Methods, apparatuses and systems facilitating aggregation of physical links into logical link

• US 6,879,590 B2
• Filed: 07/24/2002
• Issued: 04/12/2005
• Est. Priority Date: 04/26/2002
• Status: Expired due to Fees

• Current Assignee: Klamath Networks Corporation
• Original Assignee: Valo, Inc.
• Inventors: May, Lauren Trevor, Thom, Danny, Shilshtut, Radimir, Soltani, Sina, Pedersen, Soren Bo
• Primary Examiner(s): QURESHI, AFSAR M
• Application Number:
  US10/202,108
• Publication Number:
  US 20040062198A1
• Time in Patent Office: 993 Days
• Field of Search: 37039551-39553, 370/394, 370/412, 370901-907, 370/389, 370/392, 370/395.1, 370/397, 370/399, 3703953-3954, 370/409
• US Class Current: 370/394
• CPC Class Codes: H04L 45/00 Routing or path finding of packets in data switching networks routing or path finding in wireless networks H04W40/00
• CPC Class Codes: H04L 45/245 Link aggregation, e.g. trunking
• CPC Class Codes: H04M 11/062 using different frequency bands for speech and other data
• CPC Class Codes: Y02D 30/50 in wire-line communication networks, e.g. low power modes or reduced link rate

Abstract

Methods, apparatuses and systems facilitating the aggregation or bonding of physical communications links into higher-bandwidth logical links. A novel link bonding and encapsulation protocol scheme that optimizes the efficiency of data transfer across the physical links, while still allowing for desired Quality of Service (QoS) levels to high-priority traffic, such as voice data, with low delay requirements. Data streams are divided and concurrently transported over multiple physical links that are aggregated or bonded together to form one logical link. At the receive end, the original cell streams are recovered from the bonded logical links. In one embodiment, the physical links are xDSL links transmitting and receiving signals via conventional copper twisted-pair cabling. In one embodiment, the present invention allows telecommunications service providers to leverage their investments in existing twisted pair connection technologies to deliver high-bandwidth services to customers in a fast and cost-efficient manner.

Claims

1. An apparatus facilitating aggregation of at least two physical links into a logical link, comprising

at least one native link interface operative to:

receive native flows and transform the native flow into a plurality of user cells,

a link bonding engine operative to;

receive the plurality of user cells from the at least one native link interface,

associate a sequence number to each of the plurality of user cells,

schedule the plurality of user cells for transmission across one or more bonded links,

at least two bonded link interfaces, wherein the at least two bonded link interfaces are operative to;

receive user cells from the link bonding engine,

aggregate the user cells into bonded link frames, wherein the bonded link frame header includes the sequence number associated with the first user cell in the bonded link frame, and

transmit the bonded link frames across a physical link,

wherein the at least two bonded link interfaces aggregate a maximum number of cells into a given bonded link frame, wherein the maximum number of cells is determined relative to the speed of the physical link and the size of the resulting bonded link frame, and

wherein the link bonding engine schedules the plurality of user cells for transmission across the bonded links by arbitrating among the at least two bonded link interfaces, wherein the number of cells passed to each of the bonded link frames is the maximum number of cells that each bonded link interface aggregates into a bonded link frame.

2. The apparatus of claim 1 wherein the at least two bonded link interfaces are further operative to:

receive bonded link frames, including a plurality of user cell payloads and a sequence number associated with the first user cell payload in the plurality, transmitted across a physical link,

restore the user cells including their associated sequence numbers from the bonded link frames;

wherein the link bonding engine is further operative to;

receive the individual cells from the at least two bonded link interfaces,

sequence the individual cells based on their associated sequence numbers; and

wherein the native link interface is operative to;

convert the individual cells into a native cell format, and

transmit the native cells to a remote device.

3. The apparatus of claim 1 wherein the at least two bonded link interfaces are xDSL interfaces.

4. The apparatus of claim 1 wherein the at least one native interface comprises a DSl interface.

5. The apparatus of claim 1 wherein the at least one native interface comprises an Ethernet interface.

6. The apparatus of claim 1 wherein the at least one native interface comprises an ATM interface.

7. An apparatus facilitating aggregation of at least two physical links into a logical link, comprising

at least one native link interface operative to:

receive native flows and transform the native flow into a plurality of user cells,

a link bonding engine operative to;

receive the plurality of user cells from the at least one native link interface,

associate a sequence number to each of the plurality of user cells,

schedule the plurality of user cells for transmission across one or more bonded links,

at least two bonded link interfaces, wherein the at least two bonded link interfaces are operative to;

receive user cells from the link bonding engine,

aggregate the user cells into bonded link frames, wherein the bonded link frame header includes the sequence number associated with the first user cell in the bonded link frame, and

transmit the bonded link frames across a physical link, wherein the bonded link frame header further comprises the cell payloads corresponding to the user cells ordered according to the sequence numbers associated with each cell payload.

8. The apparatus of claim 7 wherein the at least two bonded link interfaces aggregate a maximum number of cells into a given bonded link frame.

9. The apparatus of claim 8 wherein the maximum number of cells is determined relative to the speed of the physical link and the size of the resulting bonded link frame.

10. The apparatus of claim 8 wherein the link bonding engine schedules the plurality of user cells for transmission across the bonded links by arbitrating among the at least two bonded link interfaces, wherein the number of cells passed to each of the bonded link frames is the maximum number of cells that each bonded link interface aggregates into a bonded link frame.

