Sending notification through a firewall over a computer network

• US 7,215,777 B2
• Filed: 01/16/2001
• Issued: 05/08/2007
• Est. Priority Date: 01/16/2001
• Status: Expired due to Fees

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Deen, Brian J., Lyndersay, Sean O., Soderberg, Joel M., Hopmann, Alex I.
• Primary Examiner(s): Zand; Kambiz
• Assistant Examiner(s): Tran; Tongoc
• Application Number:
  US09/761,374
• Publication Number:
  US 20020095600A1
• Time in Patent Office: 2,303 Days
• Field of Search: 710200-201, 710/152, 710/181, 380270-271, 709/219, 709/228, 713/152
• US Class Current: 380/270
• CPC Class Codes: H04L 63/029 Firewall traversal, e.g. tunnelling or, creating pinholes

Abstract

Methods and systems for efficiently sending notification of the occurrence of events through a firewall. A client system operating inside a firewall, attempts to receive notification of the occurrence of events from a server system operating outside the firewall. The client system attempts to receive communication from the server system using a connectionless protocol, such as UDP. If the client system receives communication using the connectionless protocol, the client system requests notification be sent using the connectionless protocol. The server system notifies the client system by sending a packet to the server system, using the connectionless protocol, when events occur. However, if the client does not receive communication using the connectionless protocol, the client requests notifications be sent using a connection-oriented protocol, such as TCP. If the client system requests notification using a connection-oriented protocol, the client system polls the server system to receive notification of the occurrence of events.

Claims

1. In a network system including a server system, a client system and a firewall wherein the server system monitors the occurrence of events, sends notification through the firewall to the client system after one of the monitored events occurs, a method for efficiently notifying the client system of the occurrence of a monitored event, so as to provide notification in a manner preserving the processing capacity of the server system and the client system, and preserving bandwidth on the network system, the method comprising:

an act of the client system sending a request to the server system, wherein the request is that the server system transmit a packet of data containing notification of the occurrence of an event to the client system using a connectionless protocol, wherein the connectionless protocol does not require a session be established between the client system and the server system in order for communication to occur between the client system and the server system;

an act of the client system attempting to receive the packet of data containing notification of the occurrence of an event from the server system, wherein the packet of data is sent using the connectionless protocol;

an act of the client system determining, based on the act of attempting to receive the packet of data from the server system, whether or not the client system can receive notifications, generated as the result of the happening of a monitored event, from the server system using a connectionless protocol,

an act of the client system requesting that server system initiated notifications be sent using the connectionless protocol, if the attempt to receive the packet of data is successful;

an act of the client system requesting that server system initiated notifications be sent using a connection-oriented protocol, if the attempt to receive the packet of data is not successful, wherein the connection-oriented protocol establishes a session between the client system and the server system in order for communication to occur between the client system and the server system;

an act of the client system detecting changes in firewall configuration including changes indicating that data packets sent via a connectionless protocol are being allowed through the firewall; and

upon determining that data packets sent via a connectionless protocol are being allowed through the firewall, an act of the client system automatically shifting to receiving data packets containing event notifications via the connectionless protocol even though a connection-oriented protocol is available.

2. The method as recited in claim 1, wherein the act of the client system requesting server system initiated notifications be sent using a connection-oriented protocol, further comprises an act of the client system attempting to establish a connection to the server system using the connection-oriented protocol.

3. The method as recited in claim 1, wherein the attempt to receive the packet of data is not successful if the packet of data is not received within a prespecified period of time.

4. The method as recited in claim 1, wherein the connection-oriented protocol is the Transmission Control Protocol.

5. The method as recited in claim 1, wherein the connectionless protocol is the User Datagram Protocol.

6. The method as recited in claim 1, wherein the act of the client system requesting that server system initiated notifications be sent using the connectionless protocol comprises an act of making an express request that notifications be sent using the connectionless protocol.

7. The method as recited in claim 1, wherein the server is configured to, by default, send notifications using a connectionless protocol absent any instruction to the contrary, wherein the act of the client system requesting that server system initiated notifications be sent using the connectionless protocol comprises an act of abstaining from making an express request thereby impliedly requesting that server system initiated notifications be sent using the connectionless protocol.

8. The method of claim 1, wherein the act of the client system sending a request to the server system, wherein the request is that the server system transmit a packet of data to the client system using a connectionless protocol comprises sending a message using a connection-oriented protocol.

9. The method of claim 1, wherein the act of the client system sending a request to the server system, wherein the request is that the server system transmit a packet of data to the client system using a connectionless protocol is performed at some time before the notification of an event might occur.

