System for cross-connecting high speed digital signals

• US 5,040,170 A
• Filed: 12/09/1988
• Issued: 08/13/1991
• Est. Priority Date: 12/09/1988
• Status: Expired due to Term

• Current Assignee: Transwitch Corporation
• Original Assignee: Transwitch Corporation
• Inventors: Upp, Daniel C., Cochran, William T.
• Primary Examiner(s): Olms, Douglas W.
• Assistant Examiner(s): Marcelo, Melvin
• Application Number:
  US07/283,171
• Time in Patent Office: 977 Days
• Field of Search: 370/4, 370/84, 370/99, 370/58.1, 370/79
• US Class Current: 398/50
• CPC Class Codes: G06F 2205/123 Contention resolution, i.e. resolving conflicts between simultaneous read and write operations
• CPC Class Codes: H04J 3/1611 Synchronous digital hierarchy [SDH] or SONET H04J3/1664 takes precedence for interactions with OTN

Abstract

A modular, expandable, non-blocking system for cross-connecting high speed digital signals is provided. The system is capable of connecting DSn, CEPTn, and STSn signals as desired, with lower rate signals being included as components of the high-rate signals or terminating on low speed lines, as desired. The system accomplishes its goals by converting all incoming signals into a substantially SONET format, and by processing all the signals in that format. The signals are typically cross-connected in the substantially SONET format, although an expandable non-blocking wide band cross-connect module is provided which cross-connects any like signals. If the outgoing signal is to be in other than SONET format, the substantially SONET formatted signal is reconverted into its outgoing format. To create a complete system, various modules are utilized, including: add/drop multiplexer means for add/drop applications of DS-0, DS-1, CEPTn signals, etc.; a SONET bus interface; a virtual tributary cross-connect module which cross-connects virtual tributary payloads in space, time, and phase to generate new substantially SONET formatted signals; a wide band cross-connect module; a DS-3/SONET converter; and front end interfaces including a DS3 line interface, and various STSn interfaces. The modules may be mixed and matched as desired to accommodate a multitude of applications.

Claims

1. A modular, expandible cross-connect system for high speed digital signals, comprising:

(a) receiving means for receiving at least one signal formatted in other than a substantially SONET format;

(b) converting means coupled to said receiving means for converting into a substantially SONET formatted signal said at least one signal received by said receiving means; and

(c) cross-connection means coupled to said converting means for cross-connecting said substantially SONET formatted signal.

2. A system according to claim 1, wherein:

said converting means comprises means for receiving one of a DSn and CEPTn formatted signal, means for converting said one of a DSn and CEPTn signal into at least a part of a virtual tributary format signal, and means for placing said at least a part of a virtual tributary format signal in an appropriate time frame on a substantially SONET formatted bus such that said at least a part of a virtual tributary format signal is part of a substantially SONET formatted signal.

3. A system according to claim 2, wherein:

said cross-connection means comprises at least a virtual tributary cross-connection means, said virtual tributary cross-connection means comprising,

SONET signal receiving means for receiving a plurality of substantially SONET formatted signals, including means for disassembling said substantially SONET formatted signals into virtual tributary payloads of tracked phase, and

means for cross-connecting said virtual tributary payloads in space, time, and phase to generate new substantially SONET formatted signals.

4. A system according to claim 3, further comprising:

(d) transmitting means coupled to said virtual tributary cross-connection means and coupled to one of DSn, CEPTn, and STSn compatible transmission lines for transmitting a cross-connected substantially SONET formatted signal over one of said DSn, CEPTn, and STSn compatible transmission lines.

5. A system according to claim 4, wherein:

said transmitting means is coupled to an STS-1 line and comprises a SONET path terminating means coupled to said virtual tributary cross-connection means for receiving a substantially SONET formatted signal, for creating a bit serial SONET formatted signal output therefrom by inserting at least path and transport overhead information in said substantially SONET signal, and for providing line interface functions to permit said bit serial SONET formatted signal to be transmitted on said STS-1 line.

6. A system according to claim 4, wherein:

said transmitting means is coupled to an STSn line, where n is greater than one, and said transmitting means comprises

a SONET path terminating means coupled to said virtual tributary cross-connection means for receiving a substantially SONET formatted signal, for creating a SONET formatted signal therefrom by inserting at least path and transport overhead information in said substantially SONET signal, and

a multiplexer means for receiving and multiplexing at least two of said SONET signals from a plurality of said SONET path terminating means to create a bit serial STSn formatted output signal where n is greater than one, and for providing line interface functions to permit said bit serial STSn formatted signal to be transmitted on said STSn line.

