Methods and devices for establishing a communication between a first and a second terminal are described. The disclosed technology can be implemented in or by a server or a terminal in communication with the server. The first terminal can to the server, using a first calling identity, a request including connection information and an identifier of the first terminal. Using the identifier, the server can obtain from a database a pair of calling identities including one certified and one non-certified, the pair comprising the first calling identity and a second calling identity. The server can determine, from one of the calling identities and from the connection information, a connectivity mode of the terminal, and determine a routable number on which the terminal can send a communication to the server. The server can route the communication towards the second terminal by presenting a calling identity of the pair and sending the routable number to the first terminal.