Network Assessment and Fault Isolation

• US 20100103822A1
• Filed: 10/27/2008
• Published: 04/29/2010
• 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
• Granted Patent: US 7,860,017 B2
• Time in Patent Office: Days
• 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 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.

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 embedding the traceroute packets in a traceroute frame.

5. The method of claim 4, further comprising transmitting the traceroute frame no more than once per second.

6. The method of claim 5, further comprising transmitting the traceroute frame at a frequency of about once per 1.5 seconds.

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

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

9. 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.

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

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

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

13. 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.

14. 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 a media stream, pass the traceroute packets 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.

15. The apparatus of claim 14, wherein the fault comprises packet loss.

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

17. The apparatus of claim 14, wherein the transmitter is configured to receive computed end-to-end network loss and jitter from the receiver.

18. The apparatus of claim 14, 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

19. Logic encoded in one or more tangible media for execution and when executed operable to:

embed in-band traceroute packets in a media stream;

pass the traceroute packets into a network connecting a proximal end point and a distal end point;

monitor 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;

analyze the respective responses; and

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

20. The logic of claim 19, further operable to match a timing of the traceroute frame comprising the traceroute packets with a timing of frames of the media stream.