Priority based bandwidth allocation within real-time and non-real-time traffic streams

• US 20030189943A1
• Filed: 04/08/2002
• Published: 10/09/2003
• Est. Priority Date: 04/08/2002
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Kind, Andreas, Jeffries, Clark Debs, Gorti, Brahmanand Kumar, Heddes, Marco, Siegel, Michael Steven
• Granted Patent: US 7,385,997 B2
• Time in Patent Office: Days
• US Class Current: 370/412
• CPC Class Codes: H04L 47/10 Flow control; Congestion control
• CPC Class Codes: H04L 47/2416 Real-time traffic
• CPC Class Codes: H04L 47/2433 Allocation of priorities to traffic types
• CPC Class Codes: H04L 47/30 in combination with information about buffer occupancy at either end or at transit nodes
• CPC Class Codes: H04L 47/32 by discarding or delaying data units, e.g. packets or frames
• CPC Class Codes: H04L 47/50 Queue scheduling
• CPC Class Codes: H04L 47/52 by attributing bandwidth to queues
• CPC Class Codes: H04L 47/56 implementing delay-aware scheduling
• CPC Class Codes: H04L 47/6215 Individual queue per QOS, rate or priority

Abstract

A method and system for transmitting packets in a packet switching network. Packets received by a packet processor may be prioritized based on the urgency to process them. Packets that are urgent to be processed may be referred to as real-time packets. Packets that are not urgent to be processed may be referred to as non-real-time packets. Real-time packets have a higher priority to be processed than non-real-time packets. A real-time packet may either be discarded or transmitted into a real-time queue based upon its value priority, the minimum and maximum rates for that value priority and the current real-time queue congestion conditions. A non-real-time packet may either be discarded or transmitted into a non-real-time queue based upon its value priority, the minimum and maximum rates for that value priority and the current real-time and non-real-time queue congestion conditions.

Claims

1. A method for transmitting data in a network comprising the steps of:

receiving data;

determining if said received data is one of a real-time data and a non-real-time data, wherein said real-time data has a higher priority of transmission than said non-real-time data; and

inserting said received data into one of a first queue and a second queue, wherein said first queue is configured to store real-time data, wherein said second queue is configured to store non-real-time data, wherein said received data is inserted in said first queue if said received data is said real-time data, wherein said received data is inserted in said second queue if said received data is said non-real-time data.

2. The method as recited in claim 1 further comprising the step of:

selecting a next real-time data in said first queue to be transmitted if there is any real-time data stored in said first queue, wherein if there is no real-time data stored in said first queue, then the method further comprises the step of;

selecting a next non-real-time data in said second queue to be transmitted.

3. The method as recited in claim 1 further comprising the steps of:

determining a time and a value priority associated with said received data; and

directing said received data to an appropriate flow controller associated with said time and said value priority, wherein said flow controller is configured to determine whether to perform one of a discarding and a transmitting of said received data.

4. The method as recited in claim 1, wherein said first queue is configured to store real-time data associated with one or more value priorities, wherein a maximum rate of data is to be transmitted to said first queue for each value priority associated with said real-time data, wherein a sum of maximum rates of data to be transmitted to said first queue for each value priority associated with said real-time data is less than or equal to a maximum rate of data to be processed by said packet processor.

5. The method as recited in claim 1, wherein said first queue is configured to store real-time data associated with one or more value priorities, wherein a maximum rate of data is to be transmitted to said first queue for each value priority associated with said real-time data, wherein said second queue is configured to store non-real-time data associated with one or more value priorities, wherein a minimum rate of data is to be transmitted to said second queue for each value priority associated with said non-real-time data, wherein a sum of maximum rates of data to be transmitted to said first queue for each value priority associated with said real-time data plus a sum of minimum rates of data to be transmitted to said second queue for each value priority associated with said non-real-time data is less than or equal to a maximum rate of data to be processed by said packet processor.

6. The method as recited in claim 1, wherein a latency for transmitting real-time data to said first queue depends on a rate of real-time data to be transmitted to said first queue, wherein a latency for transmitting non-real-time data to said second queue depends on a rate of non-real-time data to be transmitted to said second queue and said rate of real-time data to be transmitted to said first queue.

7. A switch, comprising:

a switch fabric; and

a packet processor coupled to said switch fabric, wherein said packet processor is configured to direct data across said switch fabric to another packet processor, wherein said packet processor comprises;

a first queue configured to store real-time data; and

a second queue configured to store non-real-time data.

8. The switch as recited in claim 7, wherein said packet processor further comprises:

a flow control unit coupled to said first queue and said second queue, wherein said flow control unit comprises;

a memory unit operable for storing a computer program operable for transmitting data in a packet switching network; and

a processor coupled to said memory unit, wherein said processor, responsive to said computer program, comprises;

circuitry operable for receiving data;

circuitry operable for determining if said received data is one of a real-time data and a non-real-time data, wherein said real-time data has a higher priority of transmission than said non-real-time data; and

circuitry operable for inserting said received data into one of said first queue and said second queue, wherein said received data is inserted in said first queue if said received data is said real-time data, wherein said received data is inserted in said second queue if said received data is said non-real-time data.

