Method for traffic management, traffic prioritization, access control, and packet forwarding in a datagram computer network

• US 6,798,776 B1
• Filed: 01/14/2000
• Issued: 09/28/2004
• Est. Priority Date: 12/29/1995
• Status: Expired due to Fees

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Bechtolsheim, Andreas V., Cheriton, David R.
• Primary Examiner(s): Jung, Min
• Application Number:
  US09/482,940
• Time in Patent Office: 1,719 Days
• Field of Search: 370/392, 370/395.31, 370/395.32, 370/396, 370/397, 370/398, 370/399, 370/465, 709/238, 709/242
• US Class Current: 370/392
• CPC Class Codes: H04L 12/4608 LAN interconnection over ATM networks
• CPC Class Codes: H04L 12/4645 Details on frame tagging routing of packets H04L45/00; support for virtual LAN H04L49/354

Abstract

A method and apparatus for an enhanced datagram packet switched computer network is disclosed. The invention processes network datagram packets in network devices as separate flows, based on the source-destination address pair contained in the datagram packet itself. As a result, the network can control and manage each flow of datagrams in a segregated fashion. The processing steps that can be specified for each flow include traffic management, flow control, packet forwarding, access control, and other network management functions. The ability to control network traffic on a per flow basis allows for the efficient handling of a wide range and a large variety of network traffic, as is typical in large-scale computer networks, including video and multimedia type traffic. The amount of buffer resources and bandwidth resources assigned to each flow can be individually controlled by network management. In the dynamic operation of the network, these resources can be varied based on actual network traffic loading and congestion encountered.

Claims

1. In a network device, a method for processing a plurality of datagram packets each including a source-destination address pair, comprising:

(a) comparing said source-destination address pair contained in each respective datagram packet to a stored listing of source-destination pairs, each source-destination pair in the listing being associated with a virtual path;

(b) if no match is found in the comparing for a currently compared respective datagram packet, creating and storing a virtual path for the source-destination pair of that currently compared respective datagram packet; and

(c) if a match is found in the comparing for the currently compared respective datagram packet, processing the currently compared respective datagram packet based on the stored virtual path.

2. The method of claim 1, wherein each datagram packet further includes a type field and the processing is determined by the source-destination address pair and the type field contained in each datagram packet.

3. The method of claim 1, wherein each datagram packet is one of datagrams defined in the IEEE 802 family of network standards.

4. The method of claim 1, wherein each datagram packet is an Ethernet datagram packet and wherein the source address is the Ethernet packet source address field and the destination address is the Ethernet packet destination address field.

5. The method of claim 1, wherein the processing comprises an action chosen from the group consisting of:

dropping the packet, buffering the packet, forwarding the packet to an output port, forwarding the packet to a multiplicity of output ports, forwarding a copy of the packet to another network device, and generating a response back to the sender of the packet.

6. The method of claim 1, wherein the processing includes forwarding respective of the datagram packets to an output port.

7. The method of claim 1, wherein the processing includes forwarding respective of the datagram packets to a multiplicity of output ports.

8. The method of claim 1, wherein the processing includes sending respective of the datagram packets to a controller CPU for further processing.

9. The method of claim 1, wherein the processing includes forwarding a copy of respective of the datagram packets to another network device for processing.

10. The method of claim 1, wherein the processing includes discarding respective of the datagram packets.

11. The method of claim 1, wherein the processing includes notifying the sender of respective of the datagram packets that the respective datagram packets that were sent have not been accepted.

12. The method of claim 1, wherein the processing includes notifying the sender of respective of the datagram packets that the respective datagram packets that were sent have not been accepted, wherein said datagram is an Ethernet datagram, and wherein the response back to the source comprises an Ethernet collision signal.

13. The method of claim 1, wherein the processing includes determining whether respective of the datagram packets are sent from an authorized source to an authorized destination.

14. The method of claim 1, wherein the processing includes storing respective of the datagram packets in packet buffer memory, with separate buffer resources provided for each separate virtual path.

