SWITCHING AND LOAD BALANCING TECHNIQUES IN A COMMUNICATION NETWORK

• US 20200136999A1
• Filed: 10/26/2018
• Published: 04/30/2020
• Est. Priority Date: 10/26/2018
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: LEVY-ABEGNOLI, Eric M., THUBERT, Pascal, WETTERWALD, Patrick
• Granted Patent: US 10,771,405 B2
• Time in Patent Office: Days
• CPC Class Codes: H04L 45/64 using an overlay routing layer
• CPC Class Codes: H04L 45/7453 using hashing
• CPC Class Codes: H04L 47/11 Identifying congestion
• CPC Class Codes: H04L 47/125 by balancing the load, e.g. traffic engineering
• CPC Class Codes: H04L 47/32 by discarding or delaying data units, e.g. packets or frames
• CPC Class Codes: H04L 49/1515 Non-blocking multistage, e.g. Clos
• CPC Class Codes: H04L 49/1569 Clos switching fabrics
• CPC Class Codes: H04L 49/25 Routing or path finding in a switch fabric
• CPC Class Codes: H04L 49/501 Overload detection
• CPC Class Codes: H04L 49/9089 replacing packets in a storage arrangement, e.g. pushout

Abstract

A source access network device multicasts copies of a packet to multiple core switches, for switching to a same target access network device. The core switches are selected for the multicast based on a load balancing algorithm managed by a central controller. The target access network device receives at least one of the copies of the packet and generates at least metric indicative of a level of traffic congestion at the core switches and feeds back information regarding the recorded at least one metric to the controller. The controller adjusts the load balancing algorithm based on the fed back information for selection of core switches for a subsequent data flow.

Claims

1. A method for switching data in a communication network, comprising:

obtaining at a source access network device a packet to send to a target access network device, wherein each of the source access network device and the target access network device is coupled to each of a plurality of core network devices;

transmitting by the source access network device the packet to a first core network device for switching to the target access network device, wherein the first core network device is selected from the plurality of core network devices based on a load balancing algorithm configured by a controller;

transmitting by the source access network device at least one copy of the packet to a respective second core network device for switching to the target access network device;

receiving at the target access network device at least one of the packet or the at least one copy of the packet;

generating by the target access network device based on the receiving, at least one metric indicative of a level of traffic congestion at the first and second core network devices;

transmitting by the target access network device information regarding the at least one metric to the controller; and

adjusting the load balancing algorithm based on the at least one metric.

2. The method of claim 1, further comprising transmitting by the source access network device at least one subsequent packet based on the adjusted load balancing algorithm.

3. The method of claim 1, further comprising receiving at the source access network device the packet from a source end point device for transmitting to a target end point device coupled to the target access network device.

4. The method of claim 3, wherein, after the recording, the target access network device forwards one of the packet or the at least one copy of the packet to the target end point device and discards the other packet.

5. The method of claim 1, further comprising:

detecting that the packet is part of a critical traffic flow; and

wherein the transmitting by the source access network device the packet and the at least one copy of the packet is in response to detecting that the packet is part of the critical traffic flow.

6. The method of claim 5, further comprising receiving by the source access network device from the controller an indication of the critical traffic flow.

7. The method of claim 1, wherein the packet is part of operations, administration and maintenance (OAM) traffic.

8. The method of claim 7, wherein, after the recording, the target access network device discards the packet and the at least one copy of the packet.

9. The method of claim 1, further comprising receiving at the source network device a first indication from the controller to transmit the packet to the first core network device, wherein the first indication is based on the load balancing algorithm.

10. The method of claim 9, further comprising receiving at the source network device a second indication from the controller to transmit the at least one copy of the packet to the respective second core network device, wherein the second indication is based on the load balancing algorithm.

11. The method of claim 1, wherein the respective second core network device is selected based on a random algorithm.

12. The method of claim 1, further comprising:

replicating by the source access network device the packet using a redundancy protocol to generate the at least one copy of the packet.

13. The method of claim 1, further comprising:

tagging by the source access network device the packet with a highest priority; and

tagging by the source access network device the at least one copy of the packet with a lower priority.

14. The method of claim 13, wherein each of the plurality of core network devices is configured to switch packets from highest to lowest priorities.

15. A communication network for switching data, comprising:

a controller for managing switching of traffic flows in the communication network;

a plurality of core network devices;

a source access network device; and

a target access network device, wherein each of the source access network device and the target access network device is coupled to each of a plurality of core network devices,

wherein the source access network device is configured to;

obtain a packet to send to the target access network device,

transmit the packet to a first core network device for switching to the target access network device, wherein the first core network device is selected from the plurality of core network devices based on a load balancing algorithm configured by a controller, and

transmit at least one copy of the packet to a respective second core network device for switching to the target access network device,

wherein the target access network device is configured to;

receive at least one of the packet or the at least one copy of the packet,

generate based on the receiving, at least one metric indicative of a level of traffic congestion at the first and second core network devices, and

transmit information regarding the at least one metric to the controller,

wherein the controller is configured to adjust the load balancing algorithm based on the at least one metric.

16. The communication network of claim 15, wherein the source access network device is further configured to transmit at least one subsequent packet based on the adjusted load balancing algorithm.

17. The communication network of claim 15, further comprising:

a source end point device coupled to the source access network device; and

a target end point device coupled to the target access network device,

wherein the source access network device is further configured to receive the packet from a source end point device for transmitting to the target end point device.

18. The communication network of claim 17, wherein, after the recording, the target access network device is configured to forward one of the packet or the at least one copy of the packet to the target end point device and discard the other packet.

19. The communication network of claim 15, wherein the packet is part of operations, administration and maintenance (OAM) traffic.

20. An apparatus for switching data in a communication network, comprising:

means for obtaining at a source access network device a packet to send to a target access network device, wherein each of the source access network device and the target access network device is coupled to each of a plurality of core network devices;

means for transmitting by the source access network device the packet to a first core network device for switching to the target access network device, wherein the first core network device is selected from the plurality of core network devices based on a load balancing algorithm configured by a controller;

means for transmitting by the source access network device at least one copy of the packet to a respective second core network device for switching to the target access network device;

means for receiving at the target access network device at least one of the packet or the at least one copy of the packet;

means for generating by the target access network device based on the receiving, at least one metric indicative of a level of traffic congestion at the first and second core network devices;

means for transmitting by the target access network device information regarding the at least one metric to the controller; and

means for adjusting by the controller the load balancing algorithm based on the at least one metric.