11. An apparatus facilitating aggregation of at least two physical links into a logical link, comprising

at least one native link interface operative to:

receive native flows and transform the native flow into a plurality of user cells,

a link bonding engine operative to;

receive the plurality of user cells from the at least one native link interface,

associate a sequence number to each of the plurality of user cells,

schedule the plurality of user cells for transmission across one or more bonded links,

at least two bonded link interfaces, wherein the at least two bonded link interfaces are operative to;

receive user cells from the link bonding engine,

aggregate the user cells into bonded link frames, wherein the bonded link frame header includes the sequence number associated with the first user cell in the bonded link frame, wherein the link bonding engine is further operative to generate a super frame upon a sequence number rollover event and transmit a copy of the super frame to the at least two bonded link interfaces for transmission across the physical links, wherein the super frame includes a super frame sequence number.

12. An apparatus facilitating aggregation of at least two physical links into a logical link, comprising

at least one native link interface operative to:

receive native flows and transform the native flow into a plurality of user cells,

a link bonding engine operative to;

receive the plurality of user cells from the at least one native link interface,

associate a sequence number to each of the plurality of user cells,

schedule the plurality of user cells for transmission across one or more bonded links,

at least two bonded link interfaces, wherein the at least two bonded link interfaces are operative to;

receive user cells from the link bonding engine,

aggregate the user cells into bonded link frames, and

transmit the bonded link frames across a physical link,

wherein the link bonding engine comprises a frame scheduler, a bonded link queue, a sequence number generator and a port queue scheduler;

wherein the frame scheduler is operative to push identifiers each corresponding to individual user cells associated with a complete native frame onto the bonded link queue;

wherein the port queue scheduler, based on the state of the bonded link queue, is operative to schedule individual users cells associated with complete native frame for transmission across one or more physical links; and

wherein the sequence number generator is operative to generate a contiguous sequence number for the individual user cells scheduled by the port queue scheduler.

13. The apparatus of claim 12 wherein the sequence number generator is further operative to generate a super frame at a sequence number roll-over event and transmit the super frame to the port queue scheduler and transmit a copy of the super frame to the at least two bonded link interfaces for transmission across the physical links.

14. An apparatus facilitating aggregation of at least two physical links into a logical link, comprising

at least two bonded link interfaces operative to:

receive bonded link frames, including a plurality of user cell payloads and a sequence number associated with the first user cell payload in the plurality, transmitted across a physical link,

restore the user cells including their associated sequence numbers from the bonded link frames,

a link bonding engine operative to;

receive the individual cells from the at least two bonded link interfaces,

sequence the individual cells based on their associated sequence numbers, wherein the link bonding engine comprises a sequence queuing module operative to buffer individual user cells based on their corresponding sequence numbers; and

at least one native link interface operative to;

convert, the individual cells into a native cell format, and

transmit the native cells to a remote device.

15. The apparatus of claim 14 wherein the link bonding engine is operative to:

receive an individual cell into a cell memory;

insert a pointer to the individual cell into the sequence queue based upon the sequence number associated with the individual cell;

schedule the individual cell for transmission by reading the pointer to the individual cell from the sequence queue a given delta amount of time after receiving the individual cell.

16. The apparatus of claim 15 wherein the delta amount is a predetermined amount of time.

17. The apparatus of claim 15 wherein the delta amount is based upon a real-time evaluation of at least one characteristic associated with the physical links.

18. The apparatus of claim 17 wherein the at least one characteristic is link speed.

19. The apparatus of claim 17 wherein the at least one characteristic is packetization delay.

20. A method allowing for aggregation of a plurality of physical links into a logical link, comprising

receiving a native flow;

transforming the native flow into user cells;

associating a sequence number to each of the plurality of user cells;

aggregating the user cells into bonded link frames, wherein the bonded link frames include at least one sequence number corresponding to one of the user cells; and

transmitting the bonded link frames across one or more physical links of the plurality of physical links;

wherein the number of cell payloads in each bonded link frame depends on the link speed of the physical link over which it is transmitted, and wherein the bonded link frame comprises a plurality of user cell payloads and a sequence number associated with the first user cell payload in the plurality of user cell payloads;

receiving the bonded link frames;

recovering the user cells from the bonded link frames;

re-sequencing the user cells based on the sequence numbers associated with the user cells; and

transforming the user cells into a native flow format; and

wherein the recovering step comprises

generating an individual user cell including the sequence number and the first cell payload;

incrementing the sequence number and repeating the generating step for all remaining user cell payloads in the plurality.

21. A system allowing for aggregation of a plurality of physical links into a logical link, comprising

a first link bonding engine operably coupled via a plurality of physical links to a second link bonding engine;

wherein the first link bonding engine is operative to;

receive native data streams;

convert native data streams into user cells of uniform size;

associate contiguous sequence numbers to the user cells;

aggregate the user cells into bonded link frames, wherein the bonded link frames comprise at least one user cell payload and the sequence number associated with the first of the at least one user cell payload; and

transmit the bonded link frames across at least one of the plurality of physical links;

wherein the size of each bonded link frame is determined by the speed of the physical link over which it is transmitted and a maximum delay time;

wherein the second link bonding engine is operative to recover the native data stream from the bonded link frames, and wherein the second link bonding engine is operative to;

receive the bonded link frames;

recover the user cells based on the sequence number and use cell payloads of each bonded link frame; and

sequence the user cells based on the sequence numbers associated with each user cell.

22. The system of claim 21 wherein the number of user cell payloads in each bonded link frame depends on the speed of the physical link over which it is transmitted.