System and Method of Defense Against Denial of Service of Attacks

• US 20080212469A1
• Filed: 03/03/2008
• Published: 09/04/2008
• Est. Priority Date: 03/02/2007
• Status: Active Grant

• Current Assignee: ADVA Optical Networking SE (ADTRAN Holdings, Inc.)
• Original Assignee: ADVA Optical Networking SE (ADTRAN Holdings, Inc.)
• Inventors: Sankey, Wayne Robert, Woehler, Ralf
• Granted Patent: US 8,027,252 B2
• Time in Patent Office: Days
• US Class Current: 370/230
• CPC Class Codes: H04L 47/10 Flow control; Congestion control
• CPC Class Codes: H04L 47/2433 Allocation of priorities to traffic types
• CPC Class Codes: H04L 47/2441 relying on flow classification, e.g. using integrated services [IntServ]
• CPC Class Codes: H04L 47/29 using a combination of thresholds
• 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 47/6215 Individual queue per QOS, rate or priority
• CPC Class Codes: H04L 49/90 Buffering arrangements

Abstract

A system and method comprise a first buffer having a first capacity and a first threshold level adapted to store data frames having the lowest priority, a second buffer having a second capacity greater than the first capacity and a second threshold level greater than the first threshold level adapted to store data frames having a medium priority, a third buffer having a third capacity greater than the second capacity and a third threshold level greater than the second threshold level adapted to store data frames having the highest priority. The system further includes means for differentiating a data frame as having lowest, medium or highest priority and storing the data frame in the respective first, second or third buffer, and discarding the data frame in response to the first, second or third buffer reaching the respective threshold level.

Claims

1. A system comprising:

a transmission buffer having a first threshold level for data frames having the lowest priority, a second threshold level greater than the first threshold level for data frames having a medium priority, and a third threshold level greater than the second threshold level for data frames having the highest priority; and

means for differentiating a data frame as having lowest, medium or highest priority and storing the data frame in the transmission buffer in response to the respective threshold levels not being reached, and discarding the data frame in response to reaching the respective threshold levels.

2. The system of claim 1, wherein the transmission buffer comprises:

a first buffer having a first capacity and the first threshold level adapted to store data frames having the lowest priority;

a second buffer having a second capacity greater than the first capacity and the second threshold level greater than the first threshold level adapted to store data frames having a medium priority; and

a third buffer having a third capacity greater than the second capacity and the third threshold level greater than the second threshold level adapted to store data frames having the highest priority.

3. The system of claim 2, wherein the first buffer is adapted to store general broadcast data frames, and the third buffer is adapted to store network management data frames and routing protocol data frames.

4. The system of claim 2, wherein the third buffer is adapted to store data frames destined for a network processor.

5. The system of claim 1, where means for differentiating a data frame comprises backpressure means for handling data frames having the highest priority in response to reaching the highest threshold value.

6. A method comprising:

receiving a data frame from a memory subsystem;

differentiating the data frame as having lowest, medium or highest priority;

storing the data frame in a transmit buffer having lowest, medium, and highest thresholds in response to the priority of the data frame and the respective threshold not being exceeded; and

discarding the data frame in response to the respective threshold of the data frame being exceeded.

7. The method of claim 6, wherein storing the data frame comprises storing the data frame in a first, second or third buffer in response to the priority of the data frame and the respective threshold of the respective buffer not being exceeded.

8. The method of claim 6, wherein differentiating the data frame comprises determining whether the data frame is a general broadcast data frame having the lowest priority.

9. The method of claim 6, wherein differentiating the data frame comprises determining whether the data frame is a routing protocol data frame having the highest priority.

10. The method of claim 6, wherein differentiating the data frame comprises determining whether the data frame is destined for a network processor indicating the data frame has the highest priority.

11. The method of claim 6, further comprising exerting backpressure against the memory subsystem in response to the highest threshold being reached.

12. A computer-readable medium having encoded thereon a method, comprising:

receiving a data frame from a computer network;

differentiating the data frame as having lowest, medium or highest priority;

storing the data frame in a transmit buffer having lowest, medium, and highest thresholds in response to the priority of the data frame and the respective threshold not being exceeded; and

discarding the data frame in response to the respective threshold of the data frame being exceeded.

13. The computer-readable medium of claim 12, wherein storing the data frame comprises storing the data frame in a first, second or third buffer in response to the priority of the data frame and the respective threshold of the respective buffer not being exceeded.

14. The computer-readable medium of claim 12, wherein differentiating the data frame comprises determining whether the data frame is a general broadcast data frame having the lowest priority.

15. The computer-readable medium of claim 12, wherein differentiating the data frame comprises determining whether the data frame is a routing protocol data frame having the highest priority.

16. The computer-readable medium of claim 12, wherein differentiating the data frame comprises determining whether the data frame is destined for a network processor indicating the data frame has the highest priority.

17. The computer-readable medium of claim 12, further comprising exerting backpressure against the memory subsystem in response to the highest threshold being reached.