System and method for combining multiple physical layer transport links

• US 6,775,305 B1
• Filed: 10/19/2000
• Issued: 08/10/2004
• Est. Priority Date: 10/21/1999
• Status: Expired due to Fees

• Current Assignee: Conexant Incorporated (Synaptics Incorporated)
• Original Assignee: GlobespanVirata, Inc. (Synaptics Incorporated)
• Inventors: Delvaux, Marc
• Primary Examiner(s): Chin, Wellington
• Assistant Examiner(s): FOX, JAMAL A
• Application Number:
  US09/691,933
• Time in Patent Office: 1,391 Days
• Field of Search: 370/394, 370/535, 370/537, 370/536, 370/540, 370/474, 370/542, 370/510, 370/518, 370/503, 370/538, 370/539, 370/541, 370/543, 370/544, 370/545, 375/260, 375/257
• US Class Current: 370/535
• CPC Class Codes: H04L 12/5601 Transfer mode dependent, e.g. ATM
• CPC Class Codes: H04L 2012/5624 Path aspects, e.g. path bundling
• CPC Class Codes: H04L 2012/5638 Services, e.g. multimedia, GOS, QOS
• CPC Class Codes: H04L 2012/565 Sequence integrity

Abstract

A multi-channel communication link generates a transport data protocol unit (TPDU) corresponding to each data packet received at a particular interface in a packet switching network. Each TPDU may comprise a data packet in accordance with a standard data transfer protocol and a modified header comprising a sequence number responsive to the relative position of the data packet within a data stream. The multi-channel communication link may inverse multiplex the various TPDUs for transmission across a plurality of asynchronous communication lines. A multi-channel communication link in accordance with the present disclosure may comprise a source first-in first-out (FIFO) buffer, a source line multiplexer/demultiplexer, a plurality of asynchronous communication links, a destination line multiplexer/demultiplexer, and a destination FIFO buffer. The present disclosure also provides a method for transferring data between computing devices via a virtual transport link.

Claims

1. A multi-channel communication system, comprising:

a communication node coupled for data communication over a communications network according to a packet switching data transfer protocol, the communication node configured to receive a stream of data packets in a downstream direction according to a downstream data packet sequence, the communication node further coupled to a plurality of asynchronous communications links, the communication node configured to generate a transport protocol data unit (TPDU) corresponding to each data packet in the received stream, the communication node further configured to inverse multiplex the stream of generated TPDUs for transmission over the plurality of asynchronous communication links;

a destination line multiplexer/demultiplexer coupled for data communication with the plurality of asynchronous communication links, the destination line multiplexer/demultiplexer configured to receive and resequence the stream of TPDUs in accordance with the downstream data packet sequence, the destination line multiplexer/demultiplexer also configured to release a TPDU once it is in the correct sequence order; and

a destination first-in first-out (FIFO) buffer with an input coupled to an output of the destination line multiplexer/demultiplexer and an output coupled to a destination computing device.

2. The communication system of claim 1, wherein data transmissions are performed via a frame relay data transfer protocol.

3. The communication system of claim 1, wherein data transmissions are performed via an asynchronous transfer mode (ATM) data transfer protocol.

4. The communication system of claim 1, wherein the plurality of asynchronous communication links comprise digital subscriber lines (DSLs).

5. The communication system of claim 1, wherein the destination line multiplexer/demultiplexer is configured to hold TPDUs that arrive out of sequence order.

6. The communication system of claim 1, wherein the communication node comprises:

a data packet switch;

a source line multiplexer/demultiplexer coupled for data communication with the plurality of asynchronous communication links, the source line multiplexer/demultiplexer configured to receive and resequence an upstream stream of TPDUs generated in accordance with an upstream data packet sequence inverse multiplexed across the plurality of asynchronous communication links, the source line multiplexer/demultiplexer further configured to release an upstream TPDU once it is in the correct upstream data packet sequence order; and

a source FIFO buffer with an input coupled to an output of the source line multiplexer/demultiplexer and an output coupled to the data packet switch.

7. The communication system of claim 3, wherein the communication node comprises an ATM layer device coupled with a physical layer device.

8. The communication system of claim 5, wherein the destination line multiplexer/demultiplexer releases held TPDUs in response to a timeout mechanism responsive to an expected worse case transport delay skew for a data packet that traverses the communication system.

