Distributed routing with centralized quality of service

• US 8,693,470 B1
• Filed: 05/03/2010
• Issued: 04/08/2014
• Est. Priority Date: 05/03/2010
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Shroff, Chirag K., Maxwell, Larus B.
• Primary Examiner(s): Phillips, Hassan
• Assistant Examiner(s): Foud, Hicham
• Application Number:
  US12/772,643
• Time in Patent Office: 1,436 Days
• Field of Search: None
• US Class Current: 370/389
• CPC Class Codes: H04L 45/302 Route determination based on requested QoS

Abstract

In one embodiment a method for routing packets includes receiving, at a first packet forwarding module, a first stream of packetized data from a first source, receiving, at a second packet forwarding module, a second stream of packetized data from a second source, wherein the second packet forwarding module is separate from the first packet forwarding module and is configured identically to the first routing forwarding module, and passing packet output from the first packet forwarding module and packet output from the second packet forwarding module to a single Quality of Service module configured to queue the packet output for egress to a network.

Claims

1. A method, comprising:

receiving, at a first packet forwarding module, a first stream of packetized data from a first source terminal;

receiving, at a second packet forwarding module, a second stream of packetized data from a second source terminal, wherein the packet forwarding module is separate from the first packet forwarding module and is configured identically to the first packet forwarding module;

generating data from the received first and second streams of packetized data that identifies egress queues for respective packets thereof;

processing respective packets from the first and second streams of packetized data into fully routable packets including a media access control (MAC) address of a next-hop destination in the network, wherein one of the fully routable packets is a control packet;

adding a header to each of the fully routable packets, the header comprising information indicative of a destination terminal to which a given packet is to be sent;

passing the fully routable packets and the data identifying the egress queues to a single Quality of Service module;

processing the control packet through the Quality of Service module and passing the control packet to a route processor module that is configured to provide routing tables to the first and second packet forwarding modules, wherein the processing includes keeping the header on the control packet when the control packet is routed to the route processor module;

removing the header from the fully routable packets that are not the control packet in the Quality of Service module;

queuing, by the Quality of Service module, the fully routable packets from which the headers have been removed in the egress queues in accordance with the data identifying the egress queues for the respective packets; and

providing the queued packets from the Quality of Service module to a network in a priority order of service associated with the respective egress queues.

2. The method of claim 1, further comprising configuring the first packet forwarding module and the second packet forwarding module from data provided by a single route processor module.

3. The method of claim 1, wherein the first packet forwarding module and the second packet forwarding module operate independently of one another.

4. The method of claim 1, further comprising loading the first packet forwarding module and the second packet forwarding module with identical forwarding information bases.

5. The method of claim 1, wherein packets in the first stream of packetized data and in the second stream of packetized data are Ethernet packets.

6. The method of claim 1, further comprising logically grouping the first and second packet forwarding modules in a first group of a plurality of packet forwarding modules and logically grouping third and fourth packet forwarding modules in a second group of a plurality of packet forwarding modules, wherein the second group of packet forwarding modules is configured differently from the first group of packet forwarding modules.

7. The method of claim 1, wherein providing the queued packets to the network comprises forwarding packets, by the Quality of Service module, from at least two egress queues to respective egress I/O devices that transmit the queued packets by different physical signal types.

8. The method of claim 7, wherein one of the physical signal types is radio and the other physical signal type is laser.

9. The method of claim 1, wherein the control packet is encrypted and the method further comprises passing the encrypted control packet from the Quality of Service module to the route processor module through a cryptographic mechanism.

10. An apparatus, comprising:

a plurality of packet forwarding modules, each being configured identically but operating independently of each other, and each configured to receive packetized data and to identify egress queues into which respective packets of the packetized data are to be queued;

a single Quality of Service module configured to receive routable packets from respective ones of the packet forwarding modules, the Quality of Service module queuing the received routable packets into the egress queues in accordance with the identification thereof in the packet forwarding modules and providing the queued packets to a network in a priority of service associated with the respective queues; and

a route processor configured to supply routing tables to the packet forwarding modules and control data to the Quality of Service module, wherein;

each packet forwarding module in the plurality of packet forwarding modules is configured to (i) generate from each of the respective packets of the packetized data a fully routable packet including a rewritten media access control (MAC) address of a next-hop destination on the network, wherein one of the fully routable packets is a control packet, and (ii) add a header, indicative of a logical interface to which the packet is to be sent, to each packet processed thereby; and

the Quality of Service module is configured to

remove the header from each fully routable packet except if the fully routable packet is the control packet before outputting each fully routable packet except the control packet to a network, and

keep the header on the control packet and pass the control packet with the header thereon to the route processor.

11. The apparatus of claim 10, further comprising a distributor configured to pass selected streams of the packetized data to selected ones of the packet forwarding modules based on a source from which the respective streams of packetized data are received.

12. An apparatus, comprising:

a first logical group of packet forwarding modules, each of the packet forwarding modules in the first logical group being configured identically in accordance with a common functional role, and each being configured to receive packetized data and to identify egress queues into which respective packets of the packetized data are to be queued;

a second logical group of packet forwarding modules, each of the packet forwarding modules in the second logical group being configured identically in accordance with another common functional role, and each being configured to receive packetized data and to identify the egress queues into which respective packets of the packetized data are to be queued, wherein the packet forwarding modules in the first logical group are configured differently from the packet forwarding modules in the second logical group in accordance with a routing domain of the corresponding first and second logical groups; and

a single Quality of Service module configured to receive all packets processed by each of the packet forwarding modules in both the first and second logical groups, the Quality of Service module further being configured to control which packets processed by the packet forwarding modules in both the first and second logical groups are given priority, wherein;

each packet forwarding module in the first and second logical groups of packet forwarding modules is configured to (i) generate from each of the respective packets of the packetized data a fully routable packet including a rewritten media access control (MAC) address of a next-hop destination on the network, wherein one of the fully routable packets is a control packet, and (ii) add a header, indicative of a logical interface to which the packet is to be sent, to each packet processed thereby; and

the Quality of Service module is configured to

remove the header from each fully routable packet except if the fully routable packet is the control packet before outputting each fully routable packet except the control packet to a network, and

keep the header on the control packet and pass the control packet with the header thereon to the route processor.

13. The apparatus of claim 12, further comprising a route processor configured to provide routing tables to each of the packet forwarding modules in both the first and second logical groups and to provide control information to the Quality of Service module.