System for routing packets by separating packets in to broadcast packets and non-broadcast packets and allocating a selected communication bandwidth to the broadcast packets

• US 5,793,978 A
• Filed: 12/29/1994
• Issued: 08/11/1998
• Est. Priority Date: 12/29/1994
• Status: Expired due to Term

• Current Assignee: Cisco Systems, Inc.
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Fowler, Gregory Alan
• Primary Examiner(s): Lee, Thomas C.
• Assistant Examiner(s): Huang, Po C.
• Application Number:
  US08/367,509
• Time in Patent Office: 1,321 Days
• Field of Search: 395/200.31, 395/200.56, 395/200.53, 395/200.65, 395/200.66, 358/400
• US Class Current: 709/226
• CPC Class Codes: H04L 12/1886 with traffic restrictions for efficiency improvement, e.g. involving subnets or subdomains
• CPC Class Codes: H04L 47/10 Flow control; Congestion control
• CPC Class Codes: H04L 47/15 in relation to multipoint traffic arrangements for broadcast or multicast in data networks H04L12/18
• CPC Class Codes: H04L 47/16 in connection oriented networks, e.g. frame relay

Abstract

A method and system for routing packets, in which the resources consumed by broadcast packets are limited. Broadcast packets are placed in a separate queue that is managed independently of the buffer interface queue for non-broadcast packets. The broadcast queue is limited to a selected amount of communication bandwidth; when the amount of broadcast traffic exceeds the selected bandwidth, broadcast messages are queued and held for transmission until later (i.e., when the selected amount of bandwidth becomes available). An operator may specify a maximum number of broadcast packets to be sent in any one second period, an a maximum number of broadcast packet bytes to be sent in any one second period.

Claims

1. A system for routing packets, comprising:

a network interface;

a first transmit queue associated with said network interface;

a second transmit queue for queuing broadcast packets to said first transmit queue;

means for identifying a packet as a broadcast packet or a non-broadcast packet;

means, responsive to said means for identifying, for placing said packets identified as non-broadcast packets in said first transmit queue and for placing said packets identified as broadcast packets in said second transmit queue;

means for allocating a selected communication bandwidth to said broadcast packets; and

means for transferring packets from said second transmit queue to said first transmit queue responsive to said means for allocating, wherein resources occupied by said broadcast packets are limited to said selected communication bandwidth.

2. A system as in claim 1, wherein said means for placing is responsive to a clock.

3. A system as in claim 1, comprising

means for receiving an operator command;

and

means for setting a length of said second transmit queue responsive to said operator command.

4. A system as in claim 1, wherein said means for transferring is responsive to a clock.

5. A system as in claim 1, wherein said means for transferring comprises means for limiting said broadcast packets to a selected number of bytes per second.

6. A system as in claim 1, wherein said means for transferring comprises means for limiting said broadcast packets to a selected number of packets per second.

7. A system as in claim 1, wherein said means for allocating communication bandwidth operates to limit said broadcast packets to a selected total amount of communication bandwidth for said network.

8. A system as in claim 1, further comprising means for receiving a designation of communication bandwidth to be allocated to broadcast packets;

wherein said means for allocating communication bandwidth is responsive to said means for receiving.

9. A system as in claim 8, further comprising means for receiving an operator command, wherein said means for allocating communication bandwidth is responsive to said operator command.

10. A method for routing packets, comprising the steps of

identifying a packet as a broadcast packet or a non-broadcast packet;

placing said packet on a first transmit queue associated with a network interface, or on a second transmit queue for queuing broadcast packets to said first transmit queue, responsive to said step of identifying;

reading packets from said first transmit queue and transmitting said packets to said network interface;

allocating a selected communication bandwidth to said broadcast packets; and

reading packets from said second transmit queue and transferring said packets from said second transmit queue to said first transmit queue, said first transmit queue responding to said selected communication bandwidth; and

limiting resources occupied by said broadcast packets to said selected communication bandwidth.

11. A method as in claim 10, further comprising the steps of

setting a clock interrupt;

and

triggering said clock interrupt responsive to a clock;

wherein said step of transferring packets from said second transmit queue to said first transmit queue is responsive to said clock interrupt.

12. A method as in claim 10, further comprising the steps of

receiving an operator command;

and

setting a length of said second transmit queue responsive to said operator command.

13. A method as in claim 10, wherein said step of transferring from said second transmit queue to said first transmit queue comprises the step of limiting said broadcast packets to a selected number of bytes per second.

14. A method as in claim 10, wherein said step of transferring from said second transmit queue to said first transmit queue comprises the step of limiting said broadcast packets to a selected number of packets per second.

15. A system, as in claim 10, wherein said step of allocating operates to limit said broadcast packets to a selected total amount of communication bandwidth for said network.

16. A system, as in claim 10, further comprising the step of receiving a designation of communication bandwidth to be allocated to broadcast packets;

wherein said means for allocating communication bandwidth is responsive to said means for receiving.

17. A system, as in claim 16, further comprising the step of receiving an operator command, wherein said means for allocating communication bandwidth is responsive to said operator command.