A data communication method between a radio communications equipment item intended to be embedded in a roaming carrier, and a gateway connected to a network, the data being organised in the form of packets comprising at least a first network header, called the internal header, corresponding to a network link between a local communications equipment item belonging to a local network embedded onboard said carrier and a remote communications equipment item connected to said network and a second network header, called the external header, corresponding to a network link between said radio communications equipment item and a home agent connected to the gateway, said method being characterised in that it comprises at least: - an initial information exchange phase comprising: ➢ the transmission by the radio communications equipment item to the gateway or the reception by the gateway from the radio communications equipment item of at least one predictable field out of the fields of the external header and of the internal header, a predictable field being a header field the value of which is fixed or constant whatever the communication coming from or going to the radio communications equipment item, ➢ the reception by the radio communications equipment item from the gateway or the transmission by the gateway to the radio communications equipment item of at least one predictable field of the external header, - a phase of transmission of at least one data packet comprising: ➢ the deletion of the external header and of the internal header of said at least one data packet, ➢ the generation, in said at least one data packet, of a header of a level lower than a network layer comprising at least one non-predictable field out of the fields of the internal header, ➢ the transmission of said at least one data packet. - an initial information exchange phase comprising: ➢ the transmission by the radio communications equipment item to the gateway or the reception by the gateway from the radio communications equipment item of at least one predictable field out of the fields of the external header and of the internal header, a predictable field being a header field the value of which is fixed or constant whatever the communication coming from or going to the radio communications equipment item, ➢ the reception by the radio communications equipment item from the gateway or the transmission by the gateway to the radio communications equipment item of at least one predictable field of the external header, ➢ the transmission by the radio communications equipment item to the gateway or the reception by the gateway from the radio communications equipment item of at least one predictable field out of the fields of the external header and of the internal header, a predictable field being a header field the value of which is fixed or constant whatever the communication coming from or going to the radio communications equipment item, ➢ the reception by the radio communications equipment item from the gateway or the transmission by the gateway to the radio communications equipment item of at least one predictable field of the external header, - a phase of transmission of at least one data packet comprising: ➢ the deletion of the external header and of the internal header of said at least one data packet, ➢ the generation, in said at least one data packet, of a header of a level lower than a network layer comprising at least one non-predictable field out of the fields of the internal header, ➢ the transmission of said at least one data packet. ➢ the deletion of the external header and of the internal header of said at least one data packet, ➢ the generation, in said at least one data packet, of a header of a level lower than a network layer comprising at least one non-predictable field out of the fields of the internal header, ➢ the transmission of said at least one data packet.