Data communication using a modifiable number of XDSL modems

• US 5,999,565 A
• Filed: 10/15/1997
• Issued: 12/07/1999
• Est. Priority Date: 10/15/1997
• Status: Expired due to Term

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: McClanahan, Kip R., Cantrell, Craig S., Locklear, Robert H. Jr.
• Primary Examiner(s): Horabik, Michael
• Assistant Examiner(s): Tadesse, Binyam
• Application Number:
  US08/951,151
• Time in Patent Office: 783 Days
• Field of Search: 370/485, 370/486, 370/487, 370/493, 370/494, 370/522, 370/490, 370/401, 370/468, 375/222, 375/260, 375/257, 379/93.01, 379/93.07, 379/93.14, 379/93.29, 379/93.05
• US Class Current: 375/222
• CPC Class Codes: H04L 25/14 Channel dividing arrangements , i.e. in which a single bit stream is divided between several baseband channels and reassembled at the receiver
• CPC Class Codes: H04M 11/062 using different frequency bands for speech and other data

Abstract

A communication system includes a number of communication devices coupled to a data network using communication servers. The communication system supports communication sessions between a variety of networks and devices using, at least in part, XDSL communication techniques. Specifically, information associated with a session passes between a device and an associated server using a modifiable number of XDSL modems and associated twisted pair lines.

Claims

1. A communication system for communicating data associated with a session, comprising:

a plurality of twisted pair lines;

a first communication device having a plurality of first XDSL modems coupled to the twisted pair lines, the first communication device operable to communicate data associated with the session using the twisted pair lines; and

a second communication device having a plurality of second XDSL modems coupled to the twisted pair lines and operable to communicate with the first XDSL modems, wherein the second communication device determines the number of second XDSL modems for communicating data associated with the session based on loading information and corresponding threshold information of at least one of the second XDSL modems.

2. The communication system of claim 1, wherein the second communication device comprises:

a network interface;

a router for communicating data between the network interface and the second XDSL modems; and

a controller coupled to the second XDSL modems and the router, wherein the controller receives the loading information from at least one of the second XDSL modems, compares the loading information to stored threshold information, and determines the number of second XDSL modems for communicating data associated with the session.

3. The communication system of claim 1, wherein the first communication device further comprises a switch coupled to the twisted pair lines and the first XDSL modems, the switch operable to couple each twisted pair line to a selected first XDSL modem in response to a request received on the twisted pair line.

4. The communication system of claim 1, wherein:

the first XDSL modems communicate information to the second XDSL modems at a first rate; and

the second XDSL modems communicate information to the first XDSL modems at a second rate less than the first rate.

5. The communication system of claim 1, wherein loading information comprises a plurality of data rates over successive intervals of time, wherein each data rate is compared to the threshold information to determine the number of second XDSL modems for communicating data associated with the session.

6. The communication system of claim 1, wherein loading information and corresponding threshold information for each second XDSL modem further comprises:

a downstream data rate for data received by the second XDSL modem;

an upstream data rate for data communicated by the second XDSL modem;

an upstream add threshold for comparison to the upstream data rate;

an upstream remove threshold for comparison to the upstream data rate;

a downstream add threshold for comparison to the downstream data rate; and

a downstream remove threshold for comparison to the downstream data rate.

7. The communication system of claim 1, wherein the second communication device is operable to communicate a request for service upon determining to add another second XDSL modem.

8. The communication system of claim 1, wherein the first communication device is located at a central office.

9. The communication system of claim 1, wherein the twisted pair lines each form a local loop between the first communication device and the second communication device.

10. A communication device for communicating data associated with a session using a plurality of twisted pair lines, the device comprising:

a plurality of XDSL modems coupled to the twisted pair lines;

an interface;

a router for communicating data between the interface and the XDSL modems; and

a controller coupled to the XDSL modems and the router, wherein the controller receives loading information from at least one of the XDSL modems, compares the loading information to stored threshold information, and determines the number of XDSL modems for communicating data associated with the session.

11. The device of claim 10, wherein loading information comprises a plurality of data rates over successive intervals of time, wherein each data rate is compared to the threshold information to determine the number of XDSL modems for communicating data associated with the session.

12. The device of claim 10, wherein loading information and corresponding threshold information for each XDSL modem further comprises:

a downstream data rate for data received by the XDSL modem;

an upstream data rate for data communicated by the XDSL modem;

an upstream add threshold for comparison to the upstream data rate;

an upstream remove threshold for comparison to the upstream data rate;

a downstream add threshold for comparison to the downstream data rate; and

a downstream remove threshold for comparison to the downstream data rate.

