Method for dynamically configuring entities of a communications network for routing data from a visitor terminal

A method for configuring a terminal of a client user of an operator managing a first communications network. The method is implemented prior to the attachment of the terminal to a second communications network, for which transmission resources are temporarily used for routing data from the terminal to a remote server. The method includes receiving, from a control entity of the first network, a management instruction relating to the attachment of the terminal to the second network for a geographical zone. The method further includes configuring a data item relating to the control of the attachment of the terminal on the basis of the received management instruction, and transmitting, to the at least one terminal, at least one configuration parameter for attaching the terminal to the second network.