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

• US 6,091,725 A
• Filed: 12/29/1995
• Issued: 07/18/2000
• Est. Priority Date: 12/29/1995
• Status: Expired due to Term

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Systems, Inc.
• Inventors: Cheriton, David R., Bechtolsheim, Andreas V.
• Primary Examiner(s): Jung, Min
• Application Number:
  US08/581,134
• Time in Patent Office: 1,663 Days
• Field of Search: 370/230, 370/231, 370/235, 370/236, 370/237, 370/395, 370/392, 370/397, 370/401, 370/402, 370/403, 370/412, 370/399, 370/407, 370/400
• 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

The invention provides an enhanced datagram packet switched computer network. The invention processes network datagram packets in network devices as separate flows, based on the source-destination address pair in the datagram packet. 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 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. The invention also teaches an enhanced datagram packet switched computer network which can selectively control flows of datagram packets entering the network and traveling between network nodes. This new network access control method also interoperates with existing media access control protocols, such as used in the Ethernet or 802.3 local area network. An aspect of the invention is that it does not require any changes to existing network protocols or network applications.

Claims

1. A method for operating a packet switching network wherein forwarding is done in a hop-by-hop manner, said network including a plurality of stations, each station having a table of routing information, one or more output ports and one or more input ports, said method comprising the steps of:

for each station in the network, upon arrival of a packet to any station, a header of said packet containing a source address and a destination address, performing the steps of;

routing said packet to a second station that is directly linked to said one station by performing the steps of;

determining an output port to which to route said packet, after said arrival, in response to both said source address and said destination address, the determining step comprising,

combining said source address information and said destination address information to determine an index value,

checking said table of routing information for an entry matching said index value,

if said entry matching said index value is present, routing said packet according to said entry, and

if said entry matching said index value is not present in said table, forwarding said packet to a processor for determining routing information and routing said packet according to said routing information; and

routing the packet to said output port,

wherein said step of determining the output port to which to route said packet is performed in hardware.

2. A method as in claim 1, wherein said table is updated in response to said routing information for said source address and said destination address.

3. A method for operating a packet switching network wherein forwarding is done in a hop-by-hop manner, said network including a plurality of stations, each station having a table of routing information, one or more output ports and one or more input ports, said method comprising the steps of:

for each station in the network, upon arrival of a packet to any station, a header of said packet containing a source address and a destination address, performing the steps of;

routing said packet to a second station that is directly linked to said one station by performing the steps of;

determining an output port to which to route said packet, after said arrival, in response to both said source address and said destination address, the determining step comprising,

combining said source address information and said destination address information to determine an index value,

checking said table of routing information for an entry matching said index value,

if said entry matching said index value is present, routing said packet according to said entry, and

if said entry matching said index value is not present in said table, forwarding said packet to a processor for determining routing information and routing said packet according to said routing information; and

routing the packet to said output port.

4. A method as in claim 3, wherein said table is updated in response to said routing information for said source address and said destination address.

5. A method for operating a packet switching network wherein forwarding is done in a hop-by-hop manner, said network including a plurality of stations, each station having a table of routing information, one or more output ports and one or more input ports, said method comprising the steps of:

for each station in the network, upon arrival of a packet to any station, a header of said packet containing a source address and a destination address, performing the steps of;

routing said packet to a second station that is directly linked to said one station by performing the steps of;

determining an output port to which to route said packet, after said arrival, in response to both said source address and said destination address, the determining step comprising,

combining said source address information and said destination address information to determine an index value,

checking said table of routing information for an entry matching said index value,

if said entry matching said index value is present, routing said packet according to said entry, and

if said entry matching said index value is not present is said table, performing the following steps;

forwarding said source address and said destination address of said packet to a processor for determining a set of routing information;

communicating said routing information to said station; and

routing said packet according to said routing information; and

routing the packet to said output port.

6. A method as in claim 5, wherein said table is updated in response to said routing information for said source address and said destination address.