Flow control between performance enhancing proxies over variable bandwidth split links

• US 20030123394A1
• Filed: 11/13/2002
• Published: 07/03/2003
• Est. Priority Date: 11/13/2001
• Status: Abandoned Application

• Current Assignee: Advantech Satellite Networks Inc.
• Original Assignee: EMS Technologies, Inc. (Honeywell International Inc.)
• Inventors: Mohsen, Abdul-Kader, Neale, Jason, Pether, Andrew M., Begin, Guy
• Application Number:
  US10/292,901
• Publication Number:
  US 20030123394A1
• Time in Patent Office: Days
• US Class Current: 370/235
• CPC Class Codes: H04B 7/18582 Arrangements for data linking, i.e. for data framing, for error recovery, for multiple access
• CPC Class Codes: H04L 1/18 Automatic repetition systems, e.g. Van Duuren systems
• CPC Class Codes: H04L 1/1832 Details of sliding window management
• CPC Class Codes: H04L 1/1848 Time-out mechanisms
• CPC Class Codes: H04L 12/2856 Access arrangements, e.g. Internet access asynchronous transfer mode networks H04L12/5601; broadband local area networks H04L12/2801; optical access or distribution networks H04Q11/0067; access to open networks H04L12/5691; digital subscriber line end-user equipment and bit-level processing of data on a PSTN-based network H04M11/00; home network gateways H04L12/2834; wireless access networks H04W
• CPC Class Codes: H04L 47/10 Flow control; Congestion control
• CPC Class Codes: H04L 47/193 at the transport layer, e.g. TCP related
• 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 47/323 Discarding or blocking control packets, e.g. ACK packets
• CPC Class Codes: H04L 47/36 by determining packet size, e.g. maximum transfer unit [MTU]
• CPC Class Codes: H04L 67/04 specially adapted for terminals or networks with limited capabilities; specially adapted for terminal portability
• CPC Class Codes: H04L 69/16 Implementation or adaptation of Internet protocol [IP], of transmission control protocol [TCP] or of user datagram protocol [UDP]
• CPC Class Codes: H04L 69/161 Implementation details of TCP/IP or UDP/IP stack architecture; Specification of modified or new header fields
• CPC Class Codes: H04L 69/163 In-band adaptation of TCP data exchange; In-band control procedures
• CPC Class Codes: H04L 69/165 Combined use of TCP and UDP protocols; selection criteria therefor
• CPC Class Codes: H04L 69/166 IP fragmentation; TCP segmentation
• CPC Class Codes: H04L 69/326 in the transport layer [OSI layer 4] H04L69/16 takes precedence
• CPC Class Codes: H04L 69/329 in the application layer [OSI layer 7]
• CPC Class Codes: H04L 9/40 Network security protocols
• CPC Class Codes: H04W 28/0273 : adapting protocols for flow control or congestion control to wireless environment, e.g. adapting transmission control protocol [TCP] wireless network protocols or protocol adaptations to wireless operation, e.g. wireless application protocol H04W80/00
• CPC Class Codes: H04W 72/0453 : Resources in frequency domain, e.g. a carrier in FDMA
• CPC Class Codes: H04W 8/04 : Registration at HLR or HSS [Home Subscriber Server]
• CPC Class Codes: H04W 80/06 : Transport layer protocols, e.g. TCP [Transport Control Protocol] over wireless transmission control protocol/Internet protocol [TCP/IP] or user datagram protocol [UDP] H04L69/16
• CPC Class Codes: H04W 84/06 : Airborne or Satellite Networks space-based or airborne stations H04B7/185

Abstract

The invention provides a method and system for dealing with the flow of data between one Performance Enhancement Proxy and another in the context of split links for TCP over satellite performance improvement. The environment according to the invention may include one or more intermediate nodes experiencing variable latency and bandwidth allocations. The method and system manage the data flow to ensure bandwidth fairness between competing TCP/IP connections, prevention of PEP receiver buffer overflow and near 100% usage of the available satellite bandwidth without the need for conventional TCP/IP ACK driven probing algorithms. The near 100% usage of capacity being achieved, in part, through PEP to intermediate node message exchange.

Claims

1. In a distributed connection splitting system, which comprises at least two intermediate nodes, a method for managing data flow between the intermediate nodes and through an intermediate device, comprising the steps of:

obtaining status data of the intermediate device; and

managing the flow of data between the intermediate nodes and the intermediate device by determining the status of an intermediate device queue.

2. The method of claim 1, wherein the amount of at least one of data and packet space in the intermediate device is used to determine the quantity of at least one of data and packets which should be sent to the intermediate device.

3. The method of claim 1, wherein the intermediate nodes send sufficient data to at-least partially fill the intermediate device queue to a pre-defined level, and after a pre-determined delay to allow data to be transmitted, checks the status of the intermediate device and then re-fills the intermediate device queue to a previous level.

4. The method of claim 1, wherein the intermediate nodes send regular SNAP get messages to an intermediate device MIB or the intermediate device sends SNAP traps when a queue reaches a pre-detemined level to indicate the current queue status.

5. The method of claim 1, wherein the flow of data from the intermediate nodes to the intermediate device is more accurate by the intermediate nodes having knowledge of current and future bandwidth information from the intermediate device.

6. The method of claim 5, wherein the intermediate nodes and the intermediate device are co-located in the same device with some form of direct linkage between the allocated bandwidth/queue and the intermediate nodes.

7. A method of fairly distributing bandwidth among connections in a communications system, comprising the step of sharing of transmission storage amongst a number N connections.

8. The method according to claim 7, wherein the step of sharing further includes the steps of:

calculating an amount of capacity given to a connection before allowance for any applicable intermediate node to Intermediate device flow is X/N, where X is the maximum bandwidth-delay product of a communication and N is the number of connections;

determining if a sum of all the actual capacity usage by each individual connection N is less than X, wherein the available capacity is shared by any connections wishing to exceed an allocation; and

determining, if new connections arrive, whether they are guaranteed (X/N) capacity even if the result is a temporarily over-supply of capacity to a link resulting in buffering at an output queue of the intermediate node.

9. A method for managing the flow of data from an intermediate node to an intermediate device so that the transmission of data depends upon:

sufficient transmission buffer space in the sending intermediate node;

sufficient space in the receiver window of the receiving intermediate node; and

sufficient capacity/buffer space at one of the intermediate devices.

10. The method of claim 9, wherein the failure of a test causes data to be stored in an applicable input or output queue within the intermediate node thereby creating natural back pressure to a TCP sender in the regular window updates sent from the intermediate node to the TCP sender.