Video conferencing over ip networks

A method for communication, comprising:

• establishing communication links over a packet network;
• receiving uplink audio packets and uplink video packets, which respectively contain audio and video data;
• mixing the audio data from the uplink audio packets to create respective streams of mixed audio data for transmission;
• transmitting downlink audio packets containing the respective streams of mixed audio data;
• relaying the video data in downlink video packets;
• analyzing relative time differences between the mixed audio data and each relayed video data stream;
• generating at least one corresponding synchronization packet based on the analyzed relative time differences between mixed audio data and each relayed video data stream;
• and,
• transmitting the at least one corresponding synchronization packet containing synchronization information for synchronizing the relayed video data in the downlink video packets with the downlink audio packets containing the respective streams of mixed audio data in addition to transmitting the downlink video packets and the downlink audio packets.

A computer program product, comprising a computer usable medium having a computer readable program code embodied therein, said computer readable program code adapted to be executed to implement a method for implementing a method for communication, said method comprising:

• establishing communication links over a packet network;
• receiving uplink audio packets and uplink video packets, which respectively contain audio and video data;
• mixing the audio data from the uplink audio packets to create respective streams of mixed audio data for transmission;
• transmitting downlink audio packets containing the respective streams of mixed audio data;
• relaying the video data in downlink video packets;
• analyzing relative time differences between the mixed audio data and each relayed video data stream;
• generating at least one corresponding synchronization packet based on the analyzed relative time differences between mixed audio data and each relayed video data stream;
• and,
• transmitting the at least one corresponding synchronization packet containing synchronization information for synchronizing the relayed video data in the downlink video packets with the downlink audio packets containing the respective streams of mixed audio data in addition to transmitting the downlink video packets and the downlink audio packets.

A method for communication, comprising:

• establishing communication links over a packet network;
• transmitting uplink audio packets and uplink video packets, which respectively contain audio and video data;
• receiving downlink audio packets containing respective streams of mixed audio data, wherein the downlink audio packets contain mixed audio data from at least one remote computer;
• receiving downlink video packets, which comprise video data from the at least one remote computer;
• and,
• receiving at least one corresponding synchronization packet comprising synchronization information based on relative time differences between the mixed audio data and the video data from the at least one remote computer for synchronizing the video data in the downlink video packets with the downlink audio packets containing the respective streams of mixed audio data in addition to receiving the downlink video packets and the downlink audio packets.

A computer program product, comprising a computer usable medium having a computer readable program code embodied therein, said computer readable program code adapted to be executed to implement a method for implementing a method for communication, said method comprising:

• establishing communication links over a packet network;
• transmitting uplink audio packets and uplink video packets, which respectively contain audio and video data;
• receiving downlink audio packets containing respective streams of mixed audio data, wherein the downlink audio packets contain mixed audio data from at least one remote computer;
• receiving downlink video packets, which comprise video data from the at least one remote computer;
• and,
• receiving at least one corresponding synchronization packet comprising synchronization information based on relative time differences between the mixed audio data and the video data from the at least one remote computer for synchronizing the video data in the downlink video packets with the downlink audio packets containing the respective streams of mixed audio data in addition to receiving the downlink video packets and the downlink audio packets.

A client computer, comprising:

• a user interface;
• and
• a processor, which is configured to establish a communication link over a packet network so as to participate in a video teleconference, and to transmit uplink audio packets and uplink video packets, which respectively contain audio and video data,
• wherein the processor is configured to receive downlink audio packets containing the a stream of mixed audio data, to receive synchronization packets containing synchronization information generated, and to receive downlink video packets containing the video data transmitted by other remote computers in the video teleconference, and to synchronize the video data with the mixed audio data based on the synchronization information for output via the user interface.