Layer one switching in a packet, cell, or frame-based network

• US 6,611,519 B1
• Filed: 08/16/1999
• Issued: 08/26/2003
• Est. Priority Date: 08/19/1998
• Status: Expired due to Fees

• Current Assignee: Swxtch The Rules, LLC
• Original Assignee: Swxtch The Rules, LLC
• Inventors: Howe, Wayne R.
• Primary Examiner(s): Ton, Dang
• Assistant Examiner(s): Duong, Frank
• Application Number:
  US09/375,135
• Time in Patent Office: 1,471 Days
• Field of Search: 370/428, 370/230, 370/231, 370/235, 370/360, 370/386, 370/395.4, 370/395.62, 370/395.21, 370/465, 370/468, 370/413
• US Class Current: 370/386
• CPC Class Codes: H04J 3/0644 External master-clock
• CPC Class Codes: H04J 3/0667 Bidirectional timestamps, e.g. NTP or PTP for compensation of clock drift and for compensation of propagation delays arrangements for monitoring round trip delays in packet switching networks H04L43/0864
• CPC Class Codes: H04L 12/5601 Transfer mode dependent, e.g. ATM
• CPC Class Codes: H04L 47/2416 Real-time traffic
• CPC Class Codes: H04L 49/251 Cut-through or wormhole routing
• CPC Class Codes: H04L 49/254 Centralised controller, i.e. arbitration or scheduling
• CPC Class Codes: H04L 49/3009 Header conversion, routing tables or routing tags
• CPC Class Codes: H04L 49/3018 Input queuing
• CPC Class Codes: H04L 49/3027 Output queuing
• CPC Class Codes: H04L 49/602 Multilayer or multiprotocol switching, e.g. IP switching

Abstract

A system and method are described for synchronizing store-and-forward networks and for scheduling and transmitting continuous, periodic, predictable, time-sensitive, or urgent information such as real-time and high-priority messages over those networks. This enables packet-, cell-, and/or frame-based networks to thereby efficiently switch voice, video, streaming, and other real-time or high-priority data at the layer one or physical level, thus ensuring that the delivery of selected information can be made fast, on-time, immediate, non-blocked, non-congested, loss-less, jitter-free, and have guaranteed delivery, and guaranteed quality of service.

Claims

1. A method for switching information through one or more of network elements, comprising the steps of:

associating a synchronization component with each of said one or more of network elements;

synchronizing said synchronization component in each of said one or more of network elements;

establishing a reservation schedule in each of said one or more of network elements;

opening in each of said one or more of network elements a layer one connection at a predicted time in accordance with said reservation schedule;

transmitting information from a source network element to a destination network element through said layer one connection in each of said one or more of network elements in accordance with said reservation schedule; and

closing said layer one connection in each of said one or more of network elements.

2. The method of claim 1 wherein said information comprises data selected from the group consisting of real-time data, high-priority data, and time sensitive data.

3. The method of claim 1 wherein said information comprises data selected from the group consisting of cell-oriented, frame-oriented, and packet-oriented data.

4. The method of claim 1 wherein said synchronization component associated with each of said network elements is a clock.

5. The method of claim 4 wherein said clock associated with each of said network elements is synchronized in accordance with a master clock.

6. The method of claim 5 wherein said master clock is the Global Positioning System.

7. The method of claim 1 wherein each of said one or more of network elements is a store-and-forward network element.

8. The method of claim 1 further comprising the step of resetting said reservation schedule in at least two of said network elements.

9. The method of claim 8 wherein the step of resetting said reservation schedule is initiated by a mid-destination network element.

10. The method of claim 8 wherein the step of resetting said reservation schedule is initiated by a final destination network element.

11. A network element for routing of data comprising:

a store-and-forward switching component for transmission of store-and-forward data;

bypass switching circuitry for transmission of data;

a clock;

a scheduler for scheduling transmissions of data at previously known times in conjunction with said bypass switching circuitry; and

a controller for monitoring said clock and said scheduler, said controller adapted to activate said bypass switching circuitry in accordance with said scheduler and said clock.

