Abstract: A high-bandwidth direct communication path between two clients is used for voice or video calls over the Internet. An opening or a window in a firewall is made for the direct path by sending a null packet out from inside the firewall. The null packet can be a UDP packet directed to a UDP port of the other client. Initially, each client makes a TCP connection to port 80 of an external manager. Each client registers its UDP port number with the external manager. A call request from one client to the external manager results in a message from the external manager to the other client. The other client then creates the window in its firewall by transmitting the null UDP packet. Then the external manager is notified and tells the calling client to begin sending UDP packets directly to the other client through the firewall window.

Abstract: A voice-over-Internet-Protocol (VoIP) client codes audio data as printable ASCII characters, then embeds the ASCII audio data inside a cookie that is sent over the Internet within an HTTP GET message. The GET message is sent to a server acting as a call proxy or external manager that forwards the audio data to a remote client. Return audio data is sent back to the client in the normal data field of an HTTP response message from the server. When the client receives the HTTP response, it sends another GET message without audio data, allowing the server to send another response. This empty GET allows VoIP to pass through strict firewalls that pair each HTTP response with a GET. For secure-sockets layer (SSL), client and server exchange pseudo-keys in hello and finished messages that establish the SSL session. Audio data is streamed in SSL messages instead of encrypted data.

Abstract: A high-bandwidth direct communication path between two clients is used for voice or video calls over the Internet. An opening or a window in a firewall is made for the direct path by sending a null packet out from inside the firewall. The null packet can be a UDP packet directed to a UDP port of the other client. Initially, each client makes a TCP connection to port 80 of an external manager. Each client registers its UDP port number with the external manager. A call request from one client to the external manager results in a message from the external manager to the other client. The other client then creates the window in its firewall by transmitting the null UDP packet. Then the external manager is notified and tells the calling client to begin sending UDP packets directly to the other client through the firewall window.

Abstract: A high-bandwidth direct communication path between two clients is used for voice or video calls over the Internet. An opening or a window in a firewall is made for the direct path by sending a null packet out from inside the firewall. The null packet can be a UDP packet directed to a UDP port of the other client. Initially, each client makes a TCP connection to port 80 of an external manager. Each client registers its UDP port number with the external manager. A call request from one client to the external manager results in a message from the external manager to the other client. The other client then creates the window in its firewall by transmitting the null UDP packet. Then the external manager is notified and tells the calling client to begin sending UDP packets directly to the other client through the firewall window.

Abstract: A voice-over-Internet-Protocol (VoIP) client codes audio data as printable ASCII characters, then embeds the ASCII audio data inside a cookie that is sent over the Internet within an HTTP GET message. The GET message is sent to a server acting as a call proxy or external manager that forwards the audio data to a remote client. Return audio data is sent back to the client in the normal data field of an HTTP response message from the server. When the client receives the HTTP response, it sends another GET message without audio data, allowing the server to send another response. This empty GET allows VoIP to pass through strict firewalls that pair each HTTP response with a GET. For secure-sockets layer (SSL), client and server exchange pseudo-keys in hello and finished messages that establish the SSL session. Audio data is streamed in SSL messages instead of encrypted data.

Abstract: A Voice-over-Internet-Protocol (VoIP) system includes clients that make management connections to an external manager server using web-browsing protocols. A discovery process tests a variety of transport methods by sending packets using different protocols to several ports of the external manager. Some packets may be blocked by firewalls, while other packets are allowed to pass through. Successful packet replies indicate transport capabilities of the client. When a client makes a VoIP call to another client, the external manager compares transport capabilities of the two clients and selects a transport capability that is common to both clients. Transport methods include direct client-to-client connections using TCP or UDP to an arbitrary port or well-known port 80 or 443, and indirect using a voice-proxy server that each client connects to using web standards such as HTTP or SSL. When a client can make only outgoing connections, that client initiates the connection.

Abstract: A voice-over-Internet-Protocol (VoIP) client codes audio data as printable ASCII characters, then embeds the ASCII audio data inside a cookie that is sent over the Internet within an HTTP GET message. The GET message is sent to a server acting as a call proxy or external manager that forwards the audio data to a remote client. Return audio data is sent back to the client in the normal data field of an HTTP response message from the server. When the client receives the HTTP response, it sends another GET message without audio data, allowing the server to send another response. This empty GET allows VoIP to pass through strict firewalls that pair each HTTP response with a GET. For secure-sockets layer (SSL), client and server exchange pseudo-keys in hello and finished messages that establish the SSL session. Audio data is streamed in SSL messages instead of encrypted data.

Abstract: A high-bandwidth direct communication path between two clients is used for voice or video calls over the Internet. An opening or a window in a firewall is made for the direct path by sending a null packet out from inside the firewall. The null packet can be a UDP packet directed to a UDP port of the other client. Initially, each client makes a TCP connection to port 80 of an external manager. Each client registers its UDP port number with the external manager. A call request from one client to the external manager results in a message from the external manager to the other client. The other client then creates the window in its firewall by transmitting the null UDP packet. Then the external manager is notified and tells the calling client to begin sending UDP packets directly to the other client through the firewall window.

Abstract: A high-bandwidth direct communication path between two clients is used for voice or video calls over the Internet. An opening or a window in a firewall is made for the direct path by sending a null packet out from inside the firewall. The null packet can be a UDP packet directed to a UDP port of the other client. Initially, each client makes a TCP connection to port 80 of an external manager. Each client registers its UDP port number with the external manager. A call request from one client to the external manager results in a message from the external manager to the other client. The other client then creates the window in its firewall by transmitting the null UDP packet. Then the external manager is notified and tells the calling client to begin sending UDP packets directly to the other client through the firewall window.