Method and apparatus for transfer information using optical fiber connections

• US 6,473,782 B1
• Filed: 08/20/1999
• Issued: 10/29/2002
• Est. Priority Date: 10/14/1998
• Status: Expired due to Term

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Huang, Catherine C., Flanagan, John R., Ricci, Louis W., Casper, Daniel F., Frazier, Giles R., Dugan, Robert J., Elliott, Joseph C.
• Primary Examiner(s): Harrell, Robert B.
• Application Number:
  US09/379,150
• Time in Patent Office: 1,166 Days
• Field of Search: 709/200, 709/201, 709/212, 709/213, 709/223
• US Class Current: 709/201
• CPC Class Codes: G06F 11/1004 to protect a block of data words, e.g. CRC or checksum G06F11/1076 takes precedence; security arrangements for protecting computers or computer systems against unauthorized activity G06F21/00
• CPC Class Codes: G06F 11/1443 Transmit or communication errors

Abstract

The present invention provides for a method of transferring information in a network computing system environment. The network environment includes a main storage coupled to a channel subsystem with a plurality of channels which is in processing communication with a control unit capable of coupling to a plurality of input/output devices. At first the packets of data are sent concurrently to and from the main storage. Next execution of certain channel functions are transferred to the control unit so that certain commands can be combined with the data packets in one sequence. Finally only one start data command and only one end command notification needs to be sent before and after a plurality of data packets is transferred respectively. In one embodiment another method is employed in the same network computing system environment having the steps of: fetching said command from said main storage; fetching associated data from said main storage; and transferring said fetched command along with said fetched associated data to said control unit.

Claims

1. In a network computing system environment wherein information comprising data and commands are transferred between a main storage and at least one control unit over a plurality of channels;

a method for transferring said information;

comprising the steps of;

fetching said command from said main storage;

fetching associated data from said main storage; and

,

transferring said fetched command along with said fetched associated data to said control unit;

said fetched command and associated data including a plurality of channel control words (CCWs) pipelined together to send associated processed data and commands to the control unit without interlocking responses from said control unit such that multiple channel programs to the control unit are time division multiplexed.

2. The method of claim 1, wherein said CCWs are chained further without intermediate Status Sequences.

3. The method of claim 2, wherein said control unit(s) and channels are in processing communication with an optical fiber.

4. The method of claim 3, wherein said transferring of information involves time division multiplexing of multiple exchanges over the same link.

5. The method of claim 4, wherein said transferring of information involves time division multiplexing of multiple exchanges over the same fiber optic link.

6. The method of claim 5, wherein said multiplexing involves multiple channel programs to be exchanged at the same time with different devices.

7. The method of claim 1, wherein said channel subsystem is in processing communication with a storage control element coupled to said main storage.

8. The method of claim 7, wherein said storage control element is also in processing communication with at least one central processing unit.

18. The method of claim 1, wherein said control units and said channels are in processing communication with an optical fabric.

19. The method of claim 18, wherein said transferring of information involves time division multiplexing of multiple exchanges over the same fiber optic link.

21. The method of claim 18, wherein said fabric comprises optical fiber.

22. The method of claim 18, wherein said fabric comprises a plurality of fiber optic switches.

23. The method of claim 1, wherein each Write CCW is sent as one sequence.

24. The method of claim 23, wherein if a Write CCW is longer than a certain length, any portion of said Write CCW that exceeds said length is sent as a separate data sequence.

25. The method of claim 24, wherein said certain length is equal to 4K.

28. The method of claim 1, wherein said channel subsystem is in processing communication with a storage control element coupled to said main storage.

29. The method of claim 28, wherein said storage control element is also in processing communication with at least one central processing unit.

30. The method of claim 1, wherein said CCWs are chained together without intermediate Status Sequences.

32. The method of claim 1, wherein said transferring of information involves time division multiplexing of multiple exchanges over the same link.

33. The method of claim 1, wherein each Read CCW is sent as one sequence.

9. In a network computing system environment wherein information comprising data and commands are transferred between a main storage and at least one control unit over a plurality of channels, an apparatus for transferring said information comprising:

a first requester fetching said command and associated data from said main storage; and

,

a first transmitter transferring said fetched command along with said fetched associated data to said control unit;

said fetched command and associated data transmitted by said first transmitter including a plurality of channel control words (CCWs) pipelined together to send associated processed data and commands to the control unit without interlocking responses from said control unit such that multiple channel programs to the control unit are time division multiplexed.

