Evolution of ethernet networks

Abstract

An Ethernet network comprises nodes which support a plurality of different forwarding modes. A range of VLAN Identifiers (VIDs) are allocated to each of the forwarding modes. Connections are configured between a source node and a destination node of the network using different forwarding modes. Packets carrying data traffic are sent to the destination node by selectively setting a VID in a packet to a first value, to transfer a packet via a first connection and a first forwarding mode, and a second value to transfer a packet via the second connection and the second forwarding mode. Packets received from both of the connections and sent on to an end user. VLAN Identifiers can be allocated to different releases of functionality at nodes (e.g. software releases) such that packets are forwarded via a set of nodes supporting a first release, or via a set of nodes supporting a second release.

What is claimed is: 
     
         1 . An Ethernet network comprising a plurality of nodes and a plurality of communication links interconnecting the nodes, the Ethernet network being configured:
 to use a PBB forwarding mode between a source node and a destination node of the network for a first VLAN identified by a first VLAN identifier (VID) value;   to use a PLSB forwarding mode between the source node and the destination node for a second VLAN identified by a second VID value; and   to send packets carrying data traffic from the source node to the destination node by, at the source node:
 selectively setting a VID in a packet to the first value identifying the first VLAN, to transfer the packet via the first VLAN using the PBB forwarding mode; and 
 selectively setting a VID in a packet to the second value identifying the second VLAN to transfer the packet via the second VLAN using the PLSB forwarding mode. 
   
     
     
         2 . The Ethernet network of  claim 1 , wherein the Ethernet network is further configured:
 to identify data traffic flows with service identifiers; and   to store a look-up table relating a service identifier to a VID value for one of the first VLAN and the second VLAN.   
     
     
         3 . The Ethernet network of  claim 2 , wherein at least one of the source node and the destination node has a plurality of MAC addresses, and at least one of the source node and the destination node is configured:
 to store a look-up table relating a service identifier to a combination of a first MAC address and a first VID value for the first VLAN; and   when sending a packet carrying traffic to the destination node of the network via the first VLAN, to include the first VID and the first MAC address in the packet.   
     
     
         4 . The Ethernet network of  claim 2 , wherein at least one of the source node and the destination node has a plurality of MAC addresses, and at least one of the source node and the destination node is configured:
 to store a look-up table relating a service identifier to a combination of a second MAC address and a second VID value for the second VLAN; and   when sending a packet carrying traffic to the destination node of the network via the first VLAN, to include the second VID and the second MAC address in the packet.   
     
     
         5 . The Ethernet network of  claim 1 , wherein the Ethernet network is further configured to test operation of the second VLAN by sending a test packet before sending packets carrying data traffic over the second VLAN. 
     
     
         6 . The Ethernet network of  claim 1 , wherein the plurality of nodes of the network are configured:
 to learn the topology of the network by exchanging link state protocol packets; and   to populate a forwarding table before forwarding packets carrying data traffic over the second VLAN.   
     
     
         7 . The Ethernet network of  claim 1 , wherein the Ethernet network is further configured to send packets via the first and second VLANs, each packet carrying a data payload such that a packet sent via one of the VLANs carries a data payload which is contiguous to a data payload carried in a packet sent via the other of the VLANs. 
     
     
         8 . The Ethernet network of  claim 1 , wherein the destination node is configured to accept packets from the first VLAN and the second VLAN in an order in which they arrive at the destination node. 
     
     
         9 . The Ethernet network of  claim 1 , wherein:
 a first set of VIDs is allocated to the PBB forwarding mode; and   a second set of VIDs is allocated to the PLSB forwarding mode.   
     
     
         10 . The Ethernet network of  claim 9 , further comprising a network management entity coupled to participating nodes of the plurality of nodes of the Ethernet network and configured to allocate the first and second sets of VIDs across all participating nodes of the plurality of nodes of the Ethernet network. 
     
     
         11 . The Ethernet network of  claim 9 , comprising a control plane coupled to participating nodes of the plurality of nodes of the network and configured to allocate the first and second sets of VIDs across all participating nodes of the plurality of nodes of the network. 
     
     
         12 . An Ethernet network comprising a plurality of nodes and a plurality of communication links interconnecting the nodes, the plurality of nodes comprising:
 a first set of nodes comprising a source node, a destination node and at least one intermediate node between the source node and the destination node, the first set of nodes being configured with a first release of functionality to implement a first forwarding mode in a first VLAN, the first VLAN being allocated a VLAN Identifier (VID) having a first value; and   a second set of nodes comprising the source node, the destination node and at least one intermediate node between the source node and the destination node, at least one node of the second set of nodes having installed therein a second release of functionality implementing a second packet forwarding mode, the second forwarding mode being configured between the source node and the destination node via the second set of nodes in a second VLAN, the second VLAN being allocated a VLAN Identifier (VID) having a second value.   
     
     
         13 . The Ethernet network of  claim 12 , wherein the first set of nodes is the same as the second set of nodes. 
     
     
         14 . The Ethernet network of  claim 12 , wherein each release of functionality is allocated a different set of VIDs. 
     
     
         15 . The Ethernet network of  claim 12 , wherein the first forwarding mode is the same as the second forwarding mode. 
     
     
         16 . The Ethernet network of  claim 12 , further comprising a management entity, the management entity being configured to install the second release of functionality in all nodes of the second set of nodes. 
     
     
         17 . The Ethernet network of  claim 12 , wherein the source node is configured to send packets carrying data traffic to the destination node by selectively:
 setting a VID in a packet to the first value, to transfer the packet using the first forwarding mode via the first set of nodes, and   setting a VID in a packet to the second value to transfer the packet using the second forwarding mode via the second set of nodes.   
     
     
         18 . The Ethernet network of  claim 17 , wherein the source node is further configured to test operation of the second forwarding mode by sending a test packet carrying a VID set to the second value before sending packets carrying data traffic in the second VLAN. 
     
     
         19 . The Ethernet network of  claim 12 , wherein at least one of the first release of functionality and the second release of functionality comprises Provider Backbone Bridging (PBB) functionality. 
     
     
         20 . The Ethernet network of  claim 12 , wherein at least one of the first release of functionality and the second release of functionality comprises Provider Link State Bridging (PLSB) functionality.