Configurable network router

• US 7,933,266 B2
• Filed: 04/20/2004
• Issued: 04/26/2011
• Est. Priority Date: 01/15/1999
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Adler, John Conlon, Parsi, Vahid, Baghdasarian, Zareh, Zadikian, Haig Michael, Saleh, Ali Najib
• Primary Examiner(s): Nguyen; Hanh
• Application Number:
  US10/828,246
• Publication Number:
  US 20040196838A1
• Time in Patent Office: 2,562 Days
• Field of Search: 370/389, 370/384, 370/385, 370/395.1, 370/395.2, 370/395.3, 370/400, 370/408, 370/409, 370/410, 370/419, 370/420, 370/421, 370/907, 370/908, 370/254, 370/259, 370/352, 348/7, 359/125, 359/128, 359/133, 359/137
• US Class Current: 370/389
• CPC Class Codes: H04J 14/0227 Operation, administration, maintenance or provisioning [OAMP] of WDM networks, e.g. media access, routing or wavelength allocation
• CPC Class Codes: H04J 14/0241 Wavelength allocation for communications one-to-one, e.g. unicasting wavelengths
• CPC Class Codes: H04J 14/0284 WDM mesh architectures
• CPC Class Codes: H04J 14/0294 Dedicated protection at the optical channel (1+1)
• CPC Class Codes: H04J 14/0295 Shared protection at the optical channel (1:1, n:m)
• CPC Class Codes: H04L 2012/5605 Fibre
• CPC Class Codes: H04L 2012/5627 Fault tolerance and recovery
• CPC Class Codes: H04L 45/583 Stackable routers
• CPC Class Codes: H04L 49/101 using crossbar or matrix
• CPC Class Codes: H04L 49/15 Interconnection of switching modules
• CPC Class Codes: H04L 49/254 Centralised controller, i.e. arbitration or scheduling
• CPC Class Codes: H04L 49/255 Control mechanisms for ATM switching fabrics
• CPC Class Codes: H04L 49/30 Peripheral units, e.g. input or output ports
• CPC Class Codes: H04L 49/3081 ATM peripheral units, e.g. policing, insertion or extraction
• CPC Class Codes: H04L 49/351 for local area network [LAN], e.g. Ethernet switches
• CPC Class Codes: H04L 49/357 Fibre channel switches
• CPC Class Codes: H04L 49/45 Arrangements for providing or supporting expansion
• CPC Class Codes: H04L 49/55 Prevention, detection or correction of errors
• CPC Class Codes: H04Q 11/0005 Switch and router aspects
• CPC Class Codes: H04Q 11/0071 Provisions for the electrical-optical layer interface
• CPC Class Codes: H04Q 11/0478 : Provisions for broadband connections
• CPC Class Codes: H04Q 2011/0039 : Electrical control
• CPC Class Codes: H04Q 2011/0043 : Fault tolerance
• CPC Class Codes: H04Q 2011/0045 : Synchronisation
• CPC Class Codes: H04Q 2011/0047 : Broadcast; Multicast
• CPC Class Codes: H04Q 2011/0052 : Interconnection of switches
• CPC Class Codes: H04Q 2011/0081 : Fault tolerance; Redundancy; Recovery; Reconfigurability
• CPC Class Codes: H04Q 2011/0088 : Signalling aspects

Abstract

A signal router, configured to receive information carried by a first signal and transmit the information on a second signal, is described. The signal router, using routing information it gathers, selects the second signal from a number of signals, with the first and the second signals differing in at least one physical characteristic. The signal router operates in a network of a number of such signal routers, and so each one of the signal routers is coupled to at least one of the other signal routers. The routing information is used to create a circuit from a first one of the signal routers to a second one of the signal routers. Once the circuit is created, the information is routed over the circuit. According to one aspect of the present invention, the signals are optical signals.

Claims

1. A network element comprising:

a switching matrix, wherein

said network element is configured to

receive a first optical carrier, and

transmit a first plurality of optical carriers, and

said switching matrix is configured to

dynamically select a second optical carrier of said first plurality of optical carriers based at least in part on routing information,

said routing information is derived at least in part from stored topology information stored in a computer-readable storage element within said network element, and

said stored topology information is based at least in part on information encoded in said first optical carrier.

2. The network element of claim 1, further comprising:

a receiver configured to receive said first optical carrier; and

a transmitter configured to transmit said second optical carrier;

wherein

said switching matrix is coupled to said receiver and said transmitter, and

said switching matrix is configured to dynamically select said second optical carrier by virtue of being configured to select said transmitter using said routing information.

3. The network element of claim 2, further comprising:

a plurality of transmitters, wherein

each of said plurality of transmitters is coupled to said switching matrix and said receiver, and

said plurality of transmitters comprise said transmitter.

4. The network element of claim 3, wherein

said switching matrix is configured to dynamically select said second optical carrier by virtue of being configured to select said transmitter from said plurality of transmitters.

