A method for preserving a transmission rate of second data transmitted by a first terminal destined for a second terminal attached to at least one access device in a communications network. A communications network node capable of routing the second data identifies an inability of the at least one access device to send first data received from the first terminal to the second terminal, processes the first data received from the first terminal during the identified period of inability of the at least one access device, and transmits to the first terminal a notification indicating that the first stored data is not subject to congestion.