7. A system according to claim 4, wherein:

said transmitting means is coupled to an STSn line, where n is greater than three, and said transmitting means comprises

a SONET path terminating means coupled to said virtual tributary cross-connection means for receiving a substantially SONET formatted signal, for creating a SONET formatted signal therefrom by inserting at least path and transport overhead information in said substantially SONET signal,

a first multiplexer means for receiving and multiplexing at least three of said SONET signals from a plurality of said SONET path terminating means to create a first STSn formatted signal where n is greater than one,

a second multiplexer means for receiving, multiplexing, and scrambling a plurality of said first STSn formatted signals to create a second STSn formatted signal where n is greater than three, and

a line interface means for receiving said second STSn formatted signal, for providing a second bit serial STSn formatted signal therefrom, where n is greater than three, and for interfacing said second STSn formatted signal to said STSn line of same bit rate.

8. A system according to claim 4, wherein:

said transmitting means is coupled to one of said DSn and CEPTn compatible transmission lines, and comprises means for extracting at least one virtual tributary, from a substantially SONET formatted signal, and second converting means for converting said at least one virtual tributary into one of a DSn and CEPTn format for transmitttal over said one of DSn and CEPTn compatible transmission lines.

9. A system according to claim 8, wherein:

said transmitting means is coupled to a DS-3 compatible transmission line, said means for extracting extracts twenty-eight virtual tributaries from said substantially SONET formatted signal, said second converting means comprises means for stuffing said twenty-eight virtual tributaries into twenty-eight DS-1 formatted signals and means for building a substantially DS-3 formatted signals from said twenty-eight DS-1 formatted signals.

10. A system according to claim 8, wherein:

said transmitting means is coupled to an asynchronous DS-1 compatible transmission line, and said second means for converting converts each extracted virtual tributary into an asynchronous DS-1 compatible signal at a like rate to a DS-1 compatible transmission line to which it is coupled.

11. A system according to claim 8, wherein:

said transmission means is coupled to a synchronous DS-1 compatible transmission line, and said second means for converting converts each extracted virtual tributary into a synchronous DS-1 compatible signal at a like rate to a DS-1 compatible transmission line to which it is coupled.

12. A system according to claim 8, wherein:

said transmitting means is coupled to an asynchronous CEPTn compatible transmission line, and said second means for converting converts each extracted virtual tributary into an asynchronous CEPTn compatible signal at a like rate to a CEPTn compatible transmission line to which it is coupled.

13. A system according to claim 8, wherein:

said transmitting means is coupled to a synchronous CEPTn compatible transmission line, and said second means for converting converts each extracted virtual tributary into a synchronous CEPTn compatible signal at a like rate to a CEPTn compatible transmission line to which it is coupled.

14. A system according to claim 11, wherein:

said means for receiving one of a DSn and CEPTn formatted signal comprises means for receiving a synchronous DS-1 formatted signal, said means for converting comprises means for converting said synchronous DS-1 formatted signal into a virtual tributary format signal.

15. A system according to claim 4, wherein:

at least a portion of said substantially SONET formatted signal is synchronous, and

said transmitting means is coupled to a DS-0 compatible interface and comprises means for extracting at least a predefined part of a virtual tributary of said synchronous substantially SONET formatted signal, and second converting means for converting said predefined part of said virtual tributary into a DS-0 format for transmittal over said DS-0 interface.

16. A system according to claim 15, wherein:

said means for receiving comprises means for receiving a synchronous DS-0 formatted signal, said means for converting comprises means for converting said synchronous DS-0 formatted signal into said portion of a virtual tributary format signal.

17. A system according to claim 11, wherein:

said means for receiving comprises means for receiving a synchronous DS-0 formatted signal, said means for converting comprises means for converting said synchronous DS-0 formatted signal into a part of a virtual tributary format signal.

18. A system according to claim 4, further comprising:

(e) said substantially SONET formatted bus coupled to said transmitting means, wherein said substantially SONET formatted bus transports said substantially formatted SONET signal in byte-parallel fashion in conjunction with at least an associated clock, and said converting means includes serial-parallel data conversion means for receiving data in a serial format and providing a parallel format representation thereof.

