METHOD AND APPARATUS FOR EFFICIENTLY PROCESSING DATA PACKETS IN A COMPUTER NETWORK

• US 20070208876A1
• Filed: 05/07/2007
• Published: 09/06/2007
• Est. Priority Date: 05/06/2002
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Foundry Networks LLC (Broadcom, Inc.)
• Inventors: Davis, Ian
• Granted Patent: US 8,671,219 B2
• Time in Patent Office: Days
• US Class Current: 709/240
• CPC Class Codes: H04L 12/4645 Details on frame tagging routing of packets H04L45/00; support for virtual LAN H04L49/354
• 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
• CPC Class Codes: H04L 47/2433 Allocation of priorities to traffic types
• CPC Class Codes: H04L 47/2458 Modification of priorities while in transit

Abstract

According to an embodiment of the invention, a network device such as a router or switch provides efficient data packet handling capability. The network device includes one or more input ports for receiving data packets to be routed, as well as one or more output ports for transmitting data packets. The network device includes an integrated port controller integrated circuit for routing packets. The integrated circuit includes an interface circuit, a received packets circuit, a buffer manager circuit for receiving data packets from the received packets circuit and transmitting data packets in one or more buffers and reading data packets from the one or more buffers. The integrated circuit also includes a rate shaper counter for storing credit for a traffic class, so that the integrated circuit can support input and/or output rate shaping. The integrated circuit may be associated with an IRAM, a CAM, a parameter memory configured to hold routing and/or switching parameters, which may be implemented as a PRAM, and an aging RAM, which stores aging information. The aging information may be used by a CPU coupled to the integrated circuit via a system interface circuit to remove entries from the CAM and/or the PRAM when an age count exceeds an age limit threshold for the entries.

Claims

1. A method of assigning priority to a data packet, comprising:

setting a default priority for the data packet; and

modifying the default priority in accordance with packet information specified in the data packet.

2. A method as in claim 1, wherein the packet information used in modifying the default priority relates to a VLAN priority.

3. A method as in claim 1, wherein the packet information used in modifying the default priority relates to a TOS priority.

4. A method as in claim 1, wherein the packet information used in modifying the default priority comprises the greater of a VLAN priority and a TOS priority.

5. The method of claim 1, wherein said port default priority is port-based.

6. The method of claim 1, further comprising providing a merge number from a packet evaluation of said data packet.

7. The method of claim 1, wherein said packet evaluation comprises performing a CAM lookup.

8. The method of claim 7, wherein said packet evaluation comprises accessing a parameter in a parameter memory, said parameter chosen from the group consisting of a switching parameter and a routing parameter.

9. The method of claim 7, further comprising determining a final packet priority based on said first priority and said merge number.