Network assessment and fault isolation

• US 7,860,017 B2
• Filed: 10/27/2008
• Issued: 12/28/2010
• Est. Priority Date: 10/27/2008
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Montwill, Maciej
• Primary Examiner(s): Pham; Chi H
• Assistant Examiner(s): Ng; Fan
• Application Number:
  US12/258,646
• Publication Number:
  US 20100103822A1
• Time in Patent Office: 792 Days
• Field of Search: None
• US Class Current: 370/242
• CPC Class Codes: H04L 41/0645 by additionally acting on or stimulating the network after receiving notifications
• CPC Class Codes: H04L 41/0659 by isolating or reconfiguring faulty entities
• CPC Class Codes: H04L 41/0677 Localisation of faults
• CPC Class Codes: H04L 41/34 Signalling channels for network management communication
• CPC Class Codes: H04L 41/344 Out-of-band transfers
• CPC Class Codes: H04L 43/0829 Packet loss
• CPC Class Codes: H04L 43/087 Jitter
• CPC Class Codes: H04L 43/10 Active monitoring, e.g. heartbeat, ping or trace-route

Abstract

Fault isolation in a network includes embedding in-band traceroute packets in a media stream, passing the traceroute packets into a network connecting a proximal end point and a distal end point, monitoring the network for responses, expected from respective traceroute packets, from each of a plurality of network devices that are disposed between the proximal and distal end points; analyzing the respective responses; and based on the analyzing step, identifying one or more of the network devices as being responsible for a fault. In a preferred embodiment, fault isolation further includes correlating un-acknowledged, i.e., un-responded, traceroute packets with packet loss and or jitter computed at the distal end point.

Claims

1. A method comprising:

embedding in-band traceroute packets in traceroute frames that are interspersed with a media stream comprising a plurality of media frames;

transmitting the traceroute frames at a frequency of about once per 1.5 seconds into a network connecting a proximal end point and a distal end point;

monitoring the network for responses, expected from respective traceroute packets, from each of a plurality of network devices that are disposed between the proximal and distal end points;

analyzing the respective responses; and

based on the analyzing step, identifying one or more of the network devices as being responsible for a fault.

2. The method of claim 1, wherein the media steam comprises a high bandwidth video stream or a multiplexed video/audio stream over Internet Protocol (IP).

3. The method of claim 1, wherein the response comprises an Internet Control Message Protocol (ICMP) response.

4. The method of claim 1, further comprising matching a timing of any traceroute frame with a corresponding timing of packets of the media stream.

5. The method of claim 1, further comprising determining a network path and hop distance between the proximal and distal end points.

6. The method of claim 1, further comprising receiving computed end-to-end network loss and jitter from the distal end point, which measures statistics for an entire path being analyzed.

7. The method of claim 1, further comprising correlating un-acknowledged traceroute packets with packet loss at the distal end point.

8. The method of claim 1, further comprising correlating un-acknowledged traceroute packets with jitter between the proximal and distal end points.

9. The method of claim 1, further comprising transmitting the traceroute packets using realtime transport protocol (RTP).

10. The method of claim 1, further comprising assigning sequence values of the traceroute packets such that they are in sequence with sequence values of packets in the media stream.

11. The method of claim 1, further comprising transmitting a traceroute frame about every 45 media frames.

17. The method of claim 1, further comprising transmitting about 2400 traceroute frames per hour.

12. An apparatus comprising:

a transmitter configured to be connected to at least one network node that is part of a series of network nodes between the transmitter and a receiver, the transmitter configured to embed in-band traceroute packets in traceroute frames that are interspersed with a media stream comprising a plurality of media frames, transmit the traceroute frames at a frequency of about once per 1.5 seconds into a network connecting the transmitter and the receiver, monitor the network for responses, expected from respective traceroute packets, from each of the series of network nodes that are disposed between the transmitter and the receiver, analyze the respective responses, and based on analysis of the respective responses, identify one or more of the network nodes as being responsible for a fault.

13. The apparatus of claim 12, wherein the fault comprises packet loss.

14. The apparatus of claim 12, wherein the fault comprises jitter.

15. The apparatus of claim 12, wherein the transmitter is configured to receive computed end-to-end network loss and jitter from the receiver.

16. The apparatus of claim 12, wherein the transmitter is configured to assign sequence values of the traceroute packets such that they are in sequence with the sequence values of the packets in the media stream.