System and method for tracking packets in a network environment

• US 9,450,846 B1
• Filed: 10/17/2012
• Issued: 09/20/2016
• Est. Priority Date: 10/17/2012
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Huang, Wei-Jen, Huang, Chih-Tsung
• Primary Examiner(s): Cho, Un C
• Assistant Examiner(s): Rahman, Shah
• Application Number:
  US13/653,814
• Time in Patent Office: 1,434 Days
• Field of Search: 370/241, 370/242
• US Class Current: 1/1
• CPC Class Codes: H04J 3/0667 Bidirectional timestamps, e.g. NTP or PTP for compensation of clock drift and for compensation of propagation delays arrangements for monitoring round trip delays in packet switching networks H04L43/0864
• CPC Class Codes: H04J 3/0682 by delay compensation, e.g. by compensation of propagation delay or variations thereof, by ranging
• CPC Class Codes: H04J 3/0697 Synchronisation in a packet node
• CPC Class Codes: H04L 43/0858 One way delays
• CPC Class Codes: H04L 43/0864 Round trip delays
• CPC Class Codes: H04L 43/10 Active monitoring, e.g. heartbeat, ping or trace-route
• CPC Class Codes: H04L 43/106 using time related information in packets, e.g. by adding timestamps
• CPC Class Codes: H04L 43/12 Network monitoring probes

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.

Claims

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 element;

record a second timestamp of the message at the second network element relative to a second clock associated with the second network element;

record 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;

transmit 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;

transmit a loopback message from the second port to the first port;

record timestamps of the loopback message at each clock between the second port and the first port; and

transmit 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.

18. The apparatus of claim 17, wherein the message being transmitted is a probe message.

19. The apparatus of claim 17, wherein the message being transmitted is a probe message terminated and regenerated at the second clock and the third clock.

20. The apparatus of claim 17, wherein the first and second follow-up messages are precision time protocol messages.

21. The apparatus of claim 17, 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.

22. The apparatus of claim 17, 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.

23. The apparatus of claim 17, wherein the recording of the timestamps of the message is performed in-line with the transmitting of the message.