In sequence packet delivery without retransmission

• US 20040100963A1
• Filed: 11/25/2002
• Published: 05/27/2004
• Est. Priority Date: 11/25/2002
• Status: Active Grant

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Guo, Xingang
• Granted Patent: US 7,796,602 B2
• Time in Patent Office: Days
• US Class Current: 370/394
• CPC Class Codes: H04L 47/10 Flow control; Congestion control
• CPC Class Codes: H04L 47/27 Evaluation or update of window size, e.g. using information derived from acknowledged [ACK] packets
• CPC Class Codes: H04L 47/32 by discarding or delaying data units, e.g. packets or frames
• CPC Class Codes: H04L 47/34 ensuring sequence integrity, e.g. using sequence numbers
• CPC Class Codes: H04W 28/10 Flow control between communication endpoints
• CPC Class Codes: H04W 28/14 using intermediate storage
• CPC Class Codes: H04W 8/04 Registration at HLR or HSS [Home Subscriber Server]

Abstract

A method of re-ordering packets receives packets having packet sequence numbers. The method then determines if a packet is an out of window packet and buffers out-of-window packets having a sequence number more than a first number. The method delivers a packet when the packet sequence number matches a first number. It delivers all buffered packets when a timeout occurs. A communication system having at least one network device that performs this method is also disclosed.

Claims

1. A method of re-ordering packets, the method comprising:

receiving packets having packet sequence numbers;

determining if a packet is an out-of-window packet; and

buffering out-of-window packets having a sequence number more than a first number.

2. The method of claim 1, the method further comprising buffering packets with packet sequence numbers within a window of packet sequence numbers.

3. The method of claim 1, the method further comprising:

delivering those packets having a packet sequence number equal to the first number; and

advancing the first number by one.

4. The method of claim 3, wherein the method further comprising examining sequence numbers of packets that are buffered to determine if their packet sequence numbers are equal to a first number.

5. The method of claim 1, the method further comprising discarding out-of-window packets having a sequence number less than the expected sequence number.

6. The method of claim 1, the method further comprising:

delivering packets that are buffered upon expiration of a timer;

advancing the expected sequence number to a second number; and

resetting the timer.

7. The method of claim 6, wherein the second number is equal to a sequence number of a packet that was delivered having the highest sequence number plus one.

8. The method of claim 1, the method further comprising:

determining if a buffer is full; and

if the buffer is full delivering a packet with the lower packet sequence number between packets that are buffered and a current packet.

9. An article comprising a machine-accessible medium having associated instructions that, when executed, cause the machine to:

receive packets having packet sequence numbers;

determine if a packet is an out of window packet; and

buffer out-of-window packets having a sequence number more than a first number.

10. The article of claim 9 further comprising instructions that, when executed, further cause the machine to buffer packets with packet sequence numbers within a window of packet sequence numbers.

11. The article of claim 9, wherein the instructions, when executed, further cause the machine to:

deliver those packets having a packet sequence number equal to the first number; and

advance the first number by one.

12. The article of claim 9, wherein the instructions, when executed, further cause the machine to examine sequence numbers of packets that are buffered to determine if their packet sequence numbers are equal to a first number.

13. The article of claim 9, wherein the instructions, when executed, further cause the machine to discard out-of-window packets having a sequence number less than the expected sequence number.

14. The article of claim 9, wherein the instructions, when executed, further cause the machine to:

deliver packets that are buffered upon expiration of a timer;

advance the expected sequence number to a second number; and

reset the timer.

15. The article of claim 9, wherein the instructions, when executed, further causes the machine to:

determine if a buffer is full; and

if the buffer is full, deliver a packet with the lower packet sequence number between packets that are buffered and a current packet.

16. A communication system, comprising:

a transmitting station to transmit packets;

a receiving station in communication with the transmitting station to receive packets and to run an application; and

a network device to re-order packets prior to delivery to the application such that out-of-window packets are buffered if the packets have a sequence number more than a first number.

17. The communication system of claim 16, the system further comprising a tunnel between the transmitting and receiving station.

18. The communication system of claim 17, the tunnel further comprising a general packet radio system tunneling protocol tunnel.

19. The communication system of claim 17, wherein the network device resides at the receiving station.

20. The communication system of claim 17, wherein the network device resides at an intermediate point between the transmitting station and the receiving station.