Systems and methods of dynamically adapting multimedia data transmit rates of data senders to available bandwidths of data receivers, in which the available bandwidths are estimated by the data senders using at least reception quality feedback information provided in real-time transport control protocol (RTCP) report packets. The data senders can obtain several bandwidth estimation parameters, such as a packet loss ratio and a round trip delay, from the reception quality feedback information, as well as multimedia data transmit rates from the data senders to the data receivers, and obtain estimates of the available bandwidths of the data receivers using at least the bandwidth estimation parameters and multimedia data transmit rates. Further, using the estimated available bandwidth, the data senders can dynamically adapt the multimedia data transmit rates to the available bandwidths for more reliably achieving the quality of experience (QoE) desired and/or required for multimedia data transmissions.