15. The method of claim 1, wherein the processing includes determining availability of buffer space on a particular virtual path and not accepting additional datagram packets that would exceed an amount of buffer space allowed for the particular virtual path.

16. The method of claim 1, wherein the processing includes communicating availability of packet buffer resources available to an upstream sender of datagram packets.

17. The method of claim 1, further comprising (c) allowing the network device to specify a maximum rate of transmission of a flow of datagrams.

18. The method of claim 1, further comprising (c) providing for specifying a rate of transmission of one flow of datagrams packets relative to a rate of transmission of other flows of datagram packets.

19. In a network device, a method for processing datagram packets each having a source and a destination address, comprising:

(a) receiving respective of the datagram packets;

(b) determining from the source-destination address pair contained in each of the datagram packets a virtual path record comprising specifications for processing the respective datagram packets by comparing source-destination address pairs in each of the respective datagram packets with a stored list of source-destination address pairs, each source-destination address pair associated with a respective datagram packet, wherein in the comparing (b1) if no match is found in the comparing for a currently compared respective datagram packet, a virtual path for the source-destination pair of that currently compared respective datagram packet is created and stored and (b2) if a match is found in the comparing for the currently compared respective datagram packet, the respective datagram packets is processed according to the processing steps associated with said virtual path record.

20. A network device, comprising:

(a) at least one port configured to receive and transmit datagram packets, each including a source-destination address pair;

(b) a memory configured to store said datagram packets; and

(c) a processor configured to compare said source-destination address pair contained in each of the datagram packets to a listing of source-destination pairs, each source-destination pair in the listing being associated with a virtual path, and

(c1) if no match is found in the comparing for a currently compared respective datagram packet, a virtual path for the source-destination pair of that currently compared respective datagram packet is created and stored in the memory; and

(c2) if a match is found in the comparing for the currently compared respective datagram packet, the currently compared respective datagram packet is processed based on the stored virtual path.

21. A network device as in claim 20, wherein said at least one port comprises a plurality of ports.

22. A network device as in claim 20, wherein said processing defines an action to be taken with respect to each datagram packet, said action being chosen from the group consisting of:

dropping the packet, buffering the packet, forwarding the packet to an output port, forwarding the packet to a multiplicity of output ports, forwarding a copy of the packet to another network device, and generating a response back to the sender of the packet.

23. The network device of claim 20, wherein each datagram packet is one of datagrams defined in the IEEE 802 family of network standards.

24. The network device of claim 20, wherein each datagram packet is an Ethernet datagram packet and wherein the source address is the Ethernet packet source address field and the destination address is the Ethernet packet destination address field.

25. The network device of claim 20, wherein the processor processes each datagram packet comprises a routing action chosen from the group consisting of:

dropping the packet, buffering the packet, forwarding the packet to an output port, forwarding the packet to a multiplicity of output ports, forwarding a copy of the packet to another network device, and generating a response back to the sender of the packet.

26. The network device of claim 20, further comprising means for storing information specifying an amount of buffer resources provided for each separate flow of datagram packets.

27. The network device of claim 20, further comprising flow control means for communicating to an upstream sender of datagram packets availability of packet buffer resources available.

28. The network device of claim 20, further comprising means for allowing the network system to control relative rate of transmissions among multiple flows of datagram packets.

29. The network device of claim 20, further comprising:

a virtual path cache memory for providing storage for most recently used virtual path records;

virtual path cache lookup means for allowing switch hardware to determine if a certain virtual path entry is located in the virtual path cache;

means for performing processing actions specified in the virtual path record if a valid virtual path record is found in the virtual path cache memory; and

means for processing datagram packets for which no valid entry is found in the virtual path cache memory.

30. The network device of claim 29, further comprising a controller CPU and controller memory for processing datagram packets that have no valid virtual path record in the virtual path cache, said controller CPU also being able to read and write virtual path cache entries.