METHOD FOR SCORING QUEUED FRAMES FOR SELECTIVE TRANSMISSION THROUGH A SWITCH

• US 20080225859A1
• Filed: 03/19/2008
• Published: 09/18/2008
• Est. Priority Date: 01/12/1999
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Mcdata Corporation (Broadcom, Inc.)
• Inventors: Mitchem, W. Jeffrey, O'Donnell, Michael E.
• Granted Patent: US 7,848,253 B2
• Time in Patent Office: Days
• US Class Current: 370/395.21
• CPC Class Codes: H04L 47/2433 Allocation of priorities to traffic types
• CPC Class Codes: H04L 47/50 Queue scheduling
• CPC Class Codes: H04L 47/522 Dynamic queue service slot or variable bandwidth allocation
• CPC Class Codes: H04L 47/623 Weighted service order
• CPC Class Codes: H04L 49/205 Quality of Service based
• CPC Class Codes: H04L 49/30 Peripheral units, e.g. input or output ports
• CPC Class Codes: H04L 49/357 Fibre channel switches
• CPC Class Codes: H04Q 11/0407 using a stored programme control
• CPC Class Codes: H04Q 2213/1305 Software aspects
• CPC Class Codes: H04Q 2213/13103 Memory
• CPC Class Codes: H04Q 2213/13106 Microprocessor, CPU
• CPC Class Codes: H04Q 2213/13141 Hunting for free outlet, circuit or channel
• CPC Class Codes: H04Q 2213/13164 Traffic (registration, measurement,...)
• CPC Class Codes: H04Q 2213/13166 Fault prevention
• CPC Class Codes: H04Q 2213/13204 Protocols
• CPC Class Codes: H04Q 2213/13213 Counting, timing circuits
• CPC Class Codes: H04Q 2213/13216 Code signals, frame structure
• CPC Class Codes: H04Q 2213/1334 Configuration within the switch

Abstract

A method includes determining a priority of each of a plurality of frames, wherein the priority is a function of an initial value dependent on content of each said frame and one or more adjustment values independent of content of each said frame, and selecting the frame with the highest determined priority for transmission through the device prior to transmission of any other of the frames. A system includes a receiving port configured to receive frames and assign an initial priority to each frame, a queue configured to insert queue entries associated with received frames on the queue, each queue entry being inserted at a queue position based on the initial priority assigned to the queue entry, the queue further configured to reorder queue entries based on readjusted priorities of the queue entries; and a transmitter switch configured to transmit the frame having the highest priority before transmitting any other frame.

Claims

1. A method of selectively transmitting frames through a device, the method comprising:

determining a priority of each said frames wherein the priority is a function of an initial value dependent on content of each said frame and one or more adjustment values independent of content of each said frame; and

selecting the frame with the highest determined priority for transmission through the device prior to transmission of any other of the frames.

2. The method of claim 1 further comprising:

inserting each frame on a queue at a queue position based on the initial value; and

reordering frames on the queue based on adjustments to priorities of the frames.

3. The method of claim 1 wherein said determining a priority of each said frame comprises:

determining an initial score determined based on content of each said frame; and

adjusting the initial score with the one or more adjustment values, to generate an adjusted score representing the priority of each said frame.

4. The method of claim 1, wherein the initial value comprises a quality of service assigned to each said frame.

5. The method of claim 1, wherein the one or more adjustment values comprise a time value that is a function of the time that each said frame is stored on a queue.

6. The method of claim 5, wherein the time value comprises a weighted function of the time that each said frame is stored on a queue.

7. The method of claim 1, wherein the one or more adjustment values comprise a bandwidth allocation associated with a port that received each said frame.

8. The method of claim 4, further comprising determining the quality of service assigned to each said frame based on a portion of content in each said frame.

9. The method of claim 8, wherein determining the quality of service assigned to each said frame comprises:

comparing the portion of content of each said frame to each of a plurality of templates to identify one or more template matches;

defining one or more participation matches, wherein each participation match designates a combination of one or more template matches;

associating a quality of service with each of the one or more participation matches; and

assigning to each said frame the quality of service associated with the participation match corresponding to the one or more template matches identified for each said frame.

10. The method of claim 9, further comprising assigning a default quality of service to any of the frames for which the one or more identified template matches do not correspond to one of the combinations of template matches.

12. The method of claim 1t, further comprising:

inserting each frame on a determined queue among a plurality of queues, wherein each frame is inserted at a queue position based on the quality of service of the frame; and

reordering frames on each queue based on adjustments to the priorities of the frames.

11. A method for selectively transmitting a plurality of frames through a device, the method comprising:

determining a priority of each said frame, the priority being determined based on a combination of quality of service determined from content of each said frame and one or more other values determined independent of content of each said frame; and

selecting a frame having the highest determined priority for transmission through the device before transmission of any other of the frames.

13. The method of claim 11, further comprising:

receiving each said frame on one of a plurality of ports of the device;

in response to receiving each said frame, inserting an identifier of each said frame on a queue associated with the port that received each said frame, wherein inserting each said identifier on the queue comprises inserting each said identifier ahead of all other identifiers of frames on the queue having lesser quality of service and behind all other identifiers of frames on the queue having greater or equal quality of service; and

following passage of a selected time, for each said frame, combining said one or more other values with the quality of service of each said frame.

14. The method of claim 13, wherein one of the one or more other values is dependent upon the time that each said frame has been on the queue.

15. A system for selectively transmitting frames through a device, the system comprising:

a receiving port configured to receive frames and assign an initial priority to each frame;

a queue configured to insert queue entries associated with received frames on the queue, each queue entry being inserted at a queue position based on the initial priority assigned to the queue entry, the queue further configured to reorder queue entries based on readjusted priorities of the queue entries; and

a transmitter configured to transmit the frame having the highest priority before transmitting any other frame.

16. The system of claim 15 wherein the initial priority of each frame is adjusted based on adjustment values independent of content of the frame.

17. The system of claim 15, wherein the receiving port includes at least one comparator configured to compare selected content of each frame to a template.

18. The system of claim 17, wherein the receiving port further includes a plurality of participation groups configured to determine whether each frame matches a specified combination of templates.

19. The system of claim 18 wherein the initial priority of each frame is set to a quality of service associated with a participation group matched by the frame.