Flow control system architecture

• US 7,656,799 B2
• Filed: 07/28/2004
• Issued: 02/02/2010
• Est. Priority Date: 07/29/2003
• Status: Active Grant

• Current Assignee: Citrix Systems, Inc. (Cloud Software Group)
• Original Assignee: Citrix Systems, Inc. (Cloud Software Group)
• Inventors: Samuels, Allen R., Sutter, Paul G.
• Primary Examiner(s): Sheikh; Ayaz R
• Assistant Examiner(s): Weidner; Timothy J
• Application Number:
  US10/901,952
• Publication Number:
  US 20050063307A1
• Time in Patent Office: 2,015 Days
• Field of Search: 370/236
• US Class Current: 370/231
• CPC Class Codes: H04L 41/12 Discovery or management of network topologies
• CPC Class Codes: H04L 43/0864 Round trip delays
• CPC Class Codes: H04L 67/2876 Pairs of inter-processing entities at each side of the network, e.g. split proxies
• CPC Class Codes: H04L 67/56 Provisioning of proxy services store-and-forward switching systems in data switching networks H04L12/54
• 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 69/166 IP fragmentation; TCP segmentation

Abstract

One or more flow control modules, implemented on various types of network topologies, provide a number of functionalities for controlling the flow of IP packets (such as TCP/IP packets) over a network connection. The flow control modules may be implemented within a sender and/or receiver or may be deployed into a network as a separate device without requiring significant additional resources.

Claims

1. A method for more efficiently utilizing network bandwidth for a plurality of sessions between a client and a server traversing a sender-side flow control module and a receiver-side flow control module, the method comprising the steps of:

(a) identifying, by a receiver flow control module, a network bandwidth between the receiver flow control module and a sender flow control module;

(b) receiving, by the sender flow control module from the receiver flow control module, responsive to a request by the sender flow control module a first transmission rate limit for a first session between a client and a server traversing the receiver flow control module and the sender flow control module, the receiver flow control module in communication with the client and intermediary to the client and the sender flow control module and the sender flow control module in communication with the server and intermediary to the server and the receiver flow control module;

(c) transmitting, by the sender flow control module, to the receiver flow control module data packets from the server to the client via the first session at a transmission rate limited by the first transmission rate limit;

(d) receiving, by the sender flow control module from the receiver flow control module, a second transmission rate limit for a second session to the server via the receiver flow control module and the sender flow control module;

(e) allocating, by the receiver flow control module, the network bandwidth between the first session and the second session based on the first transmission rate limit and the second transmission rate limit and

(f) transmitting, by the sender flow control module, to the receiver flow control module data packets from the server via the second session at a transmission rate in accordance with the allocated network bandwidth of the second session.

2. The method of claim 1 wherein step (e) further comprises modifying one of the first transmission rate limit or the second transmission rate limit.

3. The method of claim 2 further comprising transmitting, by the receiver flow control module to the sender flow control module, information about one of the modified first transmission rate limit or the modified second transmission rate limit.

4. The method of claim 1 further comprising buffering, by the sender flow control module, data packets for the first session transmitted by the server at a rate overrunning the first transmission rate limit.

5. The method of claim 4 further comprising buffering, by the sender flow control module, data packets for the second session transmitted by the server at a rate overrunning the second transmission rate limit.

6. The method of claim 1 wherein the data packets are one of internet protocol (IP) data packets or transmission control protocol (TCP) data packets.

7. A method for more efficiently utilizing a bandwidth in a network for a plurality of sessions between a plurality of clients and a server traversing a sender-side flow control module, the method comprising the steps of:

(a) identifying, by a second flow control module intermediary to a client and a plurality of flow control modules, a network bandwidth between the second flow control module and the plurality of flow control modules;

(b) receiving, by a first flow control module of the plurality of flow control modules from the second flow control module, a first transmission rate limit for a first session traversing the first flow control module and the second flow control module;

(c) receiving, by a third flow control module of the plurality of flow control modules from the second flow control module, a second transmission rate limit for a second session traversing the third flow control module and the second flow control module;

(d) allocating, by the second flow control module, based on the first transmission rate limit and the second transmission rate limit the network bandwidth between the second flow control module and the first flow control module and between the second flow control module and the third flow control module;

(e) transmitting, by the second flow control module, a modified first transmission rate limit to the first flow control module in accordance with the allocated network bandwidth between the first flow control module and the second flow control module and a modified second transmission rate limit to the third flow control module in accordance with the allocated network bandwidth between the third flow control module and the second flow control module; and

(f) transmitting, by the first flow control module, data packets to the second flow control module at a rate in accordance with the modified first transmission rate limit; and

(e) transmitting, by the third flow control module, data packets to the second flow control module at a rate in accordance with the modified second transmission rate limit.