5. The network element of claim 2, further comprising:

a signal path through said switching matrix; and

a control path coupled to said signal path.

6. The network element of claim 5, wherein said control path comprises

a hierarchical network of control elements.

7. The network element of claim 6, wherein said hierarchical network of control elements comprises:

a group matrix coupled to said switching matrix, said receiver, and said transmitter.

8. The network element of claim 7, wherein

said receiver comprises a plurality of input channels, and

said group matrix is configured to select a working channel from said plurality of input channels.

9. The network element of claim 7, wherein said hierarchical network of control elements further comprises:

a shelf switch coupled to said switching matrix.

10. The network element of claim 7, wherein said hierarchical network of control elements further comprises:

a system switch coupled to said switching matrix.

11. The network element of claim 7, wherein

said network element is further configured to receive a second plurality of optical carriers including said first optical carrier, and

said switching matrix is further configured to select said first optical carrier from said second plurality of carriers.

12. The network element of claim 7, wherein

said network element is configured to obtain said routing information by virtue of being configured to send a message to at least one other of a plurality of network elements,

said message causes said at least one other of said plurality of network elements to send a response message to said network element, and

said response message comprises received topology information stored on said at least one other of said plurality of network elements.

13. The network element of claim 12, wherein

said received topology information represents a topology of at least a portion of a network comprising said network element and said plurality of network elements, and

said received topology information comprises information received via said first optical carrier.

14. The network element of claim 13, wherein said information received via said first optical carrier is received in response to a request for path restoration.

15. The network element of claim 7, wherein said second optical carrier has a different wavelength from said first optical carrier.

16. The network element of claim 7, wherein

each of said first optical carrier and said second optical carrier comprise a synchronous optical network (SONET) signal.

17. The network element of claim 1, wherein

said switching matrix comprises a plurality of matrix element stages, and

a butterfly connection stage coupled between said plurality of matrix element stages.

18. The network element of claim 1, wherein

said network element is configured to receive information encoded in said first optical carrier and transmit said information encoded in said second optical carrier;

and

said second optical carrier has a different wavelength from said first optical carrier.

19. The network element of claim 1, wherein

said switching matrix comprises a plurality of matrix element stages.

20. The network element of claim 19, wherein

said information comprises a plurality of frames.

21. The network element of claim 1, wherein said switching matrix comprises:

a plurality of matrix element stages, and

a connection stage coupled between

a first matrix element stage of said plurality of matrix element stages, and

a second matrix element stage of said plurality of matrix element stages.

22. The network element of claim 1, wherein said stored topology information is based at least in part on received information encoded in said first optical carrier.

23. The network element of claim 1, wherein

said network element is configured to generate an electrical signal in response to said routing information, and

said switching matrix is configured to dynamically select said second optical carrier based at least in part on said electrical signal.

24. A network element comprising:

a switching matrix, wherein

said network element is configured to

receive a first optical carrier, and

transmit a first plurality of optical carriers, and

said switching matrix is configured to

dynamically select a second optical carrier of said first plurality of optical carriers based at least in part on routing information, wherein said routing information is derived at least in part from stored topology information stored in a computer-readable storage element within said network element, and

said switching matrix comprises a re-arrangeably non-blocking switching matrix comprising

a plurality of matrix element stages, and

a connection stage coupled between

a first matrix element stage of said plurality of matrix element stages, and

a second matrix element stage of said plurality of matrix element stages.

25. A method comprising:

dynamically selecting a first optical carrier of a first plurality of optical carriers by configuring a switching matrix of a network element, wherein

said configuring is based at least in part on routing information,

said routing information is derived at least in part from stored topology information stored in a computer-readable storage element within said network element, and

said stored topology information is based at least in part on information encoded in said first optical carrier; and

transmitting said first optical carrier in response to said dynamically selecting.

26. The method of claim 25, wherein said network element comprises a receiver and a transmitter, said method further comprising:

receiving a second optical carrier using said receiver;

selecting said transmitter using said routing information; and

transmitting said first optical carrier using said transmitter in response to said selecting.

27. The method of claim 26, wherein

said network element comprises a plurality of transmitters, and

said selecting comprises selecting said transmitter from said plurality of transmitters.

28. The method of claim 26, wherein

said network element comprises a signal path and a control path,

said signal path runs through said switching matrix;

and

said configuring comprises configuring said switching matrix using said control path.

29. The method of claim 28, wherein said receiver comprises a plurality of input channels, said method further comprising:

selecting a working channel from said plurality of input channels.

30. The method of claim 29, wherein said receiving said second optical carrier comprises:

receiving a second plurality of optical carriers including said second optical carrier, and

selecting said second optical carrier from said second plurality of optical carriers.

