Method, system and computer program product for initiating downspeeding in a videoconferencing session

A system for downspeeding of a media stream transmitted over a communication link from a sender device to a receiving device, the system being adapted to mapping, with the sender device, for each packet in the media stream a packet identifier, a transmission timestamp and a packet size;

• transmitting for each packet received at the receiving device a feedback message to the sender device, the feedback message comprising the packet identifier and an arrival timestamp;
• determining, with the sender device, a transmission rate for a first sliding window of N transmitted packets by dividing a packet size sum of the N transmitted packets with a time difference between the transmission time stamp of the last of the N transmitted packets and the transmission time stamp of the first of the N transmitted packets;
• determining, with the sender device, a received rate for the first sliding winding of the N transmitted packets by dividing the packet size sum of the N transmitted packets with a time difference between the arrival time stamp of the last of the N transmitted packets and the arrival time stamp of the first of the N transmitted packets;
• and
• initiating, with the sender device, downspeeding of the media stream when for the first sliding window of the N transmitted packets the difference between the transmission rate and the received rate divided by the transmission rate is above a first downspeeding threshold.