Method of communication between a first communicating entity connected to a first network (INTERNET) thanks to a first gateway NAT of a first local network and an application server (SERV_A), said application server (SERV_A) being associated with a gateway NAT that can be configured (NATO) making it possible to have at least one address of at least the first gateway NAT (NAT1, NAT2) correspond with at least one public address (S1, S2) of the first communicating entity, called reflexive address pair (AR-P), comprising the following steps: • Establishing of a first candidate exchange sequence, said candidates comprising at least one IP address and a port, comprising: ∘ A collecting of candidates by the first entity from a server implementing the ICE, STUN or TURN protocols so as to be reached by a remote server (SERV_A) by the intermediary of the first gateway NAT; ∘ An exchanging of candidates between the first entity and the application server (SERV_A) resulting in the transmission of the reflexive address pair (AR-P) between the gateway NAT that can be configured (NATO) and the first gateway; ∘ A transmission by the first entity of a history of candidates attributed to the first entity to the application server (SERV_A); ∘ Verification of the channels between pairs of candidates established between the first entity and the application server (SERV_A); • Generating a first transmission channel providing the establishing of a first application session; • Detecting by the first communicating entity of a new access network comprising a second gateway NAT or of a reconnection to the first access network following a disconnection, resulting in the establishing of a second sequence of exchanges of new candidates comprising steps similar to the first sequence; • Automatic configuring of the gateway that can be configured (NATO) by a function of the application server (SERV_A) in such a way as to modify the correspondence between the source address of the first or of the second gateway NAT (NAT1, NAT2) with the reflexive address pair (AR-P) of the gateway NAT that can be configured (NATO) using the history of the candidates transmitted by the communicating entity; • Generating a second transmission channel between the first communicating entity and the application server (SERV_A) providing the maintaining of the first application session (SA 1). • Establishing of a first candidate exchange sequence, said candidates comprising at least one IP address and a port, comprising: ∘ A collecting of candidates by the first entity from a server implementing the ICE, STUN or TURN protocols so as to be reached by a remote server (SERV_A) by the intermediary of the first gateway NAT; ∘ An exchanging of candidates between the first entity and the application server (SERV_A) resulting in the transmission of the reflexive address pair (AR-P) between the gateway NAT that can be configured (NATO) and the first gateway; ∘ A transmission by the first entity of a history of candidates attributed to the first entity to the application server (SERV_A); ∘ Verification of the channels between pairs of candidates established between the first entity and the application server (SERV_A); ∘ A collecting of candidates by the first entity from a server implementing the ICE, STUN or TURN protocols so as to be reached by a remote server (SERV_A) by the intermediary of the first gateway NAT; ∘ An exchanging of candidates between the first entity and the application server (SERV_A) resulting in the transmission of the reflexive address pair (AR-P) between the gateway NAT that can be configured (NATO) and the first gateway; ∘ A transmission by the first entity of a history of candidates attributed to the first entity to the application server (SERV_A); ∘ Verification of the channels between pairs of candidates established between the first entity and the application server (SERV_A); • Generating a first transmission channel providing the establishing of a first application session; • Detecting by the first communicating entity of a new access network comprising a second gateway NAT or of a reconnection to the first access network following a disconnection, resulting in the establishing of a second sequence of exchanges of new candidates comprising steps similar to the first sequence; • Automatic configuring of the gateway that can be configured (NATO) by a function of the application server (SERV_A) in such a way as to modify the correspondence between the source address of the first or of the second gateway NAT (NAT1, NAT2) with the reflexive address pair (AR-P) of the gateway NAT that can be configured (NATO) using the history of the candidates transmitted by the communicating entity; • Generating a second transmission channel between the first communicating entity and the application server (SERV_A) providing the maintaining of the first application session (SA 1).