13. The device of claim 10, wherein the XDSL modems receive information at a first rate and transmit information at a second rate less than the first rate.

14. The device of claim 10, wherein the device communicates a request for service upon determining to add another XDSL modem.

15. The device of claim 10, wherein the router performs open systems interconnect (OSI) model processing of data communicated between the interface and the XDSL modems.

16. A communication device for communicating data using a plurality of twisted pair lines, the device comprising:

a plurality of XDSL modems;

a first switch coupled to the plurality of XDSL modems, the first switch operable to couple selected twisted pair lines to the XDSL modems;

an interface;

a second switch for communicating data between the XDSL modems and the interface; and

a controller coupled to the XDSL modems, wherein the controller modifies the number of XDSL modems for communicating data associated with the session based on loading information and corresponding threshold information of at least one of the XDSL modems.

17. The device of claim 16, wherein loading information comprises a plurality of data rates over successive intervals of time, wherein each data rate is compared to the threshold information to determine the number of XDSL modems for communicating data associated with the session.

18. The device of claim 16, wherein loading information and corresponding threshold information for each XDSL modem further comprises:

a downstream data rate for data received by the XDSL modem;

an upstream data rate for data communicated by the XDSL modem;

an upstream add threshold for comparison to the upstream data rate;

an upstream remove threshold for comparison to the upstream data rate;

a downstream add threshold for comparison to the downstream data rate; and

a downstream remove threshold for comparison to the downstream data rate.

19. The device of claim 16, wherein the XDSL modems receive information at a first rate and transmit information at a second rate greater than the first rate.

20. The device of claim 16, wherein the device communicates a request for service upon determining to add another XDSL modem.

21. The device of claim 16, wherein the first switch comprises a cross-point matrix switch.

22. The device of claim 16, wherein the device is located at a central office.

23. The device of claim 16, wherein the second switch comprises a switching fabric coupled to the XDSL modems, wherein the switching fabric combines data received from the XDSL modems into a single data stream for communication by the interface.

24. A method for communicating data using a plurality of XDSL modems coupled to a plurality of associated twisted pair lines, the method comprising:

determining loading information of at least one XDSL modem;

comparing the loading information to threshold information; and

determining the number of XDSL modems for communicating data associated with a session in response to the comparison.

25. The method of claim 24, wherein determining the number of XDSL modems for communicating data associated with a session further comprises:

adding an XDSL modem if the loading information exceeds corresponding threshold information; and

removing an XDSL modem if the loading information falls below corresponding threshold information.

26. The method of claim 24, wherein loading information and corresponding threshold information for each XDSL modem further comprises:

a downstream data rate for data received by the XDSL modem;

an upstream data rate for data communicated by the XDSL modem;

an upstream add threshold for comparison to the upstream data rate;

an upstream remove threshold for comparison to the upstream data rate;

a downstream add threshold for comparison to the downstream data rate; and

a downstream remove threshold for comparison to the downstream data rate.

27. The method of claim 24, wherein the loading information further comprises a packet rate, a bit rate, or an error rate.

28. The method of claim 24, wherein determining the number of XDSL modems for communicating data associated with the session further comprises:

adding an XDSL modem if an upstream data rate exceeds an upstream add threshold or a downstream data rate exceeds a downstream add threshold; and

removing an XDSL modem if the upstream data rate falls below an upstream remove threshold and the downstream data rate falls below a downstream remove threshold.

29. The method of claim 24, wherein the plurality of XDSL modems are located at a central office.

30. The method of claim 24, wherein the number of XDSL modems is less than the number of twisted pair subscriber lines.

31. A method for segmenting a packet of data for communication by a plurality of XDSL modems, the method comprising:

receiving a packet;

determining the size of the packet; and

segmenting the packet into a plurality of subpackets based on a plurality of proportionality factors associated with a plurality of XDSL modems; and

communicating the subpackets using the XDSL modems.

32. The method of claim 31, further comprising the step of addressing each subpacket to a different switched circuit.

33. The method of claim 31, further comprising the step of modifying the proportionality factors in response to a modification in the number of XDSL modems to communicate the subpackets.

34. The method of claim 31, further comprising the step of modifying the proportionality factors in response to a change in the data rate of an XDSL modem.

35. The method of claim 31, wherein the proportionality factors for each XDSL modem further comprise:

an upstream proportionality factor; and

a downstream proportionality factor.

36. The method of claim 31, wherein each proportionality factor comprises a ratio between the data rate of its associated XDSL modem and the sum of data rates of the XDSL modems.