10. The apparatus of claim 9, wherein said CCWs are chained without intermediate Status Sequences.

11. The apparatus of claim 10, wherein said control unit(s) and channels are in processing communication with an optical fiber.

12. The apparatus of claim 11, wherein said transferring of information involves time division multiplexing of multiple exchanges over the same link.

13. The apparatus of claim 12, wherein said transferring of information involves time division multiplexing of multiple exchanges over the same fiber optic link.

14. The apparatus of claim 13, wherein said multiplexing involves multiple channel programs to be exchanged at the same time with different devices.

15. The apparatus of claim 9, wherein said channel subsystem is in processing communication with a storage control element coupled to said main storage.

16. The apparatus of claim 15, wherein said storage control element is also in processing communication with at least one central processing unit.

20. The method of claim 10, wherein said multiplexing involves multiple channel programs to be exchanged at the same time with different devices.

17. A method for transferring information in a network computing system environment having a main storage coupled to a channel subsystem with a plurality of channels and in processing communication with a plurality of control units capable of connecting with a plurality of input/output devices, comprising the steps of:

concurrently sending packets of data consecutively to and from said main storage;

transferring execution of channel functions to said control units so that commands can be combined with said data packets in one sequence; and

,

sending only one start data command before a plurality of data packets is transferred and only one end command notification after said start data command and said plurality of data packets is transferred;

said plurality of data packets including a plurality of channel control words (CCWs) pipelined together to send associated processed data and commands to said control units without interlocking responses from said control units such that multiple channel programs to the same or different control units are time division multiplexed between said one start data command and said one end command notification.

26. The method of claim 17, wherein said control units and said channels are in processing communication with at least one fiber optic switch.

27. The method of claim 26, wherein at least one optical fiber is also used in establishing processing communication between said control units and said channels.

31. The method of claim 17, wherein at least one control unit is dedicated to each input/output device.

34. An apparatus for transferring information in a network computing system environment having a main storage coupled to a channel subsystem with a plurality of channels and in processing communication with a plurality of control units capable of connecting with a plurality of input/output devices, said apparatus comprising:

a first transmitter/receiver in said channel subsystem concurrently sending packets of data consecutively to and from said main storage;

a dispatcher in said channel subsystem transferring execution of channel functions to said control units so that commands can be combined with said data packets in one sequence; and

,

a second transmitter/receiver in said channel subsystem sending only one start data command and only one end command notification respectively, before and after a plurality of data packets is transferred;

said plurality of data packets sent by said second transmitter/receiver including a plurality of channel control words (CCWs) pipelined together to send associated processed data and commands to said control units without interlocking responses from said control units such that multiple channel programs to the same or different control units are time division multiplexed between said one start data command and said one end command notification.

35. The apparatus of claim 34, wherein said control units and said channels are in processing communication with an optical fabric.

36. The apparatus of claim 35, wherein said transferring of information involves time division multiplexing of multiple exchanges over the same fiber optic link.

37. The apparatus of claim 36, wherein said multiplexing involves multiple channel programs to be exchanged at the same time with different devices.

38. The apparatus of claim 35, wherein said fabric comprises a plurality of fiber optic switches.

39. The apparatus of claim 38, wherein said storage control element is also in processing communication with at least one central processing unit.

40. The apparatus of claim 35, wherein said fabric comprises optical fiber.

41. The apparatus of claim 34, wherein each Write CCW is sent as one sequence.

42. The apparatus of claim 41, wherein if a Write CCW is longer than a certain length, any portion of said Write CCW that exceeds said length is sent as a separate data sequence.

43. The apparatus of claim 42, wherein said length is equal to 4K.

44. The apparatus of claim 34, wherein said control units and said channels are in processing communication with at least one fiber optic switch.

45. The apparatus of claim 35, wherein at least one optical fiber is also used in establishing processing communication between said control units and said channels.

46. The apparatus of claim 34, wherein said CCWs are chained together with no intermediate Status Sequences.

47. The apparatus of claim 34, wherein at least one control unit is dedicated to each input/output device.

48. The apparatus of claim 34, wherein said transferring of information involves time division multiplexing of multiple exchanges over the same link.

49. The apparatus of claim 34, wherein each Read CCW is sent as one sequence.

50. The apparatus of claim 34, wherein said channel subsystem is in processing communication with a storage control element coupled to said main storage.