Switched architecture access server

• US 6,252,878 B1
• Filed: 10/30/1997
• Issued: 06/26/2001
• Est. Priority Date: 10/30/1997
• Status: Expired due to Term

• Current Assignee: ITT Manufacturing Enterprises, Inc. (ITT, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Carew, Anthony J. P., Brewer, William K., McClanahan, Kip R., Cantrell, Craig S., Locklear, Robert H. Jr.
• Primary Examiner(s): Olms, Douglas
• Assistant Examiner(s): Pizarro, Ricardo M.
• Application Number:
  US08/960,590
• Time in Patent Office: 1,335 Days
• Field of Search: 370/400, 370/401, 370/403, 370/404, 370/409, 370/464, 370/465, 370/466, 370/467, 370/498
• US Class Current: 370/401
• CPC Class Codes: H04L 2012/561 Star, e.g. cross-connect, concentrator, subscriber group equipment, remote electronics
• CPC Class Codes: H04L 2012/5612 Ring
• CPC Class Codes: H04L 2012/5615 Network termination, e.g. NT1, NT2, PBX
• CPC Class Codes: H04L 2012/5652 Cell construction, e.g. including header, packetisation, depacketisation, assembly, reassembly
• CPC Class Codes: H04L 49/255 Control mechanisms for ATM switching fabrics
• CPC Class Codes: H04L 49/3081 ATM peripheral units, e.g. policing, insertion or extraction
• CPC Class Codes: H04Q 11/0478 Provisions for broadband connections

Abstract

A communication system includes an access server that communicates information between a wide area network (WAN) and a local area network (LAN). The access server includes a WAN interface, a switch fabric, a number of route processors, and a LAN interface. The switch fabric directs information from the WAN interface to a selected route processor based on its loading characteristics.

Claims

1. A communication system, comprising:

a communication device;

a communication server coupled to the communication device using a subscriber line that forms a local loop between the communication device and the communication server; and

anaccess server coupled to the communication server using a data network, the access server comprising a switch fabric coupled to a plurality of route processors, wherein the access server is operable to receive information associated with a session from the communication device, to select one of the route processors for the session based on the route processor'"'"'s loading characteristics, and to communicate the information associated with the session to the selected route processor using the switch fabric.

2. The communication system of claim 1, further comprising a second communication device coupled to the access server and operable to receive information generated by the communication device from the selected route processor.

3. The communication system of claim 1, wherein the selected route processor converts information received from the communication device from a wide area network protocol to a local area network protocol.

4. The communication system of claim 1, wherein the selected route processor converts information received from the communication device from an asynchronous transfer mode protocol to an Ethernet protocol.

5. The communication system of claim 1, wherein the selected route processor terminates information in a first network protocol and routes information in a second network protocol.

6. The communication system of claim 1, wherein the communication device and the communication server communicate via the local loop using XDSL communication techniques.

7. The communication system of claim 1, wherein the loading characteristic for each route processor comprises a packet rate.

8. The communication system of claim 1, wherein the switch fabric establishes a virtual channel that indicates a coupling between the switch fabric and the selected route processor.

9. An access server, comprising:

a first network interface to receive information associated with a session;

a plurality of route processors, each route processor having a loading characteristic indicating its level of activity; and

a switch fabric having a first port and a plurality of second ports, the first port of the switch fabric coupled to the first network interface, each second port of the switch fabric coupled to an associated route processor, the switch fabric operable to select one of the route processors for the session based on the route processor'"'"'s loading characteristics and to communicate the information associated with the session from the first network interface to the selected route processor.

10. The access server of claim 9, wherein the loading characteristic for each route processor comprises a packet rate.

11. The access server of claim 9, wherein the first network interface receives the information on a default channel associated with unassigned sessions.

12. The access server of claim 9, wherein the switch fabric establishes a virtual channel that indicates the coupling between the switch fabric and the selected route processor.

13. The access server of claim 9, wherein the selected route processor converts information associated with the session from a wide area network protocol to a local area network protocol.

14. The access server of claim 9, wherein the selected route processor converts information associated with the session from an asynchronous transfer mode protocol to an Ethernet protocol.

15. The access server of claim 9, wherein the first network interface, the route processors, and the switch fabric reside in a single housing.

16. The access server of claim 9, wherein the selected route processor terminates information associated with the session in a first network protocol and routes information associated with the session in a second network protocol.

53. The access server of claim 9, wherein the switch fabric selects one of the route processors for the session with assistance of a controller.

17. A method for communicating information associated with a session, comprising:

receiving a message indicating the initiation of a session;

determining loading characteristics on at least one of a plurality of route processors;

selecting a route processor for the session based on the loading characteristics; and

switching the message to the selected route processor using a switch fabric.

18. The method of claim 17, wherein the step of determining loading characteristics comprises determining a packet rate.

19. The method of claim 17, wherein the step of receiving comprises receiving the message on a default channel associated with unassigned sessions.

20. The method of claim 17, further comprising the step of converting the message from a first network protocol into a second network protocol at the selected route processor.

21. The method of claim 20, wherein:

the first network protocol comprises asynchronous transfer mode; and

the second network protocol comprises Ethernet.

22. The method of claim 17, further comprising the following steps performed at the selected route processor:

terminating the message in a first network protocol;

assembling the message into a packet in a second network protocol; and

routing the packet in a second network protocol.

23. The method of claim 17, wherein the message comprises an address, and further comprising the step of switching a plurality of additional messages having the address to the selected route processor.

