Differential forwarding in address-based carrier networks

Patent metadata

Field	Value
Publication number	US-9356862-B2
Application number	US-201414478001-A
Country	US
Kind code	B2
Filing date	Sep 5, 2014
Priority date	Apr 6, 2004
Publication date	May 31, 2016
Grant date	May 31, 2016

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.

First claim

The invention claimed is:

1. A carrier Ethernet network configured for providing a Virtual Private LAN Service (VPLS), the carrier Ethernet network comprising:
a first node configured:
to receive a frame from a customer, the frame having a first customer MAC address as a customer source MAC address and a second customer MAC address as a customer destination MAC address;
to encapsulate the frame for transport across the carrier Ethernet network with a VLAN identifier, an encapsulating source MAC address and an encapsulating destination MAC address, the encapsulating source MAC address being a MAC address of the first node; and
to forward the encapsulated frame across the carrier Ethernet network based on the combination of the VLAN identifier and the encapsulating destination MAC address; and

a second node configured:
to receive the encapsulated frame;
to configure a mapping between the customer source MAC address of the frame and the MAC address of the first node, the MAC address of the first node being learned from the encapsulating source MAC address of the frame; and
to forward the frame to the customer based on the customer destination MAC address.

2. The network of claim 1 , wherein:
the first node is configured:
to store association data associating a service instance identifier, a customer attachment interface terminating a customer service and a combination of a VLAN identifier and the encapsulating destination MAC address; and
to further encapsulate the frame for transport across the carrier Ethernet network by including the service instance identifier in the encapsulated frame; and

the second node is configured to forward the frame to the customer identified by the service instance identifier in the encapsulated frame.

3. The network of claim 2 , configured to associate a first service instance identifier with a first customer and a second service instance identifier with a second customer, wherein:
the first node is configured:
to encapsulate a first frame from a first customer attachment interface associated with the first customer with a VLAN identifier, an encapsulating destination MAC address and the first service instance identifier;
to encapsulate a second frame from a second customer attachment interface associated with the second customer with the VLAN identifier, the encapsulating destination MAC address and the second service instance identifier; and
to forward the encapsulated first and second frames across the carrier Ethernet network based on the combination of the VLAN identifier and the encapsulating destination MAC address; and

the second node is configured:
to receive and decapsulate the encapsulated first and second frames; and
to forward the decapsulated first and second frames to the first and second customers respectively based on the first and second service instance identifiers received in the encapsulated first and second frames respectively.

4. The network of claim 1 , wherein the second node is configured:
to receive a frame from the customer, the frame having the first customer MAC address as a customer destination MAC address; and
to use the mapping between the first customer MAC address and the MAC address of the first node and the VLAN identifier to encapsulate the frame for transport across the carrier Ethernet network with the VLAN identifier, an encapsulating source MAC address and an encapsulating destination MAC address, the encapsulating source MAC address being the MAC address of the second node.

5. The network of claim 4 , wherein the mapping between the customer source MAC address of the frame and the MAC address of the first node comprises a mapping between the customer source MAC address of the frame and a combination of the MAC address of the first node and the VLAN identifier.

6. The network of claim 1 , further configured to establish a connection through the carrier Ethernet network by, without Ethernet unknown destination address forwarding and source address learning:
determining a path for the connection through the Ethernet carrier network;
selecting a VLAN for association with the connection, the VLAN having a VLAN identifier;
selecting an encapsulating MAC address for association with the connection; and
configuring, in at least one intermediate node along the connection, a respective mapping for use by the intermediate node in forwarding data frames carrying the VLAN identifier of the selected VLAN and the selected encapsulating MAC address as a destination address, each respective mapping associating a combination comprising the selected encapsulating MAC address and the VLAN identifier with a selected output port of the intermediate node;
wherein forwarding the encapsulated frame based on the combination of the VLAN identifier and the encapsulating MAC address comprises forwarding the frame on the established connection.

7. The network of claim 1 , wherein the mapping between the customer source MAC address of the frame and the MAC address of the first node comprises a mapping between the customer source MAC address of the frame and a combination of the MAC address of the first node and the VLAN identifier.

8. A carrier Ethernet network configured for forwarding customer data frames, the network comprising:
at least one connection controller configured to establish a connection through the carrier Ethernet network by, without Ethernet unknown destination address forwarding and source address learning:
determining a path for the connection through the Ethernet carrier network;
selecting a VLAN for association with the connection, the VLAN having a VLAN identifier;
selecting an Ethernet MAC address for association with the connection; and
forwarding packets associated with the selected VLAN and the selected Ethernet MAC address at nodes on the path based on the combination of the VLAN identifier and the Ethernet MAC address without changing the VLAN identifier; and

a node identified by the Ethernet MAC address selected for a particular connection configured:
to receive a customer data frame over the particular connection, the customer data frame having a particular customer source address;
in response to receipt of the customer data frame, to configure a mapping between the particular customer source address and a source Ethernet MAC address of the received frame;
to receive further customer data frames at the node, the further customer data frames having a customer destination address equal to the particular customer source address; and
to forward the further customer data frames over a connection associated with the Ethernet MAC address to which the customer destination address is mapped by the mapping.

9. The network of claim 8 , configured:
to associate at least one respective service instance identifier with each of a plurality of customers;
to associate one of the respective service instance identifiers with each data frame associated with a customer;
to forward customer data frames associated with different customers over the particular connection based on the VLAN identifier and the Ethernet MAC address of the particular connection; and
at the node identified by the Ethernet MAC address, to forward the customer data frames to appropriate customers based on the respective service instance identifiers in each data frame.

10. The network of claim 9 , wherein the plurality of connections comprises establishing a mesh of connections in the carrier Ethernet network.

11. The network of claim 9 , configured:
to configure mappings of customer destination addresses to respective connections at nodes of the carrier Ethernet network; and
to forward customer data frames over re

Assignees

• Rpx Clearinghouse Llc

Inventors

• Friskney Robert
• Bragg Nigel
• Parry Simon
• Ashwood-Smith Peter
• Allan David
• Brueckheimer Simon

Classifications

• H04L49/205

  Quality of Service based · CPC title

• H04L45/66

  Layer 2 routing, e.g. in Ethernet based MAN's · CPC title

• H04L45/74 Primary

  Address processing for routing · CPC title

• H04L12/4641

  Virtual LANs, VLANs, e.g. virtual private networks [VPN] (LAN interconnection over a bridge based backbone H04L12/462; encapsulation techniques H04L12/4633; routing of packets H04L45/00; packet switches H04L49/00; virtual private networks for security H04L63/0272) · CPC title

• H04L45/54

  Organization of routing tables · CPC title