8. The method of claim 7 wherein step (d) further comprises modifying one of the first transmission rate limit or the second transmission rate limit.

9. The method of claim 7 further comprising buffering data packets for the first data transfer session transmitted by the server at a rate overrunning the first transmission rate limit.

10. The method of claim 7 further comprising buffering data packets for the second data transfer session transmitted by the server at a rate overrunning the second transmission rate limit.

11. The method of claim 7 wherein the data packet is one of an internet protocol (IP) data packet or a transmission control protocol (TCP) data packet.

12. A method for controlling the flow of data packets between a server and a plurality of flow control modules, the data packets traversing a server-side flow control module, the method comprising the steps of:

(a) identifying, by a first flow control module of a plurality of flow control modules, a first network bandwidth between a server-side flow control module and the first flow control module and identifying, by a second flow control module of the plurality of flow control modules a second network bandwidth between the server-side flow control module and the second flow control module;

(b) receiving, by the server-side flow control module from a first flow control module of the plurality of flow control modules, a first transmission rate limit for a first session traversing the first flow control module and the server-side flow control module;

(c) receiving, by the server-side flow control module from a second flow control module of the plurality of flow control modules, a second transmission rate limit for a second session traversing the second flow control module and the server-side flow control module;

(d) allocating, by the first flow control module, based on the first transmission rate limit the network bandwidth between the first flow control module and the server-side flow control module;

(e) allocating, by the second flow control module, based on the second transmission rate limit the network bandwidth between the second flow control module and the server-side flow control module;

(f) buffering, by the server-side flow control module, data packets for the first data transfer session transmitted by the server at a rate overrunning the first transmission rate limit; and

(g) buffering, by the server-side flow control module, data packets for the second data transfer session transmitted by the server at a rate overrunning the second transmission rate limit.

13. The method of claim 12 wherein step (d) further comprises modifying one of the first transmission rate limit or the second transmission rate limit.

14. The method of claim 13 further comprising transmitting, by the server-side flow control module, a modified first transmission rate limit to the first flow control module and a modified second transmission rate limit to the second flow control module in accordance with the allocated network bandwidth.

15. The method of claim 12 further comprising transmitting, by the server-side flow control module, data packets from the server to the first flow control module at a rate identified by the modified first transmission rate limit and transmitting data packets from the server to the second flow control module at a rate identified by the modified second transmission rate limit.

16. The method of claim 12 wherein the data packets are one of internet protocol (IP) data packets or transmission control protocol (TCP) data packets.

17. A system for more efficiently utilizing a bandwidth in a network for a plurality of sessions between a plurality of clients and a server traversing a sender-side flow control module, the method comprising the steps of:

a second flow control module intermediary to a client and one or more flow control modules allocating a network bandwidth between the second flow control module and the one or more flow control modules;

a first flow control module of the one or more flow control modules transmitting to the second flow control module a first transmission rate limit for a first session traversing the first flow control module and the second flow control module;

a third flow control module of the one or more flow control modules transmitting to the second flow control module a second transmission rate limit for a second session traversing the third flow control module and the second flow control module;

wherein the second flow control module allocates, based on the first transmission rate limit, the network bandwidth between the second flow control module and the first flow control module and transmits a modified first transmission rate limit to the first flow control module in accordance with the allocated bandwidth between the second flow control module and the first flow control module and

wherein the flow control module allocates, based on the second transmission rate limit the network bandwidth between the second flow control module and the third flow control module and transmits a modified second transmission rate limit to the third flow control module in accordance with the allocated bandwidth between the second flow control module and the third flow control module; and

wherein the first flow control module transmits data packets to the second flow control module at a rate of the modified first transmission rate limit and third flow control module transmits data packets to the second flow control module at a rate of the modified second transmission rate limit.

18. The system of claim 17 wherein the second flow control module modifies one of the first transmission rate limit or the second transmission rate limit.

19. The system of claim 17 wherein the second flow control module comprises a buffer for buffering data packets of the first data transfer session transmitted by the server at a rate overrunning the first transmission rate limit.

20. The system of claim 19 wherein the buffer at the second flow control module buffers data packets for the second data transfer session transmitted by the server at a rate overrunning the second transmission rate limit.

21. The system of claim 17 wherein the data packets are one of internet protocol (IP) data packets or transmission control protocol (TCP) data packets.