10. In a network system including a server system, a client system and a firewall wherein the server system monitors the occurrence of events, sends notification through the firewall to the client system after one of the monitored events occurs, a method for determining if notification from the server system to the client system is viable, using a connectionless protocol, so as to provide notification in a manner preserving the processing capacity of the server system and the client system, and preserving bandwidth on the network system, the method comprising:

a step for the client system to determine if communication can be received from the server system using the connectionless protocol, wherein the connectionless protocol does not require a session be established between the client system and the server system in order for communication to occur between the client system and the server system;

an act of the client system determining, based on the act of attempting to receive the packet of data from the server system, whether or not the client system can receive notifications, generated as the result of the happening of a monitored event, from the server system using a connectionless protocol,

an act of the client system requesting that server system initiated notifications be sent using the connectionless protocol, if the attempt to receive the packet of data is successful;

an act of the client system requesting that server system initiated notifications be sent using a connection-oriented protocol, if the attempt to receive the packet of data is not successful, wherein the connection-oriented protocol establishes a session between the client system and the server system in order for communication to occur between the client system and the server system;

an act of the client system detecting changes in firewall configuration including changes indicating that data packets sent via a connectionless protocol are being allowed through the firewall; and

upon determining that data packets sent via a connectionless protocol are being allowed through the firewall, an act of the client system automatically shifting to receiving data packets containing event notifications via the connectionless protocol even though a connection-oriented protocol is available.

11. The method as recited in claim 10, wherein the act of the client system requesting server system initiated notifications be sent using a connection-oriented protocol, further comprises an act of the client system attempting to establish a connection to the server system using the connection-oriented protocol.

12. The method as recited in claim 10, wherein the attempt to receive the packet of data is unsuccessful if the packet of data is not received within a prespecified period of time.

13. The method as recited in claim 10, wherein the connection-oriented protocol is the Transmission Control Protocol.

14. The method as recited in claim 10, wherein the connectionless protocol is the User Datagram Protocol.

15. The method as recited in claim 10, wherein the act of the client system requesting that server system initiated notifications be sent using the connectionless protocol comprises an act of making an express request that notifications be sent using the connectionless protocol.

16. The method as recited in claim 10, wherein the server is configured to, by default, send notifications using a connectionless protocol absent any instruction to the contrary, wherein the act of the client system requesting that server system initiated notifications be sent using the connectionless protocol comprises an act of abstaining from making an express request thereby impliedly requesting that server system initiated notifications be sent using the connectionless protocol.

17. The method as recited in claim 10, wherein the step for the client system to determine if communication can be received from the server system using the connectionless protocol comprises the following:

an act of the client system sending a request to the server system, wherein the request is that the server system transmit a packet of data to the client system using a connectionless protocol; and

an act of the client system attempting to receive a packet of data from the server system, wherein the packet of data is sent using a connectionless protocol.

18. A computer product claim for implementing, in a network system including a server system and a client system, wherein the server system monitors the occurrence of events, sends notification to the client system after one of the monitored events occurs, a method for efficiently notifying the client system, so as to provide notification in a manner preserving the processing capacity of the server system and the client system, and preserving bandwidth on the network system, the computer product comprising:

a computer-readable medium carry computer executable-instructions that, when executed at the client computer, cause the client system to perform the following;

an act of sending a request to the server system, wherein the request is that the server system transmit a packet of data containing notification of the occurrence of an event to the client system using a connectionless protocol, wherein the connectionless protocol does not require a session be established between the client system and the server system in order for communication to occur between the client system and the server system;

an act of attempting to receive the packet of data containing notification of the occurrence of an event from the server system, wherein the packet of data is sent using the connectionless protocol;

an act of the client system determining, based on the act of attempting to receive the packet of data from the server system, whether or not the client system can receive notifications, generated as the result of the happening of a monitored event, from the server system using a connectionless protocol,

an act of requesting that server system initiated notifications be sent using the connectionless protocol, if the attempt to receive the packet of data is successful;

an act of requesting that server system initiated notifications be sent using a connection-oriented protocol, if the attempt to receive the packet of data is not successful, wherein the connection-oriented protocol establishes a session between the client system and the server system in order for communication to occur between the client system and the server system;

an act of the client system detecting changes in firewall configuration including changes indicating that data packets sent via a connectionless protocol are being allowed through the firewall; and

upon determining that data packets sent via a connectionless protocol are being allowed through the firewall, an act of the client system automatically shifting to receiving data packets containing event notifications via the connectionless protocol even though a connection-oriented protocol is available.

19. The computer product as recited in claim 18, wherein the act of requesting server system initiated notifications be sent using a connection-oriented protocol, further comprises an act of attempting to establish a connection to the server system using the connection-oriented protocol.

20. The computer program product as recited in claim 18, wherein the attempt to receive the packet of data is unsuccessful if the packet of data is not received within a prespecified period of time.

21. The computer program product as recited in claim 18, wherein the connection-oriented protocol is the Transmission Control Protocol.

22. The computer program product as recited in claim 18, wherein the connectionless protocol is the User Datagram Protocol.

23. The computer program product as recited in claim 18, wherein the computer-readable medium comprises one or more physical storage media.