31. The method of claim 29, further comprising obtaining said routing information at said network element.

32. The method of claim 31, wherein said obtaining comprises:

sending a message from said network element to at least one other of a plurality of network elements, wherein

said message causes said at least one other of said plurality of network elements to send a response message to said network element, and

receiving said response message from said at least one other of said plurality of network elements, wherein

said response message comprises received topology information stored on said at least one other of said plurality of network elements.

33. The method of claim 32, wherein

said sending said message and said receiving said response message comprise using in-band communications.

34. The method of claim 26, wherein said second optical carrier comprises information, said method further comprising:

transferring said information from said receiver to said transmitter.

35. The method of claim 25, further comprising:

responding with a negative acknowledgement to a request encoded on said first optical carrier if output links of said network element lack sufficient bandwidth to satisfy said request.

36. An apparatus comprising:

means for dynamically selecting a first optical carrier of a first plurality of optical carriers, said means for dynamically selecting comprising

means for configuring a switching matrix of a network element based at least in part on routing information, wherein

said routing information is derived at least in part from stored topology information stored in a computer-readable storage element within said network element, and

said stored topology information is based at least in part on information encoded in said first optical carrier; and

means for transmitting said first optical carrier.

37. The apparatus of claim 36, wherein said network element comprises a receiver and a transmitter, said apparatus further comprising:

means for receiving a second optical carrier using said receiver;

means for selecting said transmitter using said routing information; and

means for transmitting said first optical carrier using said transmitter.

38. The apparatus of claim 37, wherein

said network element comprises a plurality of transmitters, and

said means for selecting comprises means for selecting said transmitter from said plurality of transmitters.

39. The apparatus of claim 37, wherein

said network element comprises a signal path and a control path,

said signal path runs through said switching matrix;

and

said means for configuring comprises means for configuring said switching matrix using said control path.

40. The apparatus of claim 37, wherein said means for receiving said second optical carrier comprises:

means for receiving a second plurality of optical carriers including said second optical carrier, and

means for selecting said second optical carrier from said second plurality of optical carriers.

41. The apparatus of claim 37, wherein said second optical carrier comprises information, said apparatus further comprising:

means for transferring said information from said receiver to said transmitter.

42. The apparatus of claim 36, further comprising means for obtaining said routing information at said network element.

43. The apparatus of claim 42, wherein said means for obtaining comprises:

means for sending a message from said network element to at least one other of a plurality of network elements, wherein

said message causes said at least one other of said plurality of network elements to send a response message to said network element, and

means for receiving said response message from said at least one other of said plurality of network elements, wherein

said response message comprises received topology information stored on said at least one other of said plurality of network elements.

44. The apparatus of claim 43, wherein

said means for sending said message and said means for receiving said response message comprise means for using in-band communications.

45. A machine-readable medium having a plurality of instructions executable by a machine embodied therein, wherein said plurality of instructions when executed cause said machine to perform a method comprising:

dynamically selecting a first optical carrier of a first plurality of optical carriers by configuring a switching matrix of a network element, wherein

said configuring is based at least in part on routing information, wherein

said routing information is derived at least in part from stored topology information stored in a computer-readable storage element within said network element, and

said stored topology information is based at least in part on information encoded in said first optical carrier; and

transmitting said first optical carrier in response to said dynamically selecting.

46. The machine-readable medium of claim 45, wherein said network element comprises a receiver and a transmitter, said method further comprising:

receiving a second optical carrier using said receiver;

selecting said transmitter using said routing information; and

transmitting said first optical carrier using said transmitter in response to said selecting.

47. The machine-readable medium of claim 46, wherein

said network element comprises a plurality of transmitters, and

said selecting comprises selecting said transmitter from said plurality of transmitters.

48. The machine-readable medium of claim 46, wherein

said network element comprises a signal path and a control path,

said signal path runs through said switching matrix;

and

said configuring comprises configuring said switching matrix using said control path.

49. The machine-readable medium of claim 48, wherein said receiver comprises a plurality of input channels, said method further comprising:

selecting a working channel from said plurality of input channels.

50. The machine-readable medium of claim 49, wherein said receiving said second optical carrier comprises:

receiving a second plurality of optical carriers including said second optical carrier, and

selecting said second optical carrier from said second plurality of optical carriers.

51. The machine-readable medium of claim 49, said method further comprising obtaining said routing information at said network element.

52. The machine-readable medium of claim 51, wherein said obtaining comprises:

sending a message from said network element to at least one other of a plurality of network elements, wherein

said message causes said at least one other of said plurality of network elements to send a response message to said network element, and

receiving said response message from said at least one other of said plurality of network elements, wherein

said response message comprises received topology information stored on said at least one other of said plurality of network elements.

53. The machine-readable medium of claim 52, wherein

said sending said message and said receiving said response message comprise using in-band communications.

54. The machine-readable medium of claim 46, wherein said second optical carrier comprises information, said method further comprising:

transferring said information from said receiver to said transmitter.