Some embodiments relate to a method implemented by a first terminal for setting up a session with a second terminal. An identifier of a session server is obtained at least from a subscriber device in the first terminal which comprises a subscriber identifier and an operator identifier. A session request and an identifier of the second terminal are sent to the server. At least one instruction is received from the server and a message comprising a first set, relative to the first terminal, of at least one characteristic parameter of the requested session is generated in accordance with at least one instruction received and sent to the server. A message is received from the server comprising a second set of at least one characteristic parameter of the requested session, the second set relating to the second terminal and having a non-zero overlap with the first set.