Method, system and computer program product for determining congestion of a communication link transmitting a media stream over the communication link

A system for determining congestion of a communication link transmitting a media stream transmitted over the communication link from a sender device to a receiving device, the system being adapted to:

• transmitting, with the sender device, media packets into the media stream, each media packet having a packet identifier;
• transmitting, with the sender device, recovery packets into the media stream, each recovery packet adapted to replace a missing packet of the media stream;
• mapping, with the sender device, for each packet in the media stream a packet identifier, a transmission timestamp and a packet size;
• mapping, with the sender device, for each recovery packet the packet identifier of the recovery packet and the packet identifier of the packet the recovery packet is adapted to replace;
• 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 a packet as missing when none of the feedback messages comprises the packet identifier of the packet;
• determining, with the sender device, a packet as recovered when a feedback message comprises the packet identifier of a recovery packet corresponding to the missing packet;
• and
• determining, with the sender device, a packet recovery success rate by dividing a total number of packets determined as recovered within a second sliding window with a total number of packets determined as missing within the second sliding window;
• determining, with the sender device, that the communication link is congested when for the first sliding window of the N transmitted packets the packet recovery success rate is below a congestion threshold.