Scaleable and robust solution for reducing complexity of resource identifier distribution in a large network processor-based system

• US 6,473,434 B1
• Filed: 04/20/2001
• Issued: 10/29/2002
• Est. Priority Date: 04/20/2001
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Araya, Yonas, Gorti, Brahmanand Kumar, Basso, Claude
• Primary Examiner(s): LUTHER, WILLIAM A
• Application Number:
  US09/838,916
• Publication Number:
  US 20020154648A1
• Time in Patent Office: 557 Days
• Field of Search: 370/412, 370/414, 370/413, 370/415, 370/416, 370/417, 370/418, 370/428, 370/463, 370/419, 370/429, 370/912, 370/398, 370/395.1, 370/351, 370/386, 709/215, 709/216, 709/201, 709/103, 709/102, 709/106, 709/300, 710/39, 710/54, 710/129
• US Class Current: 370/412
• CPC Class Codes: H04L 47/10 Flow control; Congestion control
• CPC Class Codes: H04L 47/2408 for supporting different services, e.g. a differentiated services [DiffServ] type of service

Abstract

In a router comprising one or more network processing (NP) devices for routing data packets from a source NP device to a destination device via a switch fabric, with each network processing device supporting a number of interface ports, each port capable of interfacing with one or more data queues for receiving packets associated with a class-of-service characterizing the routing of the packets, a system and method for routing packets comprising: classifying a packet to be forwarded from a source NP device according to a particular class-of-service and determining outgoing interface port information of a destination NP device to forward the packet, the interface port having a pre-defined queue base address associated therewith; encoding a queue index offset for the packet associated with a particular class-of-service associated with the packet to be routed; forwarding the packet, queue index offset and outgoing interface port information to the destination NP; and, determining a queue identifier from the base address and transmitted queue index offset for indicating a particular queue by which the classified packet is to be forwarded, wherein the queue identifier is determined locally at the destination NP device forwarding the packet.

Claims

1. In a router comprising one or more network processing (NP) devices for routing data packets from a source NP device to a destination device via a switch fabric, with each network processing device supporting a number of interface ports, each port capable of interfacing with one or more data queues for receiving packets associated with a class-of-service characterizing said routing of said packets, a method for routing packets comprising:

a) classifying a packet to be forwarded from a source NP device according to a particular class-of-service and determining outgoing interface port information of a destination NP device to forward said packet, said interface port having a pre-defined queue base address associated therewith;

b) encoding a queue index offset for said packet associated with a particular class-of-service associated with said packet to be routed;

c) forwarding said packet, queue index offset and outgoing interface port information to said destination NP; and

,

d) determining a queue identifier from said base address and transmitted queue index offset for indicating a particular queue by which said classified packet is to be forwarded, wherein said queue identifier being determined locally at the destination NP device forwarding the packet.

2. The method in accordance with claim 1, further including the step e) of placing the forwarded packet in the particular queue corresponding to said calculated queue identifier.

3. The method in accordance with claim 1, further including the step of implementing a control mechanism for assigning one or more class-of-service queue control blocks for each interface port.

4. The method in accordance with claim 1, further including, prior to step a), the step of assigning a queue base address to each interface port supported by NP devices in said router.

5. The method in accordance with claim 1, wherein said encoding step b) includes the step of mapping class-of-service information conveyed by a control mechanism to a queue index.

6. The method in accordance with claim 1, wherein said forwarding step c) includes the step of enqueuing the packet to a switch in said switch fabric prior to forwarding it to said destination NP with said queue index offset and interface port information.

7. A router comprising one or more network processing (NP) devices for routing data packets from a source NP device to a destination device via a switch fabric, each network processing device including a means capable of interfacing with one or more data queues, each data queue associated with a packet flow for receiving packets associated with a class-of-service characterizing treatment of packets comprising said packet flow, said router comprising:

device located at a source NP device for classifying a packet to be routed according to a particular class-of-service, and determining outgoing interface information of a destination NP device handling said packet flow, one of said destination NP device interface means or packet flow having a pre-defined queue base address associated therewith;

device for encoding a queue index offset for said packet according to a particular class-of-service characterizing said packet flow;

forwarding mechanism for transmitting said packet, queue index offset and outgoing interface information to said destination NP; and

,

mechanism for determining a queue identifier from said queue base address and transmitted queue index offset, said queue identifier for indicating a particular queue to receive said classified packet, wherein said queue identifier is determined locally at the destination NP device forwarding the packet.

8. The router as claimed in claim 7, wherein an interface means supported at said destination NP device includes a port device.

9. The router as claimed in claim 7, wherein said forwarding mechanism further places the forwarded packet in the particular queue corresponding to said determined queue identifier.

10. The router as claimed in claim 8, further including a control device for assigning one or more class-of-service queue control blocks corresponding to a port device.

11. The router as claimed in claim 10, wherein said control device further assigns said queue base address to each port device supported by NP devices in said router.

12. The router as claimed in claim 7, wherein said encoding device performs a mapping of class-of-service information conveyed by said control device to a queue index.

13. The router as claimed in claim 7, wherein said forwarding mechanism further enqueues the packet to a switch in said switch fabric prior to forwarding it to said destination NP with said queue index offset and outgoing interface information.

14. In a router comprising one or more network processing (NP) devices for routing data packets from a source NP device to a destination device via a switch fabric, with each network processing device including a means capable of interfacing with one or more data queues, each DATA QUEUE with a packet flow for receiving packets associated with a class-of-service characterizing treatment of packets comprising said packet flow, a method for routing packets comprising:

a) classifying a packet to be forwarded from a source NP device according to a particular packet flow and determining outgoing interface information of a destination NP device handling said packet flow, one of said destination NP device interface means or packet flow having a pre-defined queue base address associated therewith;

b) encoding a queue index offset for said packet according to a particular class-of-service characterizing said packet flow;

c) forwarding said packet, queue index offset and outgoing interface information to said destination NP; and

,

d) determining a queue identifier from said base address and transmitted queue index offset for indicating a particular queue to receive said classified packet, wherein said queue identifier is determined locally at the destination NP device forwarding the packet.

15. The method as claimed in claim 14, wherein an interface means supported at said destination NP device includes a port device.