Audio-video telephony with firewalls and network address translation
First Claim
1. A communications system for making a multimedia call, comprising:
- a first multimedia terminal configured to communicate using H.323;
a second multimedia terminal configured to communicate using H.323;
a first communication unit, associated with the first multimedia terminal, configured to establish a multimedia call over a shared IP network between said first multimedia terminal and the second multimedia terminal using H.323, said communication unit including a first firewall through which the multimedia call passes, whereinthe first firewall is configured to restrict certain types of communication between the first terminal and the shared IP network,each of the first multimedia terminal and the second multimedia terminal has a number of logical communication ports for transmitting or receiving the multimedia call, including at least one dynamically assigned port; and
a transmitter, associated with the first multimedia terminal is configured to send a request to the second multimedia terminal to open up one or more dynamic ports in the second multimedia terminal;
a proxy server disposed between the first multimedia terminal and the second multimedia terminal that is configured to act as a proxy for the first multimedia terminal and the second multimedia terminal during the multimedia call, whereinthe proxy server has logical communication ports for communication with the first multimedia terminal, including one or more pre-assigned ports for communication with the first multimedia terminal;
the first firewall is configured not to restrict communication between the first multimedia terminal and the one or more pre-assigned ports of the proxy server for communication with the first multimedia terminal, andthe proxy server is configured to receive the request to open up said one or more dynamic ports in the second multimedia terminal via one of the proxy server'"'"'s pre-assigned ports and to modify the request to change a source of the request from a network address of the first multimedia terminal and the at least one dynamically assigned port of the first multimedia terminal to a network address of the proxy server and a pre-assigned port of the proxy server for communication with the second multimedia terminal.
3 Assignments
0 Petitions
Accused Products
Abstract
The present invention relates to a communications system (1) for making multimedia calls. The system comprises two multimedia terminals (10,12) and communication means for making a multimedia call over a shared communications network (20), including a firewall (26) through which the multimedia call must pass, and which restricts certain types of communication. Each terminal (10,12) has a number of logical communication ports for the multimedia call, including at least one dynamically assigned port. In the course of setting up the multimedia call, at least one of the terminals (10,12) is adapted to send a request to the other of the terminals to open up one or more of the dynamic ports in the other terminal. The system includes a proxy server (40) between the terminals (10,12) that acts for each terminal as a proxy for the other terminal during the course of the call. The proxy server (40) has logical communication ports for communication with the terminals including one or more pre-assigned ports. The firewall (26) is configured not to restrict communication between one or both terminals (10,12) and the pre-assigned port(s) of the proxy server (40). The proxy server (40) is configured to receive and forward the request(s) to open up said dynamic port(s) via one of its pre-assigned ports.
72 Citations
21 Claims
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1. A communications system for making a multimedia call, comprising:
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a first multimedia terminal configured to communicate using H.323; a second multimedia terminal configured to communicate using H.323; a first communication unit, associated with the first multimedia terminal, configured to establish a multimedia call over a shared IP network between said first multimedia terminal and the second multimedia terminal using H.323, said communication unit including a first firewall through which the multimedia call passes, wherein the first firewall is configured to restrict certain types of communication between the first terminal and the shared IP network, each of the first multimedia terminal and the second multimedia terminal has a number of logical communication ports for transmitting or receiving the multimedia call, including at least one dynamically assigned port; and a transmitter, associated with the first multimedia terminal is configured to send a request to the second multimedia terminal to open up one or more dynamic ports in the second multimedia terminal; a proxy server disposed between the first multimedia terminal and the second multimedia terminal that is configured to act as a proxy for the first multimedia terminal and the second multimedia terminal during the multimedia call, wherein the proxy server has logical communication ports for communication with the first multimedia terminal, including one or more pre-assigned ports for communication with the first multimedia terminal; the first firewall is configured not to restrict communication between the first multimedia terminal and the one or more pre-assigned ports of the proxy server for communication with the first multimedia terminal, and the proxy server is configured to receive the request to open up said one or more dynamic ports in the second multimedia terminal via one of the proxy server'"'"'s pre-assigned ports and to modify the request to change a source of the request from a network address of the first multimedia terminal and the at least one dynamically assigned port of the first multimedia terminal to a network address of the proxy server and a pre-assigned port of the proxy server for communication with the second multimedia terminal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
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21. A method of making a multimedia call using a communications system that includes a first multimedia terminal configured to use H.323 and a second multimedia terminal configured to use H.323, the method comprising:
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establishing a multimedia call over a shared IP network between said first multimedia terminal and the second multimedia terminal with a communication unit associated with the first multimedia terminal using H.323, said communication unit including a first firewall through which the multimedia call passes, wherein the first firewall is configured to restrict certain types of communication between the first terminal and the shared IP network, and each of the first multimedia terminal and the second multimedia terminal has a number of logical communication ports for transmitting or receiving the multimedia call, including at least one dynamically assigned port; transmitting, with a transmitter associated with the first multimedia terminal, request to the second multimedia terminal to open up one or more dynamic ports in the second multimedia terminal; using a proxy server disposed between the first multimedia terminal and the second multimedia terminal as a proxy for the first multimedia terminal and the second multimedia terminal during the multimedia call, the proxy server having logical communication ports for communication with the first multimedia terminal, including one or more pre-assigned ports for communication with the first multimedia terminal; the first firewall allowing communication between the first multimedia terminal and the one or more pre-assigned ports of the proxy server for communication with the first multimedia terminal; receiving, at the proxy server, the request to open up said one or more dynamic ports in the second multimedia terminal via one of the proxy server'"'"'s pre-assigned ports; and modifying the request to change a source of the request from a network address of the first multimedia terminal and the at least one dynamically assigned port of the first multimedia terminal to a network address of the proxy server and a pre-assigned port of the proxy server for communication with the second multimedia terminal, wherein the modifying is performed by the proxy server.
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Specification