19. A system according to claim 18, further comprising:

non-blocking wide band cross-connecting means including a plurality of data ports and a plurality of associated clock ports, and means for cross-connecting at least said substantially SONET formatted signals received at a first data port along with an associated clock signal received at an associated clock port to respective any of said plurality of data ports and associated clock ports, wherein at least a first group of said plurality of data ports and associated clock ports are coupled to said receiving means, and at least a second group of said plurality of data ports and associated clock ports are coupled to said transmitting means.

20. A system according to claim 2, wherein:

said cross-connection means comprises at least said substantially SONET formatted bus coupled to said means for placing said converting means, wherein said substantially SONET formatted bus transports said substantially formatted SONET signal in byte-parallel fashion in conjunction with at least an associated clock, and said converting means includes serial-parallel data conversion means for receiving data in a serial format and providing a parallel format representation thereof.

21. A system according to claim 20, further comprising:

(d) transmitting means coupled to said substantially SONET formatted bus, and further coupled to one of a DSn, CEPTn and STSn compatible transmission lines for transmitting a cross-connected substantially SONET formatted signal over one of said DSn, CEPTn, and STSn compatible transmission lines.

22. A system according to claim 21, wherein:

said transmitting means is coupled to an STS-1 line and comprises a SONET path terminating means coupled to said substantially SONET formatted bus for receiving a substantially SONET formatted signal, for creating a bit serial SONET formatted signal output therefrom by inserting at least path and transport overhead information in said substantially SONET signal, and for providing line interface functions to permit said bit serial SONET formatted signal to be transmitted on said STS-1 line.

23. A system according to claim 21, wherein:

said transmitting means is coupled to an STSn line, where n is greater than one, and said transmitting means comprises

a SONET path terminating means coupled to said substantially SONET formatted bus for receiving a substantially SONET formatted signal, for creating a SONET formatted signal therefrom by inserting at least path and transport overhead information in said substantially SONET signal, and

a multiplexer means for receiving and multiplexing at least two of said SONET signals from a plurality of said SONET path terminating means to create a bit serial STSn formatted output signal where n is greater than one, and for providing line interface functions to permit said bit serial STSn formatted signal to be transmitted on said STSn line.

24. A system according to claim 21, wherein:

said transmitting means is coupled to an STSn like, where n is greater than three, and said transmitting means comprises

a SONET path terminating means coupled to said substantially SONET formatted bus for receiving a substantially SONET formatted signal, for creating a SONET formatted signal therefrom by inserting at least path and transport overhead information in said substantially SONET signal,

a first multiplexer means for receiving and multiplexing at least three of said SONET signals from a plurality of said SONET path terminating means to create a first STSn formatted signal where n is greater than one.

a second multiplexer means for receiving, multiplexing, and scrambling a plurality of said first STSn formatted signals to create a second STSn formatted signal where n is greater than three, and

a line interface means for receiving said second STSn formatted signal, for providing a second bit serial STSn formatted signal therefrom, where n is greater than three, and for interfacing said second STSn formatted signal to said STSn line of same bit rate.

25. A system according to claim 21, wherein,

said transmitting means is coupled to a DS-3 compatible transmission line, and comprises means for extracting twenty-eight virtual tributaries from said substantially SONET formatted signal, and second converting means for converting said twenty-eight virtual tributaries into a substantially DS-3 formatted signal, said second converting means comprising means for stuffing said twenty-eight virtual tributaries into twenty-eight DS-1 formatted signals and means for building a substantially DS-3 formatted signal from said twenty-eight DS-1 formatted signals.

26. A system according to claim 21, further comprising:

non-blocking wide band cross-connecting means including a plurality of data ports and a plurality of associated clock ports, and means for cross-connecting at least said substantially SONET formatted signals received at a first data port along with an associated clock signal received at an associated clock port to respective any of said plurality of data ports and associated clock ports, wherein at least a first group of said plurality of data ports and associated clock ports are coupled to said receiving means, and at least a second group of said plurality of data ports and associated clock ports are coupled to said transmitting means.

27. A system according to claim 1, wherein:

said converting means comprises means for receiving a DS-3 formatted signal, means for demultiplexing said DS-3 signal into at least twenty-eight constituent DS-1 signals, means for stuffing said DS-1 signals into twenty-eight virtual tributaries, and means for providing overhead signals, to create therefrom a substantially SONET formatted signal.

28. A system according to claim 27, wherein:

said cross-connection means comprises at least a virtual tributary cross-connection means, said virtual tributary cross-connection means comprising,

SONET signal receiving means for receiving a plurality of substantially SONET formatted signals, including means for disassembling said substantially SONET formatted signals into virtual tributary payloads of tracked phase, and

means for cross-connecting said virtual tributary payloads in space, time, and phase to generate new substantially SONET formatted signals.

