Packet network timing analyzer

• US 4,916,694 A
• Filed: 12/22/1988
• Issued: 04/10/1990
• Est. Priority Date: 12/22/1988
• Status: Expired due to Term

• Current Assignee: Micron Technology, Inc.
• Original Assignee: AMP Incorporated (Johnson Controls International plc)
• Inventors: Roth, Jacques A.
• Primary Examiner(s): Olms, Douglas W.
• Assistant Examiner(s): Hsu, Alpus H.
• Application Number:
  US07/289,090
• Time in Patent Office: 474 Days
• Field of Search: 370/85, 370/94, 370/60, 370/13, 370/86, 370/89, 375/10, 375/112, 379/10, 379/34, 379/88, 379/89, 340/720, 382/1
• US Class Current: 370/252
• CPC Class Codes: H04L 43/00 Arrangements for monitoring or testing data switching networks

Abstract

A local area network timing analyzer responds to a signal on a local area network to generate a carrier detect signal which is indicative of the presence or absence of signaling activity on the local area network. The carrier detect signal alternates between two logic states indicative of packets and gaps between packets. The timing analyzer stores an array of timing entries, and individual ones of these timing entries are indicative of the time duration of individual gaps and packets. These timing entries are sorted and otherwise used to display timing information for the local area network.

Claims

1. A packet network timing analyzer comprising:

means, responsive to a signal on a packet network, for generating a carrier detect signal in a first state during packet intervals characterized by signalling activity on the packet network and in a second state during gaps characterized by an absence of signalling activity on the packet network;

and means for storing a plurality of timing entries indicative of the development in time of the carrier detect signal, said timing entries stored at periodic intervals determined by changes in state of the carrier detect signal.

2. The invention of claim 1 wherein said storing means stores timing entries both for time periods when the carrier detect signal is in the first state and for time periods when the carrier detect signal is in the second state.

3. The invention of claim 1 wherein alternate ones of the timing entries relate to time periods when the carrier detect signal is in the first state and intervening ones of the timing entries relate to time periods when the carrier detect signal is in the second state.

4. The invention of claim 1 wherein the packet network is a local area network which comprises a fiber optic signal transmission medium, and wherein the local area network carries optical signals on the fiber optic signal transmission medium.

5. A packet network timing analyzer comprising:

means, responsive to a signal on a packet network, for generating a carrier detect signal in a first state during packet intervals characterized by signalling activity on the packet network and in a second state during gaps characterized by an absence of signalling activity on the packet network; and

means for timing a plurality of elapsed times, each indicative of a duration of a respective time period when the carrier detect signal is in one of the first and second states, and for generating a plurality of timing entries indicative of said elapsed times; and

means for storing said timing entries for later analysis.

6. The invention of claim 5 wherein said timing means generates timing entries both for time periods when the carrier detect signal is in the first state and for time periods when the carrier detect signal is in the second state.

7. The invention of claim 5 wherein alternate ones of the timing entries relate to time periods when the carrier detect signal is in the first state and intervening ones of the timing entries relate to time periods when the carrier detect signal is in the second state.

8. The invention of claim 5 wherein the packet network is a local area network which comprises a fiber optic signal transmission medium, and wherein the local area network carries optical signals on the fiber optic signal transmission medium.

9. A packet network timing analyzer comprising:

means, responsive to a signal on a packet network, for generating a carrier detect signal in a first state during packet intervals characterized by signalling activity on the packet network and in a second state during gaps characterized by an absence of signalling activity on the packet network;

means for storing a plurality of timing entries indicative of the development in time of the carrier detect signal, said storing means storing only one timing entry for each change of state of the carrier detect signal.

10. The invention of claim 9 wherein said storing means stores timing entries both for time periods when the carrier detect signal is in the first state and for time periods when the carrier detect signal is in the second state.

11. The invention of claim 9 wherein alternate ones of the timing entries relate to time periods when the carrier detect signal is in the first state and intervening ones of the timing entries relate to time periods when the carrier detect signal is in the second state.

12. The invention of claim 9 wherein the packet network is a local area network which comprises a fiber optic signal transmission medium, and wherein the local area network carries optical signals on the fiber optic signal transmission medium.

13. A packet network timing analyzer comprising:

means, responsive to a signal on a packet network, for generating a carrier detect signal in a first state during packet intervals characterized by signalling activity on the packet network and in a second state during gaps characterized by an absence of signalling activity on the packet network;

means for storing a plurality of timing entries indicative of the development in time of the carrier detect signal; and

means for sorting the stored timing entries to locate the stored timing entries that meet selected sorting criteria.

14. The invention of claim 13 wherein the selected sorting criteria comprise the criterion that stored timing entries indicate packet intervals shorter than a selected duration.

15. The invention of claim 14 wherein the selected duration is characeristic of incomplete signal packets on the local area network.

16. The invention of claim 13 wherein the selected sorting criteria comprise the criterion that stored timing entries indicate gaps shorter than a selected duration.

17. The invention of claim 13 wherein said storing means stores timing entries both for time periods when the carrier detect signal is in the first state and for time periods when the carrier detect signal is in the second state.

18. The invention of claim 13 wherein alternate ones of the timing entries relate to time periods when the carrier detect signal is in the first state and intervening ones of the timing entries relate to time periods when the carrier detect signal is in the second state.

19. The invention of claim 13 wherein the packet network is a local area network which comprises a fiber optic signal transmission medium, and wherein the local area network carries optical signals on the fiber optic signal transmission medium.

20. A packet network timing analyzer comprising:

means, responsive to a signal on a local area network, for generating a carrier detect signal indicative of the presence on signalling activity on the packet network;

means, responsive to the carrier detect signal, for storing information indicative of a pattern of generation of the carrier detect signal, said information storing means comprising means for storing a sequence of timing entries, a first set of said timing entries each being indicative of a duration of a respective time interval during which the carrier detect signal is generated; and

means for utilizing the timing entries to display timing information for the packet network.

21. The invention of claim 20 wherein a second set of timing entries is each indicative of a duration of a respective time interval during which the carrier detect signal is not generated.

22. The invention of claim 20 wherein the packet network is a local area network which comprises a fiber optic signal transmission medium, and wherein the local area network carries optical signals on the fiber optic signal transmission medium.