Method and apparatus for controlling network traffic

• US 20020035642A1
• Filed: 07/31/2001
• Published: 03/21/2002
• Est. Priority Date: 09/18/2000
• Status: Active Grant

• Current Assignee: Unwired Planet LLC (JP Morgan Chase & Co)
• Original Assignee: Openwave Systems Incorporated (JP Morgan Chase & Co)
• Inventors: Luna, Michael E.S., Clarke, James, Wood, Nicholas
• Granted Patent: US 7,237,034 B2
• Time in Patent Office: Days
• US Class Current: 709/244
• CPC Class Codes: H04L 47/10 Flow control; Congestion control
• CPC Class Codes: H04L 47/12 Avoiding congestion; Recovering from congestion
• CPC Class Codes: H04L 47/266 Stopping or restarting the source, e.g. X-on or X-off
• CPC Class Codes: H04L 47/28 in relation to timing considerations
• CPC Class Codes: Y02D 30/50 in wire-line communication networks, e.g. low power modes or reduced link rate

Abstract

An intermediary node on a data communications network implements a flow control algorithm to control network congestion. The intermediary node receives messages destined for servers or other upstream nodes from clients or other downstream nodes and determines whether to forward the messages based on the flow control algorithm, which may be adaptive. The algorithm may consider explicit back-off messages received from upstream nodes, failure of upstream nodes to respond to messages forwarded by the intermediary node, and/or other criteria. When a back-off condition applies, the intermediary node refrains from forwarding messages it receives and sends back-off messages to nodes initiating the messages. Back-off messages may include a back-of time period and/or other back-off criteria.

Claims

1. A method comprising:

using an intermediary node on a network to forward messages on behalf of a plurality of other nodes on the network; and

determining, in the intermediary node, when a message received by the intermediary node and destined for one of the other nodes should not be forwarded, based on detected congestion on the network.

2. A method as recited in claim 1, wherein said determining comprises executing a message flow control algorithm in the intermediary node.

3. A method as recited in claim 1, further comprising using the intermediary node to detect congestion on the network.

4. A method as recited in claim 3, wherein using the intermediary node to detect congestion on the network comprises detecting congestion on the network based on a back-off message received by the intermediary node from an upstream node on the network.

5. A method as recited in claim 4, wherein the back-off message specifies one or more back-off criteria.

6. A method as recited in claim 5, wherein the back-off criteria comprise metadata indicating applicability of the back-off message.

7. A method as recited in claim 3, wherein using the intermediary node to detect congestion on the network comprises detecting congestion on the network based on a failure by an upstream node on the network to respond to a request forwarded by the intermediary node.

8. A method as recited in claim 1, further comprising using the intermediary node to provide a message indicating congestion on the network to a downstream node on the network, when congestion on the network is detected.

9. A method as recited in claim 8, wherein the message is sent in response to the intermediary node receiving a request from the downstream device destined for an upstream node on the network.

10. A method as recited in claim 8, wherein the message specifies a back-off criterion for use by the downstream node.

11. A method as recited in claim 10, further comprising computing the back-off criterion in the intermediary node.

12. A method as recited in claim 11, wherein the back-off criterion comprises a back-off time period.

13. A method as recited in claim 1, wherein said determining comprises using a back-off strategy to determine when a request received by the intermediary node should not be forwarded, and wherein the method further comprises adapting the back-off strategy dynamically based on operation of the network.

15. A method as recited in claim 14, wherein the landline network is the Internet.

16. A method as recited in claim 14, wherein said determining comprises executing a message flow control algorithm in the intermediary network node.

17. A method as recited in claim 14, wherein said using the intermediary network node to detect congestion on the network comprises receiving a back-off message from an upstream node on the network.

18. A method as recited in claim 14, wherein said using the intermediary network node to detect congestion on the network comprises detecting a failure by one of the servers to respond to a request forwarded by the intermediary network node.

19. A method as recited in claim 14, further comprising using the intermediary network node to send a back-off message to the client upon determining that the request should not be forwarded.

20. A method as recited in claim 19, wherein the back-off message specifies a back-off criterion.

21. A method as recited in claim 20, further comprising computing the back-off criterion in the intermediary node.

22. A method as recited in claim 20, wherein the back-off criterion comprises a back-off time period.

23. A method as recited in claim 14, wherein said determining comprises using a back-off strategy to determine when a request received by the intermediary network node should not be forwarded, and wherein the method further comprises adapting the back-off strategy dynamically based on operation of the network.

14. A method of operating an intermediary network node, the method comprising:

using the intermediary network node to proxy requests and responses to requests between a plurality of clients and a plurality of servers, wherein at least one of the clients is a mobile client operating on a wireless network and at least one of the servers operates on a landline network, the intermediary network node coupled between the wireless network and the landline network;

using the intermediary network node to convert messages between a wireless protocol used by the wireless network and a second protocol used by the landline network;

using the intermediary network node to detect network congestion on at least the landline network; and

determining, in the intermediary network node, when a request received by the intermediary network node from one of the clients destined for one of the servers should not be forwarded by the intermediary network node, based on network congestion detected by the intermediary network node.

24. A processing system for use as an intermediary node on a network, the processing system comprising:

means for forwarding messages on behalf of a plurality of other nodes on the network;

means for detecting congestion on the network; and

means for determining when a message received by the intermediary node and destined for one of the other nodes should not be forwarded, based on congestion on the network detected by the intermediary node.

25. A machine-readable program storage medium storing computer program code, the code for execution in an intermediary node on a network to cause the intermediary node to perform a process comprising:

communicating messages between a plurality of clients on the network and a plurality of servers on the network;

detecting congestion on the network, and

determining when a request received by the intermediary node from a client on the network destined for a server on the network should not be forwarded by the intermediary node, based on congestion of the network.

26. A processing system for use as an intermediary node on a network, the processing system comprising:

a processor;

a data communication device coupled to the processor to communicate data between the processing system and a plurality of other nodes on the network; and

a storage facility coupled to the processor and storing instructions, for execution by the processor, which configure the processing system to execute a process to proxy requests and responses on behalf of the plurality of other nodes on the network, the process including;

forwarding requests from a plurality of clients on the network to a plurality of servers on the network;

forwarding responses received from the servers to the clients;

using the intermediary node to detect congestion on the network, and

determining, in the intermediary node, when a request received by the intermediary node from a client on the network destined for a server on the network should not be forwarded by the intermediary node, based on congestion of the network detected by the intermediary node.