29. A system according to claim 28, further comprising:

(d) transmitting means coupled to said virtual tributary cross-connection means and coupled to one of DSn, CEPTn, and STSn compatible transmission lines for transmitting a cross-connected substantially SONET formatted signal over one of said DSn, CEPTn, and STSn compatible transmission lines.

30. A system according to claim 29, wherein:

said transmitting means is coupled to an STS-1 line and comprises a SONET path terminating means coupled to said virtual tributary cross-connection means for receiving a substantially SONET formatted signal, for creating a bit serial SONET formatted signal output therefrom by inserting at least path and transport overhead information in said substantially SONET signal, and for providing line interface functions to permit said bit serial SONET formatted signal to be transmitted on said STS-1 line.

31. A system according to claim 29, wherein:

said transmitting means is coupled to an STSn line, where n is greater than one, and said transmitting means comprises

a SONET path terminating means coupled to said virtual tributary cross-connection means for receiving a substantially SONET formatted signal, for creating a SONET formatted signal therefrom by inserting at least path and transport overhead information in said substantially SONET signal, and

a multiplexer means for receiving and multiplexing at least two of said SONET signals from a plurality of said SONET path terminating means to create a bit serial STSn formatted output signal where n is greater than one, and for providing line interface functions to permit said bit serial STSn formatted signal to be transmitted on said STSn line.

32. A system according to claim 29, wherein:

said transmitting means is coupled to an STSn line, where n is greater than three, and said transmitting means comprises

a SONET path terminating means coupled to said virtual tributary cross-connection means for receiving a substantially SONET formatted signal, for creating a SONET formatted signal therefrom by inserting at least path and transport overhead information in said substantially SONET signal,

a first multiplexer means for receiving and mutiplexing at least three of said SONET signals from a plurality of said SONET path terminating means to create a first STSn formatted signal where n is greater than one,

a second multiplexer means for receiving, multiplexing, and scrambling a plurality of said first STSn formatted signals to create a second STSn formatted signal where n is greater than three, and

a line interface means for receiving said second STSn formatted signal, for providing a second bit serial STSn formatted signal therefrom, where n is greater than three, and for interfacing said second STSn formatted signal to said STSn line of same bit rate.

33. A system according to claim 29, wherein:

said transmitting means is coupled to an asynchronous DS-1 compatible transmission line and to a substantially SONET formatted bus, said transmitting means comprising means for extracting at least one virtual tributary from said substantially SONET formatted bus, and second means for converting converts each extracted virtual tributary into an asynchronous DS-1 compatible signal at a like rate to a DS-1 compatible transmission line to which it is coupled.

34. A system according to claim 33, further comprising:

(e) said substantially SONET formatted bus coupled to said transmitting means, wherein said substantially SONET formatted bus transports said substantially formatted SONET signal in byte-parallel fashion in conjunction with at least an associated clock, and said transmitting means includes parallel-serial data conversion means for receiving data in a parallel format and providing a serial format representation thereof.

35. A system according to claim 29, further comprising:

non-blocking wide band cross-connecting means including a plurality of data ports and a plurality of associated clock ports, and means for cross-connecting at least said substantially SONET formatted signals received at a first data port along with an associated clock signal received at an associated clock port to respective any of said plurality of data ports and associated clock ports, wherein at least a first group of said plurality of data ports and associated clock ports are coupled to said receiving means, and at least a second group of said plurality of data ports and associated clock ports are coupled to said transmitting means.

36. A system according to claim 27, further comprising:

(d) transmitting means coupled to an asynchronous DS-1 compatible transmission line and to a substantially SONET formatted bus, said transmitting means comprising means for extracting at least one virtual tributary from said substantially SONET formatted bus, and second means for converting each extracted virtual tributary into an asynchronous DS-1 compatible signal at a like rate to a DS-1 compatible transmission line to which it is coupled, wherein

said cross-connection means comprises said substantially SONET formatted bus, said substantially SONET formatted bus further coupled to said converting means which supplies a substantially SONET formatted signal.

37. A system according to claim 36, further comprising:

non-blocking wide band cross-connecting means including a plurality of data ports and a plurality of associated clock ports, and means for cross-connecting at least said substantially SONET formatted signals received at a first data port along with an associated clock signal received at an associated clock port to respective any of said plurality of data ports and associated clock ports, wherein at least a first of said plurality of data ports and an associated clock port are coupled to said receiving means, and at least a second of said plurality of data ports and an associated clock ports are coupled to said transmitting means.

