Method for evaluating an available bitrate (BR1 1 ) over an evaluation path (P1) among one of at least two paths (P1, P2, P3) linking a first endpoint and a second endpoint , the method comprising at the first endpoint : - sending data packets to said second endpoint , - receiving from said second endpoint an acknowledgment message for each sent data packet through one of the at least two paths (P1, P2, P3) selected by the second endpoint for transporting said acknowledgment message according to a path acknowledgment strategy for each sent data packet; - inserting a flag (A) in a first data packet (DP1) out of said data packets to be transmitted to said second endpoint through the evaluation path (P1) so as to force the second endpoint to interrupt the path acknowledgement strategy, whereby, according to said interruption, the second endpoint is forced to send in response to the first data packet (DP1) a corresponding acknowledgement message over the evaluation path (P1) to the first endpoint; - sending said first data packet (DP1) through the evaluation path (P1); - measuring and recording a sending time (t1) of the first data packet (DP1) from said first endpoint ; - receiving an acknowledgment message (Ack) from said second endpoint through said evaluation path (P1) for acknowledging reception of said first data packet (DP1) at said second endpoint , said path acknowledgment strategy of said second endpoint being interrupted when said flag (A) is set in said first data packet (DP1); - measuring and recording an arrival time (t2) of said acknowledgment message (Ack) at said first endpoint ; - assessing the available bitrate (BR1 1 ) from an interval between the sending time (t1) and the arrival time (t2) and from the size of said first data packet (DP1). - sending data packets to said second endpoint , - receiving from said second endpoint an acknowledgment message for each sent data packet through one of the at least two paths (P1, P2, P3) selected by the second endpoint for transporting said acknowledgment message according to a path acknowledgment strategy for each sent data packet; - inserting a flag (A) in a first data packet (DP1) out of said data packets to be transmitted to said second endpoint through the evaluation path (P1) so as to force the second endpoint to interrupt the path acknowledgement strategy, whereby, according to said interruption, the second endpoint is forced to send in response to the first data packet (DP1) a corresponding acknowledgement message over the evaluation path (P1) to the first endpoint; - sending said first data packet (DP1) through the evaluation path (P1); - measuring and recording a sending time (t1) of the first data packet (DP1) from said first endpoint ; - receiving an acknowledgment message (Ack) from said second endpoint through said evaluation path (P1) for acknowledging reception of said first data packet (DP1) at said second endpoint , said path acknowledgment strategy of said second endpoint being interrupted when said flag (A) is set in said first data packet (DP1); - measuring and recording an arrival time (t2) of said acknowledgment message (Ack) at said first endpoint ; - assessing the available bitrate (BR1 1 ) from an interval between the sending time (t1) and the arrival time (t2) and from the size of said first data packet (DP1). <EOS>