Method and apparatus for internetworking ethernet and mpls networks

Abstract

MPLS networks offering PW or VPLS services may be interconnected with Ethernet networks implemented according to 802.1ah or 802.1Qay. The MPLS network may be a core and offer services to the Ethernet access networks, or vise-versa. Additionally, a mixture of different types of access networks may be interconnected by an MPLS core or an Ethernet core. Both network interworking and service interworking are provided. OAM fault detection may be implemented via maintenance entities extending across the network or end to end depending on the combination of networks and services offered by the networks.

What is claimed is: 
     
         1 . A method of forwarding frames between Multi-Protocol Label Switching (MPLS) networks interconnected by an intervening Ethernet network, the intervening Ethernet network implementing an IEEE 802.1 Ethernet protocol, including a plurality of Ethernet network elements interconnected between the MPLS networks and implementing a control plane separate from a control plane of the MPLS networks, the method comprising:
 establishing a plurality of paths, using the control plane of the intervening Ethernet network to interconnect pairs of the MPLS networks;   mapping Ethernet encapsulated Label Switched Path (LSP) frames received from one of the MPLS networks at an ingress to the Ethernet network onto the paths at the ingress to the Ethernet network according to classification identifiers associated with the Ethernet encapsulated LSP frames; and   at MPLS access switches of each of the MPLS networks coupled to the intervening Ethernet network, establishing a pseudo-wire service between the MPLS access switches across the intervening Ethernet network, such that native service frames of an MPLS network are carried transparently over the pseudo-wire service.   
     
     
         2 . The method of  claim 1 , wherein the intervening Ethernet network is a Provider Backbone Trunking (PBT) network, the paths are PBT trunks, and the classification identifiers are physical ports at the ingress to the Ethernet network. 
     
     
         3 . The method of  claim 1 , wherein the intervening Ethernet network is a Provider Backbone Trunking (PBT) network, the paths are PBT trunks, and the classification identifiers are Virtual Local Area Network Identifiers (VLAN IDs). 
     
     
         4 . The method of  claim 1 , wherein the intervening Ethernet network is a Provider Backbone Bridging (PBB) network, the paths are PBB tunnels, and the classification identifiers are physical ports at the ingress to the intervening Ethernet network. 
     
     
         5 . The method of  claim 1 , wherein the intervening Ethernet network is a Provider Backbone Bridging (PBB) network, the paths are PBB tunnels, and the classification identifiers are Virtual Local Area Network Identifiers (VLAN IDs). 
     
     
         6 . The method of  claim 1 , wherein Label Switched Path (LSP) EXP bits from the MPLS network are mapped to p-bits of B-Tags in the intervening Ethernet network at the ingress. 
     
     
         7 . The method of  claim 1 , wherein the Ethernet encapsulated LSP frames are Pseudowire (PW) encapsulated. 
     
     
         8 . The method of  claim 1 , wherein the classification identifiers are combinations of Virtual Local Area Network Identifiers (VLAN IDs) and destination Media Access Control (MAC) addresses associated with Ethernet encapsulated LSP frames from the MPLS networks. 
     
     
         9 . The method of  claim 1 , wherein the intervening Ethernet network monitors continuity of paths in the intervening Ethernet network, and upon detecting loss of continuity in the paths, notifies the MPLS networks via an Alarm Indication Signal (AIS) for each classification identifier affected by the loss of continuity. 
     
     
         10 . A method of forwarding frames between Ethernet networks interconnected by an intervening Multi-Protocol Label Switching (MPLS) network, each of the Ethernet networks including a plurality of Ethernet network elements, and the Ethernet networks being implemented as a single Provider Backbone Bridging-Traffic Engineering (PBB-TE) domain having a common control plane and having traffic engineered paths extending across the intervening MPLS network, and the intervening MPLS network including a plurality of MPLS network elements, the method comprising:
 establishing a plurality of MPLS network Paths to interconnect pairs of the Ethernet networks;   mapping Ethernet frames received from one of the Ethernet networks at an ingress to the intervening MPLS network to the Paths to be forwarded across the intervening MPLS network according to classification identifiers associated with the Ethernet frames; and   in each Ethernet network, using a unique set of Provider Virtual Local Area Network Identifiers (B-VIDs) for traffic engineered paths connecting to each other Ethernet network to identify a destination Ethernet network across the intervening MPLS network, an Ethernet network of the interconnected pairs of Ethernet networks coupled to the intervening MPLS network having an Ethernet access switch configured to hand off Ethernet frames to a metro access switch to be carried transparently over an E-line service over the intervening MPLS network.   
     
     
         11 . The method of  claim 10 , wherein a Pseudowire is constructed on the intervening MPLS network to provide a traffic profile which is the same as a traffic profile associated with the traffic engineered path within the Ethernet networks. 
     
     
         12 . The method of  claim 10 , wherein the intervening MPLS network implements Operation, Administration and Maintenance Management Entities (OAM MEs) on the Pseudowires (Pws), and wherein the intervening MPLS network notifies the Ethernet networks of a failure on a PW via an Alarm Indication Signal (AIS) on the traffic engineered path. 
     
     
         13 . A method of forwarding frames between Ethernet networks interconnected by an intervening Multi-Protocol Label Switching (MPLS) network, each of the Ethernet networks including a plurality of Ethernet network elements and being implemented as multiple independent administrative domains, the intervening MPLS network including a plurality of MPLS network elements, the method comprising:
 establishing a plurality of MPLS network Paths to interconnect pairs of the Ethernet networks;   mapping Ethernet frames received from one of the Ethernet networks at an ingress to the intervening MPLS network to the Paths to be forwarded across the intervening MPLS network according to classification identifiers associated with the Ethernet frames;   configuring traffic engineered paths in at least one Ethernet network for each of the independent Ethernet administrative domains to connect with traffic engineered paths extending across the intervening MPLS network; and   in each Ethernet network, using a unique set of Provider Virtual Local Area Network Identifiers (VLAN IDs) for traffic engineered paths connecting to each other Ethernet network to identify a destination Ethernet network across the intervening MPLS network, each Ethernet network of the pair of Ethernet networks interconnected by the intervening MPLS core network having an access switch configured to hand off native service frames to a PBB/PBT access switch to be carried transparently over a Pseudowire service across the intervening MPLS core network.   
     
     
         14 . The method of  claim 13 , wherein the Ethernet networks support VLAN ID translation in both directions to enable different VLAN IDs to be used within the Ethernet networks than are used in connection with traffic that is to be passed across the intervening MPLS network. 
     
     
         15 . The method of  claim 13 , wherein an Ethernet network element on an edge between one of the Ethernet networks and the MPLS network maintains a mapping of traffic engineered paths in the Ethernet network and across the intervening MPLS network, on a per-service-instance (per-I-SID) basis. 
     
     
         16 . The method of  claim 15 , wherein the Ethernet network element implements I-SID translation to enable different I-SID values to be used in the Ethernet network and the intervening MPLS network. 
     
     
         17 . The method of  claim 13 , wherein Operation, Administration and Maintenance Management Entities (OAM MEs) are implemented on the traffic engineered paths across the intervening MPLS network.