38. A modular, expandible cross-connect system for high speed digital signals, comprising:

(a) receiving means for receiving at least one substantially SONET formatted signal;

(b) cross-connection means coupled to said receiving for cross-connecting said received signal; and

(c) converting means coupled to said cross-connection means for converting into a format other than a substantially SONET formatted signal said cross-connected substantially SONET formatted signal.

39. A system according to claim 38, wherein:

said cross-connection means comprises at least a virtual tributary cross-connection means, said virtual tributary cross-connection means comprising,

SONET signal receiving means for receiving a plurality of substantially SONET formatted signals, including means for disassembling said substantially SONET formatted signals into virtual tributary payloads of tracked phase, and

means for cross-connecting said virtual tributary payloads in space, time, and phase to generate new substantially SONET formatted signals.

40. A system according to claim 39, further comprising:

(d) transmitting means for transmitting said cross-connected converted signal over one of a DSn and CEPTn compatible transmission line, wherein,

said converting means comprises means for extracting at least part of one virtual tributary form said substantially SONET formatted signal, and for converting said at least part of one virtual tributary into one of a DSn and CEPTn signal.

41. A system according to claim 40, wherein:

said transmitting means is coupled to a DS-3 compatible transmission line, said means for extracting extracts twenty-eight virtual tributaries from said substantially SONET formatted signal, and said means for converting further comprises means for stuffing said twenty-eight virtual tributaries into twenty-eight DS-1 formatted signals and means for building a substantially DS-3 formatted signal from said twenty-eight DS-1 formatted signals.

42. A system according to claim 40, wherein:

said transmitting means is coupled to an asynchronous DS-1 compatible transmission line, and said means for converting converts each extracted virtual tributary into an asynchronous DS-1 compatible signal at a like rate to a DS-1 compatible transmission line to which it is coupled.

43. A system according to claim 40, wherein:

said transmitting means is coupled to a synchronous DS-1 compatible transmission line, and said means for converting converts each extracted virtual tributary into a synchronous DS-1 compatible signal at a like rate to a DS-1 compatible transmission line to which it is coupled.

44. A system according to claim 40, wherein:

said transmitting means is coupled to an asynchronous CEPTn compatible transmission line, and said means for converting converts each extracted virtual tributary into an asynchronous CEPTn compatible signal at a like rate to a CEPTn compatible transmission line to which it is coupled.

45. A system according to claim 40, wherein:

said transmitting means is coupled to a synchronous CEPTn compatible transmission line, and said means for converting converts each extracted virtual tributary into a synchronous CEPTn compatible signal at a like rate to a CEPTn compatible transmission line to which it is coupled.

46. A system according to claim 40, wherein:

at least a portion of said substantially SONET formatted signal is synchronous, and

said transmitting means is coupled to a DS-0 compatible interface, said means for extracting extracts at least a predefined part of a virtual tributary of said synchronous substantially SONET formatted signal, and said converting means converts said predefined part of said virtual tributary into a DS-0 format for transmittal over said DS-0 interface.

47. A system according to claim 41, wherein:

said receiving means is coupled to an STS-1 line and comprises a SONET path terminating means for interfacing said STS-1 line and said system, said SONET path terminating means being further coupled to said virtual tributary cross-connection means.

48. A system according to claim 41, wherein:

said receiving means is coupled to an STSn line and receives an STSn formatted signal, wherein n is greater than one, and comprises a demultiplexing means for demultiplexing said STSn signal into n SONET STS-1 signals, and at least n SONET path terminating means for providing substantially SONET formatted signals from each STS-1 signal, wherein at least one of said SONET path terminating means is coupled to said virtual tributary cross-connect means.

49. A system according to claim 41, wherein:

said receiving means is coupled to an STSn line and receives an STSn formatted signal, wherein n is greater than three, and comprises a first demultiplexing means for descrambling and demultiplexing said STSn signal into a plurality of unscrambled composite parts, a second demultiplexing means for demultiplexing said unscrambled composite parts into n STS-1 formatted signals, and at least n SONET path terminating means for providing substantially SONET formatted signals from each STS-1 signal, wherein at least one of said SONET path terminating means is coupled to said virtual tributary cross-connect means.