24. The method of claim 23, wherein the address identifies a virtual channel associated with the session.

25. The method of claim 17, wherein the switch fabric comprises an asynchronous transfer mode switch fabric.

26. A communication system, comprising:

a communication device;

a communication server coupled to the communication device using a subscriber line that forms a local loop between the communication device and the communication server; and

an access server coupled to the communication server using a data network, the access server comprising a switch fabric coupled to a plurality of route processors, wherein the access server is operable to receive information associated with a session from the communication device, to select one of the route processors for the session based on the route processor'"'"'s loading characteristics, and to communicate the information associated with the session to the selected route processor using the switch fabric;

wherein the communication device and the communication server communicate via the local loop using XDSL communication techniques.

27. A communication system, comprising:

a communication device;

a communication server coupled to the communication device using a subscriber line that forms a local loop between the communication device and the communication server; and

an access server coupled to the communication server using a data network, the access server comprising a switch fabric coupled to a plurality of route processors, wherein the access server is operable to receive information associated with a session from the communication device, to select one of the route processors for the session based on the route processor'"'"'s packet rate, and to communicate the information associated with the session to the selected route processor using the switch fabric.

28. An access server, comprising:

a first network interface to receive information associated with a session;

a plurality of route processors, each route processor having a loading characteristic indicating its level of activity; and

a switch fabric having a first port and a plurality of second ports, the first port of the switch fabric coupled to the first network interface, each second port of the switch fabric coupled to an associated route processor, the switch fabric operable to select one of the route processors for the session based on the route processor'"'"'s packet rate and to communicate the information associated with the session from the first network interface to the selected route processor.

29. An access server, comprising:

a first network interface to receive information associated with a session;

a plurality of route processors, each route processor having a loading characteristic indicating its level of activity; and

a switch fabric having a first port and a plurality of second ports, the first port of the switch fabric coupled to the first network interface, each second port of the switch fabric coupled to an associated route processor, the switch fabric operable to select one of the route processors for the session based on the route processor'"'"'s loading characteristics and to communicate the information associated with the session from the first network interface to the selected route processor;

wherein the selected route processor converts information associated with the session from an asynchronous transfer mode protocol to an Ethernet protocol.

30. A method for communicating information associated with a session, comprising:

receiving a message indicating the initiation of a session;

determining a packet rate of at least one of a plurality of route processors;

selecting a route processor for the session based on the packet rate; and

switching the message to the selected route processor using a switch fabric.

31. A method for communicating information associated with a session, comprising:

receiving a message indicating the initiation of a session;

determining loading characteristics on at least one of a plurality of route processors;

selecting a route processor for the session based on the loading characteristics;

switching the message to the selected route processor using a switch fabric; and

converting the message from an asynchronous transfer mode protocol into an Ethernet protocol at the selected route processor.

32. A method for communicating information associated with a session, comprising:

receiving a message indicating the initiation of a session, the message comprising an address;

determining loading characteristics on at least one of a plurality of route processors;

selecting a route processor for the session based on the loading characteristics;

switching the message to the selected route processor using a switch fabric; and

switching a plurality of additional messages having the address to the selected route processor.

33. The method of claim 32, wherein the address identifies a virtual channel associated with the session.

34. A method for communicating information associated with a session, comprising:

receiving a message indicating the initiation of a session;

determining loading characteristics on at least one of a plurality of route processors;

selecting a route processor for the session based on the loading characteristics; and

switching the message to the selected route processor using an asynchronous transfer mode switch fabric.

35. Access server software embodied in a computer-readable medium and operable to perform the following steps:

receiving a message indicating an initiation of a session;

determining loading characteristics on at least one of a plurality of route processors;

selecting a route processor for the session based on the loading characteristics; and

switching the message to the selected route processor using a switch fabric.

36. The access server software of claim 35, wherein the step of determining loading characteristics comprises determining a packet rate.

37. The access server software of claim 35, wherein the step of receiving the message comprises receiving the message on a default channel associated with unassigned sessions.

38. The access server software of claim 35, wherein the selected route processor converts the message from a first network protocol into a second network protocol at.

39. The access server software of claim 38, wherein:

the first network protocol comprises asynchronous transfer mode; and

the second network protocol comprises Ethernet.

40. The access server software of claim 35, wherein the selected route processor terminates the message in a first network protocol, assembles the message into a packet in a second network protocol, and routes the packet in a second network protocol.

41. The access server software of claim 35, wherein the message comprises an address and the access server software is further operable to perform the step of switching a plurality of additional messages having the address to the selected route processor.

42. The access server software of claim 41, wherein the address identifies a virtual channel associated with the session.

43. The access server software of claim 35, wherein the switch fabric comprises an asynchronous transfer mode switch fabric.

44. An access server, comprising:

means for receiving a message indicating an initiation of a session;

means for determining loading characteristics on at least one of a plurality of route processors;

means for selecting a route processor for the session based on the loading characteristics; and

means for switching the message to the selected route processor using a switch fabric.

45. The access server of claim 44, wherein the means for determining loading characteristics comprises means for determining a packet rate.

46. The access server of claim 44, wherein the means for receiving the message comprises means for receiving the message on a default channel associated with unassigned sessions.

47. The access server of claim 44, further comprising means for converting the message from a first network protocol into a second network protocol at the selected route processor.

48. The access server of claim 47, wherein:

the first network protocol comprises asynchronous transfer mode; and

the second network protocol comprises Ethernet.

49. The access server of claim 44, wherein the selected route processor terminates the message in a first network protocol, assembles the message into a packet in a second network protocol, and routes the packet in a second network protocol.

50. The access server of claim 44, wherein the message comprises an address, and further comprising means for switching a plurality of additional messages having the address to the selected route processor.

51. The access server of claim 50, wherein the address identifies a virtual channel associated with the session.

52. The access server of claim 44, wherein the switch fabric comprises an asynchronous transfer mode switch fabric.