9. The switch as recited in claim 8, wherein said packet processor further comprises:

a scheduler coupled to said first and said queue, wherein said scheduler is configured to select a next real-time data in said first queue to be transmitted if there is any real-time data stored in said first queue, wherein if there is no real-time data stored in said first queue, then said scheduler is configured to select a next non-real-time data in said second queue to be transmitted.

10. The switch as recited in claim 8, wherein said processor further comprises:

circuitry operable for determining a time and a value priority associated with said received data; and

circuitry operable for directing said received data to an appropriate flow controller associated with said time and said value priority, wherein said flow controller is configured to determine whether to perform one of a discarding and a transmitting of said received data.

11. The switch as recited in claim 8, wherein said first queue is configured to store real-time data associated with one or more priorities, wherein a maximum rate of data is to be transmitted to said first queue for each value priority associated with said real-time data, wherein a sum of maximum rates of data to be transmitted to said first queue for each value priority associated with said real-time data is less than or equal to a maximum rate of data to be processed by said packet processor.

12. The switch as recited in claim 8, wherein said first queue is configured to store real-time data associated with one or more priorities, wherein a maximum rate of data is to be transmitted to said first queue for each value priority associated with said real-time data, wherein said second queue is configured to store non-real-time data associated with one or more priorities, wherein a minimum rate of data is to be transmitted to said second queue for each value priority associated with said non-real-time data, wherein a sum of maximum rates of data to be transmitted to said first queue for each value priority associated with said real-time data plus a sum of minimum rates of data to be transmitted to said second queue for each value priority associated with said non-real-time data is less than or equal to a maximum rate of data to be processed by said packet processor.

13. The switch as recited in claim 8, wherein a latency for transmitting real-time data to said first queue depends on a rate of real-time data to be transmitted to said first queue, wherein a latency for transmitting non-real-time data to said second queue depends on a rate of non-real-time data to be transmitted to said second queue and said rate of real-time data to be transmitted to said first queue.

14. The switch as recited in claim 7, wherein said packet processor further comprises:

a flow control unit coupled to said first queue and said second queue, wherein said flow control unit is configured to receive data, wherein said flow control unit is further configured to determine if said received data is one of a real-time data and a non-real-time data, wherein said real-time data has a higher priority of transmission than said non-real-time data, wherein said flow control unit is further configured to insert said received data into one of said first queue and said second queue, wherein said received data is inserted in said first queue if said received data is said real-time data, wherein said received data is inserted in said second queue if said received data is said non-real-time data.

15. The switch as recited in claim 14, wherein said packet processor further comprises:

a scheduler coupled to said first and second queue, wherein said scheduler is configured to select a next real-time data in said first queue to be transmitted if there is any real-time data stored in said first queue, wherein if there is no real-time data stored in said first queue, then said scheduler is configured to select a next non-real-time data in said second queue to be transmitted.

16. The switch as recited in claim 14, wherein said flow control unit is further configured to determine a time and a value priority associated with said received data, wherein said flow control unit is further configured to direct said received data to an appropriate flow controller associated with said time and said value priority, wherein said flow controller is further configured to determine whether to perform one of a discarding and a transmitting of said received data.

17. The switch as recited in claim 14, wherein said first queue is configured to store real-time data associated with one or more priorities, wherein a maximum rate of data is to be transmitted to said first queue for each value priority associated with said real-time data, wherein a sum of maximum rates of data to be transmitted to said first queue for each value priority associated with said real-time data is less than or equal to a maximum rate of data to be processed by said packet processor.

18. The switch as recited in claim 14, wherein said first queue is configured to store real-time data associated with one or more priorities, wherein a maximum rate of data is to be transmitted to said first queue for each value priority associated with said real-time data, wherein said second queue is configured to store non-real-time data associated with one or more priorities, wherein a minimum rate of data is to be transmitted to said second queue for each value priority associated with said non-real-time data, wherein a sum of maximum rates of data to be transmitted to said first queue for each value priority associated with said real-time data plus a sum of minimum rates of data to be transmitted to said second queue for each value priority associated with said non-real-time data is less than or equal to a maximum rate of data to be processed by said packet processor.

19. The switch as recited in claim 14, wherein a latency for transmitting real-time data to said first queue depends on a rate of real-time data to be transmitted to said first queue, wherein a latency for transmitting non-real-time data to said second queue depends on a rate of non-real-time data to be transmitted to said second queue and said rate of real-time data to be transmitted to said first queue.