50. A system according to claim 42, wherein:

said receiving means is coupled to an STS-1 line and comprises a SONET path terminating means for interfacing said STS-1 line and said system, said SONET path terminating means being further coupled to said virtual tributary cross-connection means.

51. A system according to claim 42, wherein:

said receiving means is coupled to an STSn line and receives an STSn formatted signal, wherein n is greater than one, and comprises a demultiplexing means for demultiplexing said STSn signal into n SONET STS-1 signals, and at least n SONET path terminating means for providing substantially SONET formatted signals from each STS-1 signal, wherein at least one of said SONET path terminating means is coupled to said virtual tributary cross-connect means.

52. A system according to claim 42, wherein:

said receiving means is coupled to an STSn line and receives an STSn formatted signal, wherein n is greater than three, and comprises a first demultiplexing means for descrambling and demultiplexing said STSn signal into a plurality of unscrambled composite parts, a second demultiplexing means for demultiplexing said unscrambled composite parts into n STS-1 formatted signals, and at least n SONET path terminating means for providing substantially SONET formatted signals from each STS-1 signal, wherein at least one of said SONET path terminating means is coupled to said virtual tributary cross-connect means.

53. A system according to claim 43, wherein:

said receiving means is coupled to an STS-1 line and comprises a SONET path terminating means for interfacing said STS-1 line and said system, said SONET path terminating means being further coupled to said virtual tributary cross-connection means.

54. A system according to claim 43, wherein:

said receiving means is coupled to an STSn line and receives an STSn formatted signal, wherein n is greater than one, and comprises a demultiplexing means for demultiplexing said STSn signal into n SONET STS-1 signals, and at least n SONET path terminating means for providing substantially SONET formatted signals from each STS-1 signal, wherein at least one of said SONET path terminating means is coupled to said virtual tributary cross-connect means.

55. A system according to claim 43, wherein:

said receiving means is coupled to an STSn line and receives an STSn formatted signal, wherein n is greater than three, and comprises a first demultiplexing means for descrambling and demultiplexing said STSn signal into a plurality of unscrambled composite parts, a second demultiplexing means for demultiplexing said unscrambled composite parts into n STS-1 formatted signals, and at least n SONET path terminating means for providing substantially SONET formatted signals from each STS-1 signal, wherein at least one of said SONET path terminating means is coupled to said virtual tributary cross-connect means.

56. A system according to claim 40, further comprising:

(e) a substantially SONET formatted bus coupled to said converting and transmitting means, wherein said substantially SONET formatted bus transports said substantially formatted SONET signal in byte-parallel fashion in conjunction with at least an associated clock, and said converting means includes parallel-serial data conversion means for receiving data in a parallel format and providing a serial format representation thereof.

57. A system according to claim 56, further comprising:

non-blocking wide band cross-connecting means including a plurality of data ports and a plurality of associated clock ports, and means for cross-connecting at least said substantially SONET formatted signals received at a first data port along with an associated clock signal received at an associated clock port to respective any of said plurality of data ports and associated clock ports, wherein at least a first group of said plurality of data ports and associated clock ports are coupled to said receiving means, and at least a second group of said plurality of data ports and associated clock ports are coupled to said transmitting means.

58. A system according to claim 38, further comprising:

(d) transmitting means for transmitting said cross-connected converted signal over one of a DSn and CEPTn compatible transmission line, wherein,

said converting means comprises means for extracting at least part of one virtual tributary from said substantially SONET formatted signal, and for converting said at least part of one virtual tributary into one of a DSn and CEPTn signal, and

said cross-connection means comprises at least a substantially SONET formatted bus coupled to said converting means, wherein said substantially SONET formatted bus transports said substantially formatted SONET signal in byte-parallel fashion in conjunction with at least an associated clock, and said converting means includes parallel-serial data conversion means for receiving data in a parallel format and providing a serial format representation thereof.

59. A system according to claim 58, wherein:

said transmitting means is coupled to an asynchronous DS-1 compatible transmission line, and said means for converting converts each extracted virtual tributary into an asynchronous DS-1 compatible signal at a like rate to a DS-1 compatible transmission line to which it is coupled.

60. A system according to claim 58, wherein:

said transmitting means is coupled to a synchronous DS-1 compatible transmission line, and said means for converting converts each extracted virtual tributary into a synchronous DS-1 compatible signal at a like rate to a DS-1 compatible transmission line to which it is coupled.