9. The communication system of claim 7, wherein the communication node generates each TPDU in response to the position of the corresponding data packet within the data packet sequence as the corresponding data packet traverses an interface between the ATM layer device and the physical layer device.

10. The communication system of claim 8, wherein the destination line multiplexer/demultiplexer releases held TPDUs in response to a TPDU release delay determined during initialization of the various DSLs comprising the physical transport layer.

11. The communication system of claim 9, wherein each TPDU comprises a data packet and a sequence number.

12. The communication system of claim 10, wherein the TPDU release delay is determined based on expected performance characteristics.

13. A multi-channel communication system, comprising:

means for communicating with at least one network node configured to send the system a downstream data transmission and to receive an upstream data transmission;

means for identifying a data transmission sequence corresponding to each respective downstream and upstream data transmission, accomplished by generating a transport protocol data unit (TPDU) as data packets traverse an interface between an asynchronous transfer mode (ATM) layer device and a physical layer device;

means for distributing a portion of each downstream and upstream data transmission to each of a plurality of asynchronous communication links for transmission to a destination computing device; and

means for combining the distributed portions of each downstream and upstream data transmission received from the plurality of asynchronous links wherein the original data transmission sequence is restored.

14. The communication system of claim 13, wherein data transmissions are performed via a data transfer protocol that supports data packet switching.

15. The communication system of claim 13, wherein the plurality of asynchronous communication links comprise digital subscriber lines (DSLs).

16. The communication system of claim 13, wherein the means for combining the distributed portions of each downstream and upstream data transmission comprises a line multiplexer/demultiplexer and a first-in first-out buffer.

17. The communication system of claim 14, wherein data transmissions are performed via a frame relay data transfer protocol.

18. The communication system of claim 14, wherein the data tansfer protocol is an asynchronous transfer mode (ATM) data transfer protocol.

19. The communication system of claim 16, wherein the line multiplexer/demultiplexer is configured to release each data packet received in the correct sequence.

20. The communication system of claim 18, wherein the TPDU comprises an ATM cell with a modified header, the ATM cell header comprising a sequence number responsive to the order in which the ATM cell traversed the interface.

21. The communication system of claim 19, wherein the line multiplexer/demultiplexer is configured to hold each received out of sequence data packet for a predetermined time responsive to a worst case transmission skew between the plurality of asynchronous links of the system.

22. A method for transmitting data to a remote computing device via a virtual transport link, comprising:

applying a sequence number to each data packet of a data stream to be transported to generate a transport protocol data unit (TPDU) in accordance with the relative position of each data packet in the data stream as each data packet traverses an interface between an ATM layer device and a physical transport layer device;

mapping each TPDU to a designated communication line such that a portion of the data stream is designated for transmission by each of a plurality of asynchronous communication lines; and

releasing each mapped TPDU to the designated communication line.

23. The method of claim 22, wherein the step of mapping is accomplished with a plurality of asynchronous communication lines comprising digital subscriber lines.

24. The method of claim 22, wherein the step of applying a sequence number is accomplished in an ATM layer device.

25. The method of claim 22, wherein the step of applying a sequence number is accomplished in a physical layer device.

26. A method for receiving data from a remote computing device via a virtual transport link, comprising:

receiving a plurality of inverse multiplexed transport protocol data units (TPDUs) comprising a data packet and a sequence number via a plurality of asynchronous communication lines; and

identifying the corresponding sequence number for each received TPDU;

releasing the corresponding data packet in the case where the identified sequence number matches an expected sequence counter, otherwise resequencing the corresponding data packets in the case where the identified sequence number fails to match the expected sequence counter.

27. The method of claim 26, wherein the step of

releasing the corresponding data packet is performed after the last preceding TPDU received in the expected sequence order has remained in the system for a predetermined period.

28. The method of claim 26, wherein the step of receiving a plurality of inverse multiplexed TPDUs is accomplished with a plurality of asynchronous communication lines comprising digital subscriber lines.

29. The method of claim 26, wherein the data packets are formulated in accordance with a data transfer protocol.

30. The method of claim 26, wherein the data packets are formulated in accordance with a frame relay data transfer protocol.

31. The method of claim 28, wherein the data transfer protocol comprises an asynchronous transfer mode (ATM) protocol.

32. The method of claim 26, further comprising:

communicating the received and sequence verified data packets to a destination computing device.