20. A packet processor, comprising:

a first queue configured to store real-time data;

a second queue configured to store non-real-time data; and

a flow control unit coupled to said first queue and said second queue, wherein said flow control unit is configured to receive data, wherein said flow control unit is further configured to determine if said received data is one of a real-time data and a non-real-time data, wherein said real-time data has a higher priority of transmission than said non-real-time data, wherein said flow control unit is further configured to insert said received data into one of said first queue and said second queue, wherein said received data is inserted in said first queue if said received data is said real-time data, wherein said received data is inserted in said second queue if said received data is said non-real-time data.

21. The packet processor as recited in claim 20 further comprises:

a scheduler coupled to said first and second queue, wherein said scheduler is configured to select a next real-time data in said first queue to be transmitted if there is any real-time data stored in said first queue, wherein if there is no real-time data stored in said first queue, then said scheduler is configured to select a next non-real-time data in said second queue to be transmitted.

22. The packet processor as recited in claim 20, wherein said flow control unit is further configured to determine a time and a value priority associated with said received data, wherein said flow control unit is further configured to direct said received data to an appropriate flow controller associated with said time and said value priority, wherein said flow controller is further configured to determine whether to perform one of a discarding and a transmitting of said received data.

23. The packet processor as recited in claim 20, wherein said first queue is configured to store real-time data associated with one or more priorities, wherein a maximum rate of data is to be transmitted to said first queue for each value priority associated with said real-time data, wherein a sum of maximum rates of data to be transmitted to said first queue for each value priority associated with said real-time data is less than or equal to a maximum rate of data to be processed by said packet processor.

24. The packet processor as recited in claim 20, wherein said first queue is configured to store real-time data associated with one or more priorities, wherein a maximum rate of data is to be transmitted to said first queue for each value priority associated with said real-time data, wherein said second queue is configured to store non-real-time data associated with one or more priorities, wherein a minimum rate of data is to be transmitted to said second queue for each value priority associated with said non-real-time data, wherein a sum of maximum rates of data to be transmitted to said first queue for each value priority associated with said real-time data plus a sum of minimum rates of data to be transmitted to said second queue for each value priority associated with said non-real-time data is less than or equal to a maximum rate of data to be processed by said packet processor.

25. The packet processor as recited in claim 20, wherein a latency for transmitting real-time data to said first queue depends on a rate of real-time data to be transmitted to said first queue, wherein a latency for transmitting non-real-time data to said second queue depends on a rate of non-real-time data to be transmitted to said second queue and said rate of real-time data to be transmitted to said first queue.

26. A computer program product embodied in a machine readable medium for transmitting data in a network comprising the programming steps of:

receiving data;

determining if said received data is one of a real-time data and a non-real-time data, wherein said real-time data has a higher priority of transmission than said non-real-time data; and

inserting said received data into one of a first queue and a second queue, wherein said first queue is configured to store real-time data, wherein said second queue is configured to store non-real-time data, wherein said received data is inserted in said first queue if said received data is said real-time data, wherein said received data is inserted in said second queue if said received data is said non-real-time data.

27. The computer program product as recited in claim 26 further comprising the programming step of:

selecting a next real-time data in said first queue to be transmitted if there is any real-time data stored in said first queue, wherein if there is no real-time data stored in said first queue, then the computer program product further comprises the programming step of;

selecting a next non-real-time data in said second queue to be transmitted.

28. The computer program product as recited in claim 26 further comprising the programming steps of:

determining a time and a value priority associated with said received data; and

directing said received data to an appropriate flow controller associated with said time and said value priority, wherein said flow controller is configured to determine whether to perform one of a discarding and a transmitting of said received data.

29. The computer program product as recited in claim 26, wherein said first queue is configured to store real-time data associated with one or more value priorities, wherein a maximum rate of data is to be transmitted to said first queue for each value priority associated with said real-time data, wherein a sum of maximum rates of data to be transmitted to said first queue for each value priority associated with said real-time data is less than or equal to a maximum rate of data to be processed by said packet processor.

30. The computer program product as recited in claim 26, wherein said first queue is configured to store real-time data associated with one or more value priorities, wherein a maximum rate of data is to be transmitted to said first queue for each value priority associated with said real-time data, wherein said second queue is configured to store non-real-time data associated with one or more value priorities, wherein a minimum rate of data is to be transmitted to said second queue for each value priority associated with said non-real-time data, wherein a sum of maximum rates of data to be transmitted to said first queue for each value priority associated with said real-time data plus a sum of minimum rates of data to be transmitted to said second queue for each value priority associated with said non-real-time data is less than or equal to a maximum rate of data to be processed by said packet processor.

31. The computer program product as recited in claim 26, wherein a latency for transmitting real-time data to said first queue depends on a rate of real-time data to be transmitted to said first queue, wherein a latency for transmitting non-real-time data to said second queue depends on a rate of non-real-time data to be transmitted to said second queue and said rate of real-time data to be transmitted to said first queue.