61. A system according to claim 58, wherein:

said transmitting means is coupled to an asynchronous CEPTn compatible transmission line, and said means for converting converts each extracted virtual tributary into an asynchronous CEPTn compatible signal at a like rate to a CEPTn compatible transmission line to which it is coupled.

62. A system according to claim 58, wherein:

said transmitting means is coupled to a synchronous CEPTn compatible transmission line, and said means for converting converts each extracted virtual tributary into a synchronous CEPTn compatible signal at a like rate to a CEPTn compatible transmission line to which it is coupled.

63. A system according to claim 58, wherein:

at least a portion of said substantially SONET formatted signal is synchronous, and

said transmitting means is coupled to a DS-0 compatible interface, said means for extracting extracts at least a predefined part of a virtual tributary of said synchronous substantially SONET formatted signal, and said converting means converts said predefined part of said virtual tributary into a DS-0 format for transmittal over said DS-0 interface.

64. A system according to claim 58, further comprising:

non-blocking wide band cross-connecting means including a plurality of data ports and a plurality of associated clock ports, and means for cross-connecting at least said substantially SONET formatted signals received at a first data port along with an associated clock signal received at an associated clock port to respective any of said plurality of data ports and associated clock ports, wherein at least a first group of said plurality of data ports and associated clock ports are coupled to said receiving means, and at least a second group of said plurality of data ports and associated clock ports are coupled to said transmitting means.

65. A system according to claim 59, wherein:

said receiving means is coupled to an STS-1 line and comprises a SONET path terminating means for interfacing said STS-1 line and said system, said SONET path terminating means being further coupled to said virtual tributary cross-connection means.

66. A system according to claim 59, wherein:

said receiving means is coupled to an STSn line and receives an STSn formatted signal, wherein n is greater than one, and comprises a demultiplexing means for demultiplexing said STSn signal into a n SONET STS-1 signals, and at least n SONET path terminating means for providing substantially SONET formatted signals from each STS-1 signal, wherein at least one of said SONET path terminating means is coupled to said virtual tributary cross-connect means.

67. A system according to claim 59, wherein:

said receiving means is coupled to an STSn line and receives an STSn formatted signal, wherein n is greater than three, and comprises a first demultiplexing means for descrambling and demultiplexing said STSn signal into a plurality of unscrambled composite parts, a second demultiplexing means for demultiplexing said unscrambled composite parts into n STS-1 formatted signals, and at least n SONET path terminating means for providing substantially SONET formatted signals from each STS-1 signal, wherein at least one of said SONET path terminating means is coupled to said virtual tributary cross-connect means.

68. A system according to claim 60, wherein:

said receiving means is coupled to an STS-1 line and comprises a SONET path terminating means for interfacing said STS-1 line and said system, said SONET path terminating means being further coupled to said virtual tributary cross-connection means.

69. A system according to claim 60, wherein:

said receiving means is coupled to an STSn line and receives an STSn formatted signal, wherein n is greater than one, and comprises a demultiplexing means for demultiplexing said STSn signal into n SONET STS-1 signals, and at least n SONET path terminating means for providing substantially SONET formatted signals from each STS-1 signal, wherein at least one of said SONET path terminating means is coupled to said virtual tributary cross-connect means.

70. A system according to claim 60, wherein:

said receiving means is coupled to an STSn line and receives an STSn formatted signal, wherein n is greater than three, and comprises a first demultiplexing means for descrambling and demultiplexing said STSn signal into a plurality of unscrambled composite parts, a second demultiplexing means for demultiplexing said unscrambled composite parts into n STS-1 formatted signals, and at least n SONET path terminating means for providing substantially SONET formatted signals from each STS-1 signal, wherein at least one of said SONET path terminating means is coupled to said virtual tributary cross-connect means.

71. A modular, expandible cross-connect system for high speed digital signals, comprising:

(a) at least one receiving/transmitting means for receiving at least one signal formatted in other than a substantially SONET format, and for transmitting in other than a substantially SONET format at least one cross-connected signal;

(b) converting means coupled to said receiving/transmitting means for converting into a substantially SONET formatted signal said at least one signal formatted in other than a substantially SONET format received by said receiving means, and for converting into said format other than a substantially SONET format said at least one cross-connected substantially SONET formatted signal; and

(c) cross-connection means coupled to said converting means for cross-connecting said substantially SONET formatted signal.

