System and method for tracking packets in a network environment

Patent metadata

Field	Value
Publication number	US-9450846-B1
Application number	US-201213653814-A
Country	US
Kind code	B1
Filing date	Oct 17, 2012
Priority date	Oct 17, 2012
Publication date	Sep 20, 2016
Grant date	Sep 20, 2016

Abstract

A method is provided in one example embodiment that includes transmitting a message from a first port to a second port, recording a timestamp of the message at each clock between the first port and the second port, and transmitting a first follow-up message from a first port to a second port to collect timestamps at each clock between the first port and the second port. The method further includes transmitting a loopback message from the second port to the first port, recording timestamps of the loopback message at each clock between the second port and the first port, and transmitting a second follow-up message from the second port to the first port to collect and append the timestamps of the loopback message at each clock.

First claim

What is claimed is:

1. A method for tracking packets in a network to monitor health of the network, comprising:
transmitting a message from a first port of a first network element via a second network element to a second port of a third network element;
recording a first timestamp of the message at the first network element relative to a first clock associated with the first network element;
recording a second timestamp of the message at the second network element relative to a second clock associated with the second network element;
recording a third timestamp of the message at the third network element relative to a third clock associated with the third network element, wherein the message is terminated and regenerated at the second clock and the third clock;
transmitting a first follow-up message from the first port to the second port to collect and append the first timestamp, the second timestamp, and the third timestamp to the first follow-up message, wherein the appended first follow-up message includes: a header portion having an insertion code field indicative of either a hop-by-hop timestamp insertion mode or an endpoint timestamp insertion mode, and a record count field indicative of a number of timestamps included within the first follow-up message; a first timestamp record including a first port identifier associated with the first timestamp, a first format field indicative of a format associated with the first port identifier, and the first timestamp; a second timestamp record including a second port identifier associated with the second timestamp, a second format field indicative of a format associated with the second port identifier, and the second timestamp; and a third timestamp record including a third port identifier associated with the third timestamp, a third format field indicative of a format associated with the third port identifier, and the third timestamp, wherein the first follow-up message is a negotiated message;
transmitting a loopback message from the second port to the first port;
recording timestamps of the loopback message at each clock between the second port and the first port; and
transmitting a second follow-up message from the second port to the first port to collect and append the timestamps of the loopback message at each clock.

2. The method of claim 1 , wherein the message being transmitted is a probe message.

3. The method of claim 1 , wherein the message being transmitted is a probe message injected at an interface of a network element.

4. The method of claim 3 , wherein the interface of the network element includes one or more of an ingress port of a switch, an ingress port of a router, and an egress port of a network interface card.

5. The method of claim 1 , wherein the message being transmitted is a probe message terminated and regenerated at the first clock and the second clock.

6. The method of claim 1 , wherein the first and second follow-up messages are precision time protocol messages.

7. The method of claim 1 , wherein the first and second follow-up messages are precision time protocol messages each comprising a sequence identifier, a time stamp header, and time stamp records.

8. The method of claim 1 , wherein:
the message is a probe message terminated and regenerated at the first clock and the second clock; and
the first and second follow-up messages are precision time protocol messages each comprising a sequence identifier, a time stamp header, and time stamp records.

9. The method of claim 1 , wherein the recording of the timestamps of the message is performed in-line with the transmitting of the message.

10. Logic encoded in one or more non-transitory, tangible media that includes code for execution and when executed by a processor operable to perform operations for tracking packets in a network to monitor health of the network comprising:
transmitting a message from a first port of a first network element via a second network element to a second port of a third network element;
recording a first timestamp of the message at the first network element relative to a first clock associated with the first network element;
recording a second timestamp of the message at the second network element relative to a second clock associated with the second network element;
recording a third timestamp of the message at the third network element relative to a third clock associated with the third network element, wherein the message is terminated and regenerated at the second clock and the third clock;
transmitting a first follow-up message from the first port to the second port to collect and append the first timestamp, the second timestamp, and the third timestamp to the first follow-up message, wherein the appended first follow-up message includes: a header portion having an insertion code field indicative of either a hop-by-hop timestamp insertion mode or an endpoint timestamp insertion mode, and a record count field indicative of a number of timestamps included within the first follow-up message; a first timestamp record including a first port identifier associated with the first timestamp, a first format field indicative of a format associated with the first port identifier, and the first timestamp; a second timestamp record including a second port identifier associated with the second timestamp, a second format field indicative of a format associated with the second port identifier, and the second timestamp; and a third timestamp record including a third port identifier associated with the third timestamp, a third format field indicative of a format associated with the third port identifier, and the third timestamp, wherein the first follow-up message is a negotiated message;
transmitting a loopback message from the second port to the first port;
recording timestamps of the loopback message at each clock between the second port and the first port; and
transmitting a second follow-up message from the second port to the first port to collect and append the timestamps of the loopback message at each clock.

11. The logic of claim 10 , wherein the message being transmitted is a probe message.

12. The logic of claim 10 , wherein the message being transmitted is a probe message terminated and regenerated at the second clock and the third clock.

13. The logic of claim 10 , wherein the first and second follow-up messages are precision time protocol messages.

14. The logic of claim 10 , wherein the first and second follow-up messages are precision time protocol messages each comprising a sequence identifier, a time stamp header, and time stamp records.

15. The logic of claim 10 , wherein:
the message is a probe message terminated and regenerated at the second clock and the third clock; and
the first and second follow-up messages are precision time protocol messages each comprising a sequence identifier, a time stamp header, and time stamp records.

16. The logic of claim 10 , wherein the recording of the timestamps of the message is performed in-line with the transmitting of the message.

17. An apparatus for tracking packets in a network to monitor health of the network, comprising:
a memory element configured to store data,
a processor operable to execute instructions associated with the data, and
a tracking module, the apparatus being configured to:
transmit a message from a first port of a first network element via a second network element to a second port of a third network element;
record a first timestamp of the message at the first network element relative to a first clock associated with the first network ele

Assignees

• Cisco Tech Inc

Inventors

• Huang Wei-Jen
• Huang Chih-Tsung

Classifications

• H04L43/0858 Primary

  One way delays · CPC title

• H04L43/12

  Network monitoring probes · CPC title

• H04J3/0682

  by delay compensation, e.g. by compensation of propagation delay or variations thereof, by ranging · CPC title

• H04L43/106

  using time related information in packets, e.g. by adding timestamps · CPC title

• H04L43/0864

  Round trip delays · CPC title