12. The network element of claim 11 wherein said store-and-forward switching component is integrated in said network element.

13. The network element of claim 11 wherein said store-and-forward switching component is independent of said network element.

14. The network element of claim 11 wherein said bypass switching circuitry is overlaid around said store-and-forward switching component.

15. The network element of claim 11 wherein said bypass switching circuitry comprises layer one switching circuitry.

16. The network element of claim 11 further comprising buffers for holding said data in conjunction with said bypass switching circuitry.

17. The network element of claim 11 wherein said data comprises headerless data.

18. The network element of claim 11 wherein said data is selected from the group consisting of cell-oriented data, frame-oriented data, packet-oriented data, time sensitive data, and time insensitive data.

19. The network element of claim 11 wherein said store-and-forward data comprises data selected from the group consisting of cell-oriented data, frame-oriented data, packet-oriented data, time sensitive data, and time insensitive data.

20. A device for switching comprising:

layer one switching circuitry;

a clock;

a scheduler for scheduling previously derived times for layer one switching circuitry; and

a controller for monitoring said clock and said scheduler, said controller adapted to activate said layer one switching circuitry in accordance with said scheduler and said clock.

21. The device of claim 20 wherein said layer one switching circuitry is adapted for transmission of real-time data.

22. The device of claim 20 further comprising store-and-forward switching circuitry.

23. The device of claim 22 wherein said store-and-forward switching circuitry is integrated in said network element.

24. The device of claim 22 wherein said layer one switching circuitry is overlaid around said store-and-forward switching circuitry.

25. The device of claim 20 wherein said layer one switching circuitry, said clock, said scheduler, and said controller are associated with a network element.

26. The device of claim 20 wherein said layer one switching circuitry, said clock, said scheduler, and said controller are associated with a LAN-attached device.

27. The device of claim 20 wherein said layer one switching circuitry, said clock, said scheduler, and said controller are associated with an end-user device.

28. The device of claim 20 further comprising buffers for holding information in conjunction with said layer one switching circuitry.

29. A method for switching information through a one or more of network elements, comprising the steps of:

associating a synchronization component with each of said one or more of network elements;

synchronizing said synchronization component in each of said one or more of network elements;

establishing a reservation schedule in each of said one or more of network elements, wherein said step of establishing a reservation schedule further comprises the steps of;

transmitting a request for a time-oriented reservation from a first network element to a second network element;

receiving said request for a time-oriented reservation in said second network element from said first network element; and

not scheduling requested time-oriented reservation in said second network element in accordance with said reservation schedule due to unavailable requested times.

30. A method for switching information through a one or more of network elements, comprising the steps of:

associating a synchronization component with each of said one or more of network elements;

synchronizing said synchronization component in each of said one or more of network elements;

establishing a reservation schedule in each of said one or more of network elements;

opening in each of said one or more of network elements a layer one connection at a time in accordance with said reservation schedule;

transmitting information from a source network element to a destination network element through said layer one connection in each of said one or more of network elements in accordance with said reservation schedule;

closing said layer one connection in each of said one or more of network elements;

transmitting a request from a first network element to terminate a time-oriented reservation;

receiving said request in a second network element to terminate said time-oriented reservation; and

de-scheduling said time-oriented reservation in said reservation schedule in said second network element in accordance with said request to terminate said time-oriented reservation, such that said time-oriented reservation times in said second network element become available for future time-oriented reservations.

31. A device for switching comprising:

layer one switching circuitry;

a clock;

a scheduler for scheduling layer one switching circuitry wherein said scheduler comprises a layer one event schedule wherein said layer one event schedule is a schedule comprising;

one or more layer one event times for each scheduled layer one event;

the identity of at least one input associated with said scheduled layer one event;

the identity of at least one output associated with said scheduled layer one event; and

an availability status for each scheduled layer one event, such that a layer one event may be scheduled at said one or more layer one event times, from said at least one input to said at least one output, with said availability status, and;

a controller for monitoring said clock and said scheduler, said controller adapted to activate said layer one switching circuitry in accordance with said scheduler and said clock.