Pre-emption mechanism for packet transport

• US 20060109864A1
• Filed: 11/24/2004
• Published: 05/25/2006
• Est. Priority Date: 11/24/2004
• Status: Active Grant

• Current Assignee: Intel Germany GmbH (Intel Corporation)
• Original Assignee: Infineon Technologies North America Corporation (Infineon Technologies AG)
• Inventors: Oksman, Vladimir
• Granted Patent: US 8,718,067 B2
• Time in Patent Office: Days
• US Class Current: 370/474
• CPC Class Codes: H04L 12/4633 Interconnection of networks using encapsulation techniques, e.g. tunneling
• CPC Class Codes: H04L 2212/00 Encapsulation of packets
• CPC Class Codes: H04L 47/10 Flow control; Congestion control
• CPC Class Codes: H04L 47/245 using preemption
• CPC Class Codes: H04L 7/041 using special codes as synchronising signal

Abstract

Protocols or methods are presented for encapsulating data from packets of different priorities and pre-emption techniques therefor using (N+M) byte frames for transmission in a communications system. The methods involve selectively suspending encapsulation of low-priority data packets to encapsulate a higher priority pre-empting data packet, and resuming encapsulation all or a portion of remaining data from a suspended low-priority data packet in a frame in which a pre-empting higher priority data packet is completed.

Claims

1. A method of encapsulating data from prioritized data packets in frames for transport in a communication system, the method comprising:

forming frames consisting of an integer number M sync bytes indicative of a frame boundary and a data field consisting of an integer number N byte fields, M and N being positive integers, wherein the individual frames are a fixed number N+M bytes long;

encapsulating data from data packets in data fields of one or more frames for transportation in the communication system;

selectively suspending encapsulation of data from a data packet of a first priority to encapsulate data from a pre-empting data packet of a second priority; and

resuming encapsulation of at least a portion of remaining data from a suspended data packet of the first priority in a frame in which a preempting data packet of the second priority is completed.

2. The method of claim 1, wherein both the preempting and pre-empted data packets can be short packets having a length less than N−

1 bytes.

3. The method of claim 2, wherein the preempting packet is a short packet that starts and completes in a single frame, and wherein resuming encapsulation of at least a portion of the remaining data comprises encapsulating at least a portion of the remaining data from the suspended data packet in the frame in which the preempting data packet starts and completes.

4. The method of claim 3, wherein resuming encapsulation of at least a portion of remaining data from a suspended data packet comprises providing a control byte in the data field after a final data byte of the pre-empting data packet, the control byte being indicative of an end of the data bytes of the suspended data packet in the data field of the same frame.

5. The method of claim 4, wherein resuming encapsulation of at least a portion of remaining data from a suspended data packet further comprises providing a start byte in the data field after the control byte and before the data bytes of the suspended data packet, the start byte being indicative of a start of the remaining data bytes of the suspended data packet in the data field.

6. The method of claim 3, wherein M=1 and N=64.

7. The method of claim 2, wherein resuming encapsulation of at least a portion of remaining data from a suspended data packet comprises providing a control byte in the data field after a final data byte of the preempting data packet, the control byte being indicative of an end of the data bytes of the suspended data packet in the data field.

8. The method of claim 7, wherein resuming encapsulation of at least a portion of remaining data from a suspended data packet further comprises providing a start byte in the data field after the control byte and before the data bytes of the suspended data packet, the start byte being indicative of a start of the remaining data bytes of the suspended data packet in the data field.

9. The method of claim 2, wherein M=1 and N=64.

10. The method of claim 1, wherein resuming encapsulation of at least a portion of remaining data from a suspended data packet comprises providing a control byte in the data field after a final data byte of the preempting data packet, the control byte being indicative of an end of the data bytes of the suspended data packet in the data field of the same frame.

11. The method of claim 10, wherein resuming encapsulation of at least a portion of remaining data from a suspended data packet further comprises providing a start byte in the data field after the control byte and before the data bytes of the suspended data packet, the start byte being indicative of a start of the remaining data bytes of the suspended data packet in the data field.

12. The method of claim 1, wherein M=1 and N=64.

13. The method of claim 1, wherein resuming encapsulation of at least a portion of remaining data from a suspended data packet further comprises providing the M sync bytes that indicate that the pre-empting data packet completes in the current frame.

14. A pre-emption method for prioritized encapsulation of data packets in fixed length N+M byte frames for transport in a communication system, the pre-emption method comprising:

selectively suspending encapsulation of data from a low-priority data packet to encapsulate data from a higher priority pre-empting data packet; and

resuming encapsulation of at least a portion of remaining data from a suspended low-priority data packet in a frame in which a pre-empting higher priority data packet is completed.

15. The pre-emption method of claim 14, wherein the data packets can be short packets having a length less than N−

1 bytes.

16. The pre-emption method of claim 15, wherein the higher priority pre-empting packet is a short packet that starts and completes in a single frame, and wherein resuming encapsulation of at least a portion of the remaining data comprises encapsulating at least a portion of the remaining data from the suspended low-priority data packet in the frame in which the higher priority pre-empting data packet starts and completes.

17. The pre-emption method of claim 14, wherein resuming encapsulation of at least a portion of remaining data from a suspended low-priority data packet comprises providing a control byte in the data field after a final data byte of the pre-empting higher priority data packet, the control byte being indicative of an end of the data bytes of the suspended low-priority data packet in the data field.

18. The pre-emption method of claim 17, wherein resuming encapsulation of at least a portion of remaining data from a suspended low-priority data packet further comprises providing a start byte in the data field after the control byte and before the data bytes of the suspended low-priority data packet, the start byte being indicative of a start of the remaining data bytes of the suspended low-priority data packet in the data field.

19. The pre-emption method of claim 14, wherein M=1 and N=64.

20. The pre-emption method of claim 14, wherein resuming encapsulation of at least a portion of remaining data from a suspended low-priority data packet further comprises providing the M sync bytes that indicate that the higher priority pre-empting data packet completes in the current frame.