame format includes an Ethertype signifying Martini encapsulation of the PW.
8. The communications network of claim 1 , wherein the PW header of the frame format includes a VC (Virtual Circuit) label used to identify a particular flow of the service.
9. The communications network of claim 1 , wherein the Ethernet PSN is configured to provide Provider Backbone Transport (PBT).
10. The communications network of claim 1 , wherein the Ethernet PSN is configured to provide Provider Backbone Bridging (PBB).
11. The communications network of claim 1 , wherein the Ethernet PSN adds an Ethernet 802.1ah tag to each packet of the service to forward the packet to the MPLS network.
12. A method of emulating a service across an Ethernet packet-switched network (PSN), the method comprising:
configuring the Ethernet PSN to provide Provider Backbone Bridging (PBB);
establishing a pseudowire (PW) between a first provider edge (PE) device and a second PE device on the Ethernet PSN;
encapsulating a payload of packets of the service in a PW header and in an Ethernet tunnel header; and
receiving a packet of the service at the first PE device for forwarding to the second PE device through the Ethernet PSN over the PW; and
forwarding the packet through a Multi-Protocol Label Switching (MPLS) network after removing the Ethernet tunnel header from the packet and adding a MPLS tunnel header to the packet.
13. The method of claim 12 , wherein the service is a non-Ethernet service and the payload is non-Ethernet payload.
14. The method of claim 12 , wherein the service is an Ethernet service and the payload is Ethernet payload.
15. The method of claim 12 , further comprising the step of normalizing the payload by Martini encapsulation.
16. The method of claim 12 , further comprising the step of signifying a type of service of the payload in an Ethertype field in the PW header.
17. The method of claim 12 , further comprising the step of identifying a particular flow of the service with a service identifier (I-SID) in the PW header.
18. The method of claim 12 , further comprising the step of signifying, in the Ethernet tunnel header, Martini encapsulation of the PW.
19. The method of claim 12 , further comprising the step of identifying a particular flow of the service with a VC (Virtual Circuit) label in the PW header.
20. The method of claim 12 , further comprising the step of configuring the Ethernet PSN to provide Provider Backbone Transport (PBT).
21. The method of claim 12 , comprising adding an Ethernet 802.1ah tag to each packet of the service for forwarding the packet to the MPLS network.
22. The method of claim 12 , further comprising the steps of removing the MPLS tunnel header from the packet, and adding the Ethernet tunnel header to the packet for forwarding through the Ethernet PSN.