High layer bonding of multiple access lines for carrier grade access
View Patent ↗Apparatus and method that increases bandwidth and reliability of digital subscriber line (DSL) connections. The system involves provisioning multiple DSL lines, splitting traffic into cells, transmitting the cells independently of each other, and reassembling the cells at the destination. Sequence numbers may be used when reassembling the cells. Virtual circuits (VCs) may be constructed across the DSL lines. Accordingly, a failure in one DSL line merely reduces the bandwidth without disruption to the customer. In this manner, the customer can be inexpensively provided with increased bandwidth and reliability.
1. A multiplexing system for use with a digital subscriber loop (DSL) communication system including at least two parallel DSL links and a switching fabric, said multiplexing system comprising:
a) a first end point at a consumer premise for receiving a stream of data cells and multiplexing said data cells onto a plurality of virtual circuits (VCs), each of said VCs capable of being independently routed across said switching fabric, wherein said consumer premise includes two parallel DSL links connected to said first end point and said switching fabric for transmitting said multiplexed data cells in parallel from said first end point at said consumer premise over said two parallel DSL links to said switching fabric; and
b) a second end point for receiving and demultiplexing said data cells from said plurality of virtual circuits via said two parallel DSL links, said second end point for organizing said data cells after receipt and outputting said data cells after organization in an output data stream.
2. A system as defined in claim 1 , wherein said data cells after being multiplexed each include a sequence number for identifying an offset from a predefined cell, and said second end point organizes said data cells after receipt in accordance with a respective sequence number of each of said data cells.
3. A system as defined in claim 2 , wherein said first end point further includes a scheduler for multiplexing said data cells.
4. A system as defined in claim 3 , wherein said scheduler assigns said data cells to said plurality of VCs in accordance with an available bandwidth on each of said plurality of VCs.
5. A system as defined in claim 4 , wherein said scheduler assigns said data cells to said plurality of VCs in accordance with a peak cell rate on each of said plurality of VCs.
6. A system as defined in claim 2 , wherein said sequence number is imbedded into a payload of each of said data cells.
7. A system as defined in claim 6 , wherein said sequence number occupies a predefined portion of said payload.
8. A system as defined in claim 2 , wherein said sequence number is imbedded into a predefined portion of a virtual channel identifier (VCI) of each of said data cells.
9. A system as defined in claim 2 , wherein said sequence number is imbedded into a predefined portion of a virtual path identifier (VPI) of each of said data cells.
10. A system as defined in claim 2 , wherein said sequence number is dynamically imbedded into at least one of a VPI and a VCI of each of said data cells, and a corresponding masking signal is provided for enabling intermediate switches in said switching fabric to ignore said sequence number when routing each of said data cells.
11. A system as defined in claim 10 , wherein said second end point uses said masking signal for identifying said sequence number.
12. A system as defined in claim 1 , wherein each of said DSL links is a Plain Old Telephone System (POTS) line terminating at said consumer premise first end point.
13. A system as defined in claim 1 , where more than two DSL links couple said first and second end points.
14. A system as defined in claim 13 , wherein said plurality of VCs is carried over each of said plurality of DSL links.
15. A system as defined in claim 13 , wherein a respective single VC is carried over each of said plurality of DSL links.
16. A system as defined in claim 1 , wherein said first end point further includes a scheduler for multiplexing said data cells and said second end point further includes:
a) a transmission rate detector for detecting a transmission rate of each of said plurality of VCs; and
b) a scheduler for demultiplexing each of said plurality of VCs in accordance with an associated detected transmission rate.
17. A system as defined in claim 1 , where a plurality of DSL links couple said first and second end points in parallel.
18. A system as defined in claim 17 , wherein said plurality of VCs is carried over each of said plurality of DSL links.
19. A system as defined in claim 1 , wherein each said VC is capable of beign independently routed across said two parallel DSL links and across said switching fabric.
20. A method of multiplexing data over a digital subscriber loop (DSL) communication system including at least one DSL link and a switching fabric, said method comprising the steps of:
organizing said data in cells;
distributing said cells across a plurality of virtual circuits (VCs);
transmitting said cells over said at least one DSL link to a destination across each of said plurality of VCs, each of said plurality of VCs being switched across said switching fabric independently;
reassembling said cells at said destination for recovering said data; and
outputting said data at a rate greater than that of any single one of said plurality of VCs.
21. A method as defined in claim 20 , further including:
inserting a sequence number into each of said cells before transmitting said cells to said destination.
22. A method as defined in claim 21 , wherein said step of reassembling said cells includes organizing said cells in accordance with a respective sequence number of each of said cells.
23. A method as defined in claim 22 , wherein said sequence number is included in a header of each of said cells.
24. A method as defined in claim 23 , wherein said sequence number is included in a Virtual Path Identifier field of said header.
25. A method as defined in claim 23 , wherein said sequence number is included in a Virtual Channel Identifier field of said header.
26. A method as defined in claim 22 , wherein said sequence number is included in a payload of each of said cells.
27. A method as defined in claim 20 , further including:
inserting a marker cell in each of said plurality of VCs at predetermined intervals such that a transmission rate of each of said plurality of VCs can be determined at said destination.
28. A method as defined in claim 27 , wherein said step of reassembling said cells includes organizing said cells in accordance with a respective transmission rate of each of said plurality of VCs.
29. A method of claim 20 , further comprising:
providing a consumer premise with at least two DSL links connected to a first end point;
receiving a stream of data at said first end point for multiplexing;
multiplexing said data prior to distributing said cells;
transmitting said cells over at least two parallel DSL links from said first end point to said destination.
30. A method of claim 29 , wherein when one of said at least two parallel DSL links fails, said VCs are automatically switched to another of said at least two parallel DSL links.
31. A multiplexing system for use with a digital subscriber loop (DSL) communication system including at least one DSL link and a switching fabric, said multiplexing system comprising:
a) a first end point at a consumer premise for receiving a stream of data cells and multiplexing said data cells onto a plurality of virtual circuits (VCs), each of which VC capable of being independently routed across said switching fabric; and
b) a second end point for receiving said multiplexed data cells over said plurality of virtual circuits from said DSL link and demultiplexing said data cells from said plurality of virtual circuits via said DSL communication system, said second end point for organizing said data cells after receipt and outputting said data cells after organization in an output data stream; wherein at least two parallel DSL links connect said first end point for carrying said multiplexed data cells in parallel over said two parallel DSL links to switching fabric.