72. A system according to claim 71, further comprising:

(d) a DS-3/SONET converting means including

means for extracting twenty-eight virtual tributaries from a substantially SONET formatted signal, means for stuffing said twenty-eight virtual tributaries into twenty-eight DS-1 formatted signals, and means for building a substantially DS-3 formatted signal from said twenty-eight DS-1 formatted signals, and

means for receiving a DS-3 formatted signal, means for demultiplexing said DS-3 signal into at least twenty-eight constituent DS-1 signals, means for stuffing said DS-1 signals into twenty-eight virtual tributaries, and means for providing overhead signals, to create therefrom a substantially SONET formatted signal, wherein

said DS-3/SONET converting means is coupled to said cross-connection means.

73. A system according to claim 72, further comprising:

(e) SONET path origination/termination means for

receiving a substantially SONET formatted signal, creating a bit serial SONET formatted signal output therefrom by inserting at least path and transport overhead information in said substantially SONET signal, and providing line interface functions to permit said bit serial SONET formatted signal to be transmitted on an STSn line, and for

receiving a SONET formatted signal from an STSn line and interfacing said STSn line and said system.

74. A system according to claim 73, wherein:

said cross-connection means comprises a virtual tributary cross-connection means, said virtual tributary cross-connection means comprising,

SONET signal receiving means for receiving a plurality of substantially SONET formatted signals, including means for disassembling said substantially SONET formatted signals into virtual tributary payloads of tracked phase, and

means for cross-connecting said virtual tributary payloads in space, time, and phase to generate new substantially SONET formatted signals.

75. A system according to claim 74, further comprising:

(f) a substantially SONET formatted bus coupled to at least said receiving/transmitting means, wherein said substantially SONET formatted bus transports said substantially formatted SONET signal in byte-parallel fashion in conjunction with at least an associated clock to and from said receiving/transmitting means, and said receiving means includes serial-parallel data conversion means for receiving data in a serial format and providing a parallel format representation thereof with an associated clock, and said transmitting means includes parallel-serial data conversion means for receiving data in a parallel format with an associated clock and providing a serial format representation thereof.

76. A system according to claim 75, wherein:

said receiving/transmitting means and said converting means together comprise an add/drop multiplexer means.

77. A system according to claim 76, wherein:

a plurality of receiving/transmitting means and converting means are provided and comprise at least a plurality of said add/drop multiplexer means, each add/drop multiplexer means having said receiving/transmitting means for receiving one of a DSn and CEPTn formatted signal, said converting means for converting said one of a DSn and CEPTn signal into at least a part of a virtual tributary format signal, and means for placing said at least a part of a virtual tributary format signal in an appropriate time frame on said substantially SONET formatted bus such that said at least a part of a virtual tributary format signal is part of a substantially SONET formatted signal.

78. A system according to claim 77, wherein:

said plurality of add/drop multiplexer means comprise

an asynchronous DS-1 add/drop multiplexer for receiving an asynchronous DS-1 formatted signal, for converting said asynchronous DS-1 signal into an asynchronous virtual tributary format signal, and for inserting said asynchronous virtual tributary format signal onto said substantially SONET formatted bus at appropriate times,

a synchronous DS-1 add/drop multiplexer for receiving a synchronous DS-1 formatted signal, for converting said DS-1 signal into a synchronous virtual tributary format signal, and for inserting said asynchronous virtual tributary format signal onto said substantially SONET formatted bus at appropriate times.

79. A system according to claim 78, wherein:

said plurality of add/drop multiplexer means further comprise

a synchronous DS-0 add/drop multiplexer for receiving a DS-0 formatted signal, for converting said DS-0 signal into a part of a synchronous virtual tributary format signal, and for inserting said part of a synchronous virtual tributary format signal onto said substantially SONET formatted bus at appropriate times.

80. A system according to claim 79, wherein:

said plurality of add/drop multiplexer means further comprise

a synchronous and an asynchronous CEPTn add/drop multiplexers for respectively receiving synchronous and asynchronous CEPTn formatted signals, for respectively converting said synchronous and asynchronous CEPTn into virtual tributary format signals, and for respectively inserting said virtual tributary format signals onto said substantially SONET formatted bus at appropriate times

81. A system according to claim 77, further comprising:

(g) non-blocking wide band cross-connecting means including a plurality of data ports and a plurality of associated clock ports, and means for cross-connecting at least said substantially SONET formatted signals received at a first data port along with an associated clock signal received at an associated clock port to respective any of said plurality of data ports and associated clock ports, wherein at least a first group of said plurality of data ports and associated clock ports are coupled to said receiving means, and at least a second group of said plurality of data ports and associated clock ports are coupled to said transmitting means.