A method of activating at least one processing entity from among a plurality of entities situated on the path of a data of a session between a terminal of a user and a server of a services provider. The terminal and the server are attached to a communications network. In the method, the terminal: sends to the server an identification message to receive identifiers of entities of the plurality, which are added to the message by the entities; receive from the server an acknowledgement message including the identifiers included in the identification message; select at least one identifier from among those received from the server; and send to the server a message relating to the activation of entities from among the plurality.