System and method for managing out of order packets in a network environment

• US 8,792,495 B1
• Filed: 12/19/2009
• Issued: 07/29/2014
• Est. Priority Date: 12/19/2009
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Dixon, Walter, Kalyanakrishnan, Mahesh C., Yeh, Showen, Tavres, Humberto M.
• Primary Examiner(s): Lai, Andrew
• Assistant Examiner(s): ANDREWS, LEON T
• Application Number:
  US12/642,790
• Time in Patent Office: 1,683 Days
• Field of Search: None
• US Class Current: 370/394
• CPC Class Codes: H04L 45/38 Flow based routing
• CPC Class Codes: H04L 47/34 ensuring sequence integrity, e.g. using sequence numbers
• CPC Class Codes: H04L 47/624 Altering the ordering of packets in an individual queue

Abstract

A method is provided in one example and includes receiving a request packet associated with a flow; designating an out of order sequence number range associated with the flow; creating an entry that designates the out of order sequence number range; receiving a subsequent packet that includes a particular sequence number range; referencing the out of order sequence number range; resolving a portion of the entry corresponding to the particular sequence number range for the subsequent packet; and forwarding the subsequent packet. In other embodiments, the request packet includes a content length field indicating the out of order sequence number range associated with the flow. Creating the entry can include creating a segment within a queue for the out of order sequence number range, which reflects expected sequence numbers for packets associated with the flow.

Claims

1. A method, comprising:

receiving at a network element a request packet associated with a flow;

creating at the network element an entry that designates an out of order sequence number range associated with the flow;

receiving at the network element a subsequent packet that includes a particular sequence number range;

resolving at the network element a portion of the entry corresponding to the particular sequence number range for the subsequent packet by removing numbers comprising the particular sequence number range from the out of order sequence number range; and

forwarding from the network element the subsequent packet without awaiting receipt of any other packets associated with the flow;

wherein the request packet includes a content length field indicating the out of order sequence number range associated with the flow.

2. The method of claim 1, further comprising:

receiving an additional packet associated with the flow;

referencing a queue that includes a plurality of entries associated with the out of order sequence number range; and

identifying no match associated with the additional packet such that the additional packet is classified as being a retransmission.

3. The method of claim 1, wherein creating the entry includes creating a segment within a queue for the out of order sequence number range, which reflects expected sequence numbers for packets associated with the flow.

4. The method of claim 1, further comprising:

accounting for a number of transmission control protocol (TCP) bytes passing through a network element; and

accounting for packets received at the network element.

5. The method of claim 1, further comprising:

updating the out of order sequence number range after resolving the portion of the entry associated with the subsequent packet.

6. The method of claim 1, further comprising:

billing a first set of packets associated with the flow in response to forwarding the first set of packets, wherein the request packet is associated with a data type in which out of order processing for packets within the flow is permissible.

7. One or more non-transitory tangible media that includes code for execution and when executed by a processor causes performance of operations comprising:

receiving a request packet associated with a flow;

creating an entry that designates an out of order sequence number range associated with the flow;

receiving a subsequent packet that includes a particular sequence number range;

resolving a portion of the entry corresponding to the particular sequence number range for the subsequent packet by removing numbers comprising the particular sequence number range from the out of order sequence number range; and

forwarding the subsequent packet without awaiting receipt of any other packets associated with the flow;

wherein the request packet includes a content length field indicating the out of order sequence number range associated with the flow.

8. The one or more non-transitory tangible media of claim 7, the operations further comprising:

receiving an additional packet associated with the flow;

referencing a queue that includes a plurality of entries associated with the out of order sequence number range; and

identifying no match associated with the additional packet such that the additional packet is classified as being a retransmission.

9. The one or more non-transitory tangible media of claim 7, wherein creating the entry includes creating a segment within a queue for the out of order sequence number range, which reflects expected sequence numbers for packets associated with the flow.

10. The one or more non-transitory tangible media of claim 7, the operations further comprising:

accounting for a number of transmission control protocol (TCP) bytes passing through a network element; and

accounting for packets received at the network element.

11. The one or more non-transitory tangible media of claim 7, the operations further comprising:

updating the out of order sequence number range after resolving the portion of the entry associated with the subsequent packet.

12. An apparatus, comprising:

a memory element configured to store data,

a processor to execute instructions associated with the data, and

a tracking module configured to;

receive a request packet associated with a flow;

create an entry that designates an out of order sequence number range associated with the flow;

receive a subsequent packet that includes a particular sequence number range;

resolve a portion of the entry corresponding to the particular sequence number range for the subsequent packet by removing numbers comprising the particular sequence number range from the out of order sequence number range; and

forward the subsequent packet without awaiting receipt of any other packets associated with the flow;

wherein the request packet includes a content length field indicating the out of order sequence number range associated with the flow.

13. The apparatus of claim 12, further comprising:

a policy control enforcement function (PCEF) module configured to render policy decisions associated with the flow.

14. The apparatus of claim 12, further comprising:

a queue that includes one or more entries that can be updated as additional packets are received and that are associated with expected sequence numbers associated with the flow.

15. The apparatus of claim 12, further comprising:

a hypertext transfer protocol (HTTP) protocol handler configured to parse incoming headers for incoming packets and to determine the out of order sequence number range associated with the flow.

16. The apparatus of claim 12, further comprising:

a session services module configured to compare incoming packets to the out of order sequence number range and to execute decisions concerning forwarding or queuing certain incoming packets.

17. The apparatus of claim 12, wherein the tracking module is further configured to:

update the out of order sequence number range after resolving the portion of the entry associated with the subsequent packet.