IMPLEMENTATION OF A QoS PROCESSING FILTER TO MANAGE UPSTREAM OVER-SUBSCRIPTION

• US 20120218894A1
• Filed: 02/28/2011
• Published: 08/30/2012
• Est. Priority Date: 02/28/2011
• Status: Active Grant

• Current Assignee: Extreme Networks, Inc.
• Original Assignee: Avaya Incorporated
• Inventors: Assarpour, Hamid, Mindlin, Olga
• Granted Patent: US 8,824,293 B2
• Time in Patent Office: Days
• US Class Current: 370/235
• CPC Class Codes: H04L 49/205 Quality of Service based
• CPC Class Codes: H04L 49/65 Re-configuration of fast packet switches

Abstract

A switch device can be configured to operate in a manner that was not originally intended. For example, a switch device can be a Broadcom XGS type of device that is configured with a packet-processing unit to perform line speed lookups in accordance with a default configuration. The default configuration can include classifying and forwarding received packets to an upstream interface based on VLAN information. The default configuration can be overwritten such that the switch device operates in a different manner than originally intended. For example, the switch device can be reconfigured to include mapping rules that specify different QoS data to be assigned to different type of received packets. Subsequent to utilizing the maps to identify QoS information for received packets, the reconfigured switch device uses the QoS information to forward the packets to queues in an upstream interface.

Claims

1. A method of implementing a packet processing unit in a switch device in communication with an upstream interface that is oversubscribed on ingress, the method comprising:

in the packet processing unit;

receiving multiple packets;

utilizing at least one map to identify QoS information for each of the multiple packets;

based on the QoS information, select respective queues in which to forward the multiple packets to the upstream interface; and

forwarding the multiple packets to the selected respective queues.

2. The method as in claim 1 further comprising:

identifying the QoS information based on fast lookup pattern matching implemented by the packet processing unit.

3. The method as in claim 1 further comprising:

in the upstream interface, selectively dropping at least one of the multiple packets due to oversubscription on the ingress of the upstream interface.

4. The method as in claim 1, wherein the packet processing unit is configured to perform line speed lookups for the multiple packets.

5. The method as in claim 1 further comprising:

receiving QoS information for a given packet of the multiple packets;

detecting that the given packet is a control plane packet;

identifying alternative QoS information for the control plane packet; and

forwarding the control plane packet to the upstream interface based on the alternative QoS information.

6. The method as in claim 1 further comprising:

updating the at least one map based on received configuration information.

7. The method as in claim 1, wherein utilizing the at least one map to identify QoS information includes:

for a given packet of the multiple packets;

selecting a QoS priority level amongst multiple different QoS priority levels; and

prior to forwarding, modifying a header in the given packet to include the selected QoS priority level.

8. The method as in claim 1 further comprising:

identifying the QoS information based on fast lookup pattern matching implemented by the packet processing unit, the packet processing unit configured to perform line speed lookups for the multiple packets;

in the upstream interface, selectively dropping at least one of the multiple packets due to over subscription of packets on the ingress of the upstream interface; and

wherein utilizing the at least one map to identify QoS information includes;

for a given packet of the multiple packets;

selecting a QoS priority level amongst multiple different QoS priority levels; and

prior to forwarding to the upstream interface, modifying a header in the given packet to include the selected QoS priority level.

9. A method comprising:

receiving a switch device, the switch device including a packet processing unit to perform line speed lookups in accordance with a default configuration of the switch device;

overriding settings of the switch device to reconfigure the packet processing unit to;

receive a packet;

utilize a map to identify QoS information for the packet;

based on the QoS information, select a queue in which to forward the packet; and

forward the packet to the selected queue.

10. The method as in claim 9, wherein the switch device is an XGS type of switch device.

11. The method as in claim 9, wherein the switch device is of a type selected from the group consisting of:

Firebolt, Scorpion, and Trident types of switch devices.

12. The method as in claim 10, wherein overriding settings of the switch device includes:

configuring the packet processing unit to be a multiple-stage QoS filter in which a first stage performs line speed lookups of QoS information for received packets and a second stage selects forwarding queues in which to forward the packets based on the QoS information.

13. The method as in claim 9, wherein overriding settings of the switch device includes:

configuring the packet processing unit to include multiple lookup tables in which to map received packets to respective QoS information.

14. The method as in claim 12, wherein the default configuration of the switch device is configured to classify and forward received packets based on VLAN information.

15. A switch device comprising:

a packet processing unit, the packet processing unit in communication with an upstream interface that is oversubscribed with too many packets on ingress;

the packet processing unit in the switch device reconfigured to;

receive multiple packets;

utilize at least one map to identify QoS information for each of the multiple packets;

based on the QoS information, select respective queues in which to forward the multiple packets upstream; and

forward the multiple packets to the respective queues in the upstream interface.

16. The switch device as in claim 15, wherein the packet processing unit is configured to identifying the QoS information at substantially line rate speeds of receiving the multiple packets at the switch device.

17. The switch device as in claim 15 further comprising:

in the upstream interface, selectively dropping at least one of the multiple packets due to over subscription.

18. The switch device as in claim 15, wherein the packet processing unit is configured to:

receive QoS information for a given packet of the multiple packets;

detect that the given packet is a control plane packet;

identify alternative QoS information for the control plane packet; and

forward the control plane packet to the upstream interface based on the alternative QoS information.

19. The switch device as in claim 15, wherein the packet processing unit is configured to:

update the at least one map based on received mapping information.

20. The switch device as in claim 15, wherein the packet processing unit is configured to:

for a given packet of the multiple packets;

selecting a QoS priority level amongst multiple different QoS priority levels; and

prior to forwarding, modifying a header in the given packet to include the selected QoS priority level.