Data forwarding method and apparatus

• US 20020196802A1
• Filed: 06/14/2002
• Published: 12/26/2002
• Est. Priority Date: 02/26/1998
• Status: Active Grant

• Current Assignee: RPX Clearinghouse LLC (RPX Corporation)
• Original Assignee: Joshua Sakov, Mohan Dattatreva, Vasant Sahay
• Inventors: Dattatreva, Mohan, Sakov, Joshua, Sahay, Vasant
• Granted Patent: US 7,411,916 B2
• Time in Patent Office: Days
• US Class Current: 370/432
• CPC Class Codes: H04L 12/2856 Access arrangements, e.g. Internet access asynchronous transfer mode networks H04L12/5601; broadband local area networks H04L12/2801; optical access or distribution networks H04Q11/0067; access to open networks H04L12/5691; digital subscriber line end-user equipment and bit-level processing of data on a PSTN-based network H04M11/00; home network gateways H04L12/2834; wireless access networks H04W
• CPC Class Codes: H04L 12/2859 Point-to-point connection between the data network and the subscribers encapsulation H04L12/4633; virtual LANs H04L12/4641; routing of packets H04L45/00
• CPC Class Codes: H04L 12/2881 IP/Ethernet DSLAM
• CPC Class Codes: H04L 61/00 Network arrangements, protocols or services for addressing or naming
• CPC Class Codes: H04L 61/10 of different types

Abstract

A method and an apparatus that reduce the burden on routers by removing the aggregation and physical Wide Area Network (WAN) interface functions from the router are provided. The aggregation and physical Wide Area Network interface transparently forwards traffic and routing information to and from the WAN without becoming a router. The disclosed forwarding technique and apparatus is applicable to IP protocol as well as other protocols. As provided, the routing device is connected to a forwarding device via the Local Area Network (LAN) and the IP Multiplexer forwards data packets to one or more physical WAN links.

Claims

1. A data forwarder to forward data on a computer network, including:

at least one input interface;

a plurality of output interfaces, each output interface having an actual address;

means for matching the actual addresses of the output interfaces with virtual addresses of the output interfaces, the virtual addresses actually associated with the data forwarder but only virtually associated with the output interfaces;

means for receiving data over the input interface, the received data including information content and also having one of the virtual addresses included therein; and

means for matching the virtual address in the data to one of the output interfaces, using the matching means, and for transmitting the information content of the data over the output interface to which the address in the data has been matched by the matching means.

2. The data forwarder of claim 1, wherein the input interfaces is an interface to a local area network (LAN), and the data forwarder is configured to receive all data transmitted over the LAN.

3. The data forwarder of claim 2, wherein the LAN is operating under an Ethernet protocol, and the data forwarder is configured to receive all data transmitted over the LAN by being configured in a promiscuous mode.

4. The data forwarder of claim 1, wherein the virtual addresses are MAC addresses.

5. The data forwarder of claim 2, wherein the output interfaces are wide area network (WAN) interfaces.

6. The data forwarder of claim 4, wherein at least some of the WAN interfaces are connected to network routers.

7. The data forwarder of claim 1, wherein the matching means includes

a table of indications of the output interfaces, the table being indexable by the virtual addresses in the received data.

8. The data forwarder of claim 7, wherein the matching means further includes:

means for determining, from a table and using at least a portion of the virtual address in the input data, the indication of the output interface that corresponds to the input address in the input data.

9. The data forwarder of claim 8, wherein the indications of the output interface are stored in the table as a packed group.

10. The data forwarder of claim 8, wherein the output interface indication determining means includes means indexing into the table using a portion of the virtual address in the input data as an index.

11. The data forwarder of claim 1, and further comprising:

means for receiving a request, via one of the input interfaces, for an actual input address corresponding to a particular one of the output interfaces; and

means for responding to the request via the one input interface with the virtual input address associated with the data forwarder and matchable by the matching means to the particular output interface.

12. The data forwarder of claim 11, wherein the request is an ARP request for the MAC address of the particular output interface, wherein the ARP request includes an IP prefix corresponding to the particular output interface.

13. The data forwarder of claim 1, wherein the data receiving means includes means for receiving packets of data, each data packet having one of the virtual addresses in a header of the packet and having the information content in a body of the data packet.

15. The forwarding process of of claim 14, wherein the input interfaces are interface to a local area network (LAN), and the data receiving step is such that all data transmitted over the LAN is received.

16. The forwarding process of claim 15, wherein the LAN is operating under an Ethernet protocol, and all data transmitted over the LAN is received as a result of receiving circuitry being configured in a promiscuous mode.

17. The forwarding process of claim 14, wherein the virtual addresses are MAC addresses.

18. The forwarding process of claim 15, wherein the output interfaces are wide area network (WAN) interfaces.

19. The forwarding process of claim 17, wherein at least some of the WAN interfaces are connected to network routers.

20. The forwarding process of claim 14, wherein the first matching step includes:

providing a table of indications of the output interfaces, the table being indexable by the virtual addresses in the received data.

21. The forwarding process of claim 20, wherein the second matching step further includes:

determining, from the table and using at least a portion of the virtual address in the input data, the indication of the output interface that corresponds to the input address in the input data.

22. The forwarding process of claim 21, wherein the table providing step includes storing the indications of the output interface in the table as a packed group.

23. The forwarding process of claim 21, wherein the output interface indication determining step includes indexing into the table using a portion of the virtual address in the input data as an index.

24. The forwarding process of claim 14, and further comprising:

receiving a request, via one of the input interfaces, for an actual input address corresponding to a particular one of the output interfaces; and

responding to the request via the one input interface with the virtual input address associated with the data forwarder and matchable by the second matching step to the particular output interface

25. The forwarding process of claim 24, wherein the request is an ARP request for the MAC address of the particular output interface, wherein the ARP request includes an IP prefix corresponding to the particular output interface.

26. The forwarding process of claim 14, wherein the data receiving step includes a step of receiving packets of data, each data packet having one of the virtual addresses in a header of the packet and having the information content in a body of the data packet.

14. A process of forwarding data on a computer network, including:

a first matching step, of matching actual addresses of output interfaces with virtual addresses of the output interfaces, the virtual addresses actually associated with a circuit implementing the data forwarding process but only virtually associated with the output interfaces;

receiving data over an input interface, the received data including information content and also having one of the virtual addresses included therein; and

a second matching step, of matching the virtual address in the data to one of the output interfaces, using the result of the first matching step, and transmitting the information content of the data over the output interface to which the address in the data has been matched in the second matching step.