System and method for probing multiple paths in a network environment

• US 8,670,326 B1
• Filed: 03/31/2011
• Issued: 03/11/2014
• Est. Priority Date: 03/31/2011
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Balasubramanian, Hariharan, Rai, Smita, Sane, Sanjay
• Primary Examiner(s): Hsu, Alpus H
• Assistant Examiner(s): Patel, Dharmesh
• Application Number:
  US13/077,828
• Time in Patent Office: 1,076 Days
• Field of Search: 370/248, 370/351, 370/394, 370/238, 370/238.1, 370/252, 370/253, 370/392, 370/395.32, 709/238, 709/241, 709/227, 711/216
• US Class Current: 370/238
• CPC Class Codes: H04L 41/5009 Determining service level performance parameters or violations of service level contracts, e.g. violations of agreed response time or mean time between failures [MTBF]
• CPC Class Codes: H04L 43/0811 by checking connectivity
• CPC Class Codes: H04L 43/0852 Delays
• CPC Class Codes: H04L 43/10 Active monitoring, e.g. heartbeat, ping or trace-route
• CPC Class Codes: H04L 45/20 Hop count for routing purposes, e.g. TTL
• CPC Class Codes: H04L 45/22 Alternate routing
• CPC Class Codes: H04L 45/243 using M+N parallel active paths

Abstract

An example method is provided and can include initiating a probe session at a source network element; identifying multiple paths from the source network element to a destination network element in a network; transmitting packets from the source network element along the multiple paths; compiling a list of network characteristics associated with the multiple paths; and selecting a particular one of the multiple paths for packet routing based on the network characteristics.

Claims

1. A method, comprising:

initiating a probe session at a source network element;

identifying equal cost multiple paths from the source network element to a destination network element in a network by tracing routes over the equal cost multiple paths from the source network element to the destination element;

transmitting packets from the source network element along the equal cost multiple paths;

compiling a list of network characteristics associated with the equal cost multiple paths;

selecting a particular one of the equal cost multiple paths for packet routing based on the network characteristics; and

revising a previously performed hash with a different hash based on the network characteristics to re-inject particular packets toward the particular one of the equal cost multiple paths, wherein the different hash corresponds to the particular one of the equal cost multiple paths selected for packet routing.

2. The method of claim 1, wherein:

revising a previously performed hash with a different hash to re-inject particular packets towards the particular one of the equal cost multiple paths comprises designating using the different hash which next-hop network element particular packets are forwarded to if there are multiple next-hop network elements to reach the destination network element.

3. The method of claim 1, wherein identifying the multiple paths further comprises:

transmitting specific packets, which have an associated a time-to-live (TTL) value of 1, from the source network element to next-hop network elements;

collecting next-hop information at the source network element; and

increasing a subsequent TTL value by 1 with a successive transmitting activity until the destination network element is reached.

4. The method of claim 1, wherein the network characteristics are selected from a group of characteristics, the group of characteristics consisting of:

a) connectivity characteristics;

b) latency characteristics;

c) queuing delay characteristics; and

d) quality of service (QoS) characteristics.

5. The method of claim 1, wherein inner header values of selected packets are changed to different inner header values in order to route the selected packets along the particular one of the equal cost multiple paths, wherein the different inner header values comprises offset values corresponding to the particular one of the equal cost multiple paths.

6. The method of claim 1, further comprising:

changing a port characteristic of selected packets based on the network characteristics such that the selected packets are routed toward the particular one of the multiple paths.

7. The method of claim 1, wherein the network includes a Data Center Ethernet (DCE) network.

8. Logic encoded in non-transitory computer-readable media that includes code for execution and when executed by a processor operable to perform operations comprising:

initiating a probe session at a source network element;

identifying equal cost multiple paths from the source network element to a destination network element in a network by tracing routes over the equal cost multiple paths from the source network element to the destination element;

transmitting packets from the source network element along the equal cost multiple paths;

compiling a list of network characteristics associated with the equal cost multiple paths;

selecting a particular one of the equal cost multiple paths for packet routing based on the network characteristics; and

revising a previously performed hash with a different hash based on the network characteristics to re-inject particular packets toward the particular one of the equal cost multiple paths, wherein the different hash corresponds to the particular one of the equal cost multiple paths selected for packet routing.

9. The logic of claim 8, wherein:

revising a previously performed hash with a different hash to re-inject particular packets towards the particular one of the equal cost multiple paths comprises designating using the different hash which next-hop network element particular packets are forwarded to if there are multiple next-hop network elements to reach the destination network element.

10. The logic of claim 8, wherein identifying the multiple paths further comprises:

transmitting specific packets, which have an associated a time-to-live (TTL) value of 1, from the source network element to next-hop network elements;

collecting next-hop information at the source network element; and

increasing a subsequent TTL value by 1 with a successive transmitting activity until the destination network element is reached.

11. The logic of claim 8, wherein inner header values of selected packets are changed to different inner header values in order to route the selected packets along the particular one of the equal costs multiple paths, wherein the different inner header values comprises offset values corresponding to the particular one of the equal cost multiple paths.

12. The logic of claim 8, the operations further comprising:

changing a port characteristic of selected packets based on the network characteristics such that the selected packets are routed toward the particular one of the multiple paths.

13. The logic of claim 8, wherein the network includes a Data Center Ethernet (DCE) network.

14. An apparatus, comprising:

a memory element configured to store electronic code;

a processor operable to execute instructions associated with the electronic code; and

a multipath module configured to interface with the processor such that the apparatus is configured for;

initiating a probe session at a source network element;

identifying equal cost multiple paths from the source network element to a destination network element in a network by tracing routes over the equal cost multiple paths from the source network element to the destination element;

transmitting packets from the source network element along the equal cost multiple paths;

compiling a list of network characteristics associated with the equal cost multiple paths;

selecting a particular one of the equal cost multiple paths for packet routing based on the network characteristics; and

revising a previously performed hash with a different hash based on the network characteristics to re-inject particular packets toward the particular one of the equal cost multiple paths, wherein the different hash corresponds to the particular one of the equal cost multiple paths selected for packet routing.

15. The apparatus of claim 14, wherein:

revising a previously performed hash with a different hash to re-inject particular packets towards the particular one of the equal cost multiple paths comprises designating using the different hash which next-hop network element particular packets are forwarded to if there are multiple next-hop network elements to reach the destination network element.

16. The apparatus of claim 14, wherein identifying the multiple paths further comprises:

transmitting specific packets, which have an associated a time-to-live (TTL) value of 1, from the source network element to next-hop network elements;

collecting next-hop information at the source network element; and

increasing a subsequent TTL value by 1 with a successive transmitting activity until the destination network element is reached.

17. The apparatus of claim 14, wherein the network characteristics are selected from a group of characteristics, the group of characteristics consisting of:

e) connectivity characteristics;

f) latency characteristics;

g) queuing delay characteristics; and

h) quality of service (QoS) characteristics.

18. The apparatus of claim 14, wherein inner header values of selected packets are changed to different inner header values in order to route the selected packets along the particular one of the equal costs multiple paths, wherein the different inner header values comprises offset values corresponding to the particular one of the equal cost multiple paths.

19. The apparatus of claim 14, the apparatus being further configured for:

changing a port characteristic of selected packets based on the network characteristics such that the selected packets are routed toward the particular one of the multiple paths.

20. The apparatus of claim 14, wherein the network includes a Data Center Ethernet (DCE) network.