Method and system for proxying telephony messages

• US 7,366,792 B2
• Filed: 05/11/2004
• Issued: 04/29/2008
• Est. Priority Date: 05/25/2000
• Status: Expired due to Fees

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Kleyman, Ilya A., Kumar, Deepak, Chitturi, Ajay P., Davis, Arlie L.
• Primary Examiner(s): Caldwell; Andrew
• Assistant Examiner(s): BLAIR, DOUGLAS B
• Application Number:
  US10/842,887
• Publication Number:
  US 20040210774A1
• Time in Patent Office: 1,449 Days
• Field of Search: 709/203, 709/230, 709/245, 370251-252
• US Class Current: 709/245
• CPC Class Codes: H04L 65/1045 Proxies, e.g. for session initiation protocol [SIP]
• CPC Class Codes: H04M 3/42314 in private branch exchanges
• CPC Class Codes: H04M 7/0075 Details of addressing, directories or routing tables

Abstract

A proxy computer of a network can receive incoming telephony messages from one or more computers outside of the network and proxy them to computers within the network. Similarly, the proxy computer can receive outgoing telephony messages from within the network and proxy them to computers outside of the network. To set up inbound calls, a proxy program on the proxy computer looks for the presence of an alias in the call signaling messages, references a data structure to determine which computer on the network is associated with the alias, and proxies the call signaling and control messages between the callee computer and the calling computer based on the association, thereby creating a logical connection between the calling computer and the callee computer.

Claims

1. A method of proxying telephony messages on a proxy computer of a network, the method comprising the following steps:

registering an alias corresponding to a callee computer with a directory service, the directory service associates an internet protocol (IP) address of the proxy computer with the alias;

utilizing the alias of the callee computer to request the IP address, a calling computer initiates the request to the callee computer using the alias;

submitting the request to the directory service, the directory service matches the alias in a directory and returns the IP address that is listed for the alias, which is the public network address of the proxy computer;

receiving a first call control message from a calling computer of a public network, the first call control message comprising the public network address of the proxy computer and a first set of port assignments assigned by the calling computer for media communication between the proxy computer and the calling computer on behalf of the callee computer;

generating a second call control message, the second call control message comprising a private network address of the callee computer and a second set of port assignments assigned by the proxy computer for media communication between the proxy computer and the callee computer on behalf of the calling computer; and

sending the second call control message to the callee computer, the proxy computer sends the second call control message to the callee computer on behalf of the calling computer.

2. The method of claim 1, wherein the first and second call control messages are open logical channel messages for opening logical channels between the calling computer and the proxy computer and between the callee computer and the proxy computer, respectively.

3. The method of claim 2, wherein the open logical channel messages are structured in accordance with the H.245 protocol.

4. A computer -readable medium having stored thereon computer-executable instructions for performing the steps of claim 3.

5. A computer -readable medium having stored thereon computer-executable instructions for performing the steps of claim 2.

6. A computer -readable medium having stored thereon computer-executable instructions for performing the steps of claim 1.

7. The method of claim 1, wherein the first set of port assignments includes a port for audio transmissions and another port for video transmissions between the proxy computer and the calling computer on the behalf of the callee computer.

8. The method of claim 1, wherein the second set of port assignments includes a port for audio transmissions and another port for video transmissions between the proxy computer and the callee computer on the behalf of the calling computer.

9. The method of claim 1, wherein the calling computer exchanges data with the private network computer via the proxy computer using the first set of ports assigned by the calling computer, and the proxy computer forwards the data to the private network computer using the second set of ports assigned by the proxy computer.