Communication method to maintain an application session between a terminal and an application server

A communication system comprising an application server comprising at least one application client and one configurable NAT gateway, where the application server is configured to undertake an exchange of candidates with a remote communicating entity following a request through the configurable NAT gateway, where the configurable NAT gateway attributes a public address to the application server, called a peer reflexive address, where this address is associated with the remote communicating entity, so as to establish a first transmission channel ensuring that a first application session is established, wherein a new request for exchange of candidates comprising a history of the previous candidates received from a same communicating entity to the application server results in a configuration of the configurable NAT gateway, so as to modify the association between at least one transmitted candidate and the peer reflexive address of the configurable NAT gateway, and where the system establishes a second transmission channel between the communicating entity and the application server maintaining the first application session.

A communicating entity comprising at least one radio or network module enabling data to be transmitted over at least one interface of the said terminal connected to a network, where the communicating entity comprises a memory in which a history of candidates is recorded and associated with an application server, where the candidates are collected from a server using one of the ICE, STUN or TURN protocols, where the communicating entity comprises at least one calculator to insert in at least one frame of a SIP protocol a data field comprising the history of the collected and memorized candidates, as soon as a transmission channel is generated between the terminal and an application server, and where the communicating entity comprises two modems enabling the presence of at least two access networks to be detected, and two transmission channels to be generated in parallel, in which an application session established between the user terminal and an application server switches from one transmission channel to another whilst keeping the same session identifier.