Buffer Circuitry for Monitoring Network Element Status

• US 20160248689A1
• Filed: 03/17/2015
• Published: 08/25/2016
• Est. Priority Date: 02/20/2015
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Akhbarizadeh, Mohammad Jafar, Griswold, Mark David
• Granted Patent: US 10,505,854 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H04L 43/0817 by checking functioning
• CPC Class Codes: H04L 47/30 in combination with information about buffer occupancy at either end or at transit nodes
• CPC Class Codes: H04L 47/32 by discarding or delaying data units, e.g. packets or frames

Abstract

A system includes a pre-trigger buffer and a post-trigger buffer for recording entries related to specific network element. Buffer management monitoring circuitry captures entries leading up to a trigger criterion being met in the pre-trigger buffer and entries following the trigger criterion being met in the post-trigger buffer. The trigger criterion may include network element status, such as a threshold queue level; or an event, such as a dropped packet. The pre-trigger buffer may include a circular buffer in which older entries are overwritten by newer entries. Once the trigger condition is met, the pre-trigger buffer contents are held while the post-trigger buffer fills. Once the post-trigger buffer fills, the contents of the buffers may be read.

Claims

1. A method comprising:

when a first criterion is met by a first network element in a network comprising multiple network elements, recording events corresponding to the first network element in a first buffer;

when a second criterion is met by a triggering network element of the multiple network elements, recording events corresponding to the triggering network element in a second buffer; and

when the second buffer meets a freeze criterion;

holding content of the second buffer static; and

causing a host processor to access the content of the first and second buffers.

2. The method of claim 1, where the first network element and the triggering network element comprise the same network element.

3. The method of claim 1, where the first criterion and the second criterion comprise threshold values.

4. The method of claim 3, where the threshold values comprise an egress buffer level threshold, an ingress buffer level threshold, or any combination thereof.

5. The method of claim 1, further comprising overwriting a recorded event in the first buffer when the first buffer fills.

6. The method of claim 5, where the recorded event comprises an oldest recorded event in the first buffer.

7. The method of claim 1, where the recording an event in the second buffer comprises overwriting an entry in the first buffer.

8. The method of claim 1, where the triggering network element meets the second criterion by dropping a packet responsive to congestion, buffer admission, or both.

9. The method of claim 1, further comprising recording events corresponding to a second network element in the first buffer responsive to the first criterion being met by the first network element, the second network element different from the first network element.

10. The method of claim 1, further comprising randomly sampling events;

and where recording events recording a randomly sampled event.

11. The method of claim 1, further comprising:

defining a qualified group from among the multiple network elements;

adding the first network element to the qualified group when the first criterion is met by the first network element; and

after adding the first network element to the qualified group, removing the first network element from the qualified group responsive to the first element failing to meet the first criterion.

12. A device comprising:

buffer circuitry configured to record event entries;

a communication interface in data communication with the buffer circuitry, the communication interface configured to allow a host processor to access the event entries in the buffer circuitry; and

monitoring circuitry configured to;

monitor multiple network elements;

when a first criterion is met by a first network element of the multiple network elements, cause the buffer circuitry to record event entries for the first network element;

when a second criterion is met by a second condition of a triggering network element of the multiple network elements, the second criterion different from the first criterion, cause the buffer circuitry to record event entries for the triggering network element; and

when a freeze condition is met, cause the buffer circuity to stop recording event entries.

13. The device of claim 12, where the buffer circuitry is configured to record a first event over a second event when the buffer circuitry is full.

14. The device of claim 13, where:

the first event comprises a newest event; and

the second event comprises an oldest event.

15. The device of claim 13, where:

the first event comprises an event occurring before second criterion is met; and

the second event comprises an event occurring after second criterion is met.

16. The device of claim 12, where the monitoring circuitry is configured to:

randomly sample events corresponding to the first network element; and

cause the buffer circuitry to record event entries for the first network element by recording a randomly sampled event.

17. The device of claim 12, where:

the buffer circuitry comprises;

a first buffer; and

a second buffer;

the first buffer is configured to store event entries occurring after the first criterion is met but before the second criterion is met; and

the second buffer is configured to store event entries occurring after the second criterion is met.

18. The device of claim 12, where the buffer circuitry is configured to record an event by recording, a status condition, a time stamp, a network element identifier, or any combination thereof.

19. A device comprising:

first buffer circuitry;

second buffer circuitry; and

monitoring circuitry configured to;

monitor multiple network elements;

responsive to a first network element of the multiple network elements meeting a first criterion but before a second network element meets a second criterion, record a first entry attributed to the first network element in the first buffer circuitry;

responsive to a second network element meeting the second criterion;

record a second entry attributed to the second network element in the first buffer circuitry; and

record a third entry attributed to the second network element in the second buffer circuitry; and

responsive to a third network element meeting the second criterion;

record a fourth entry attributed to the third network element in the second buffer circuitry; and

forgo recording a fifth entry attributed to the third network element in the first buffer circuitry.

20. The device of claim 19, where the first network element and the second network element comprise the same network element.