A roaming device sends, through a visited network and a proxy network, to a home network, an identifier for a first subscription. The home network sends, through the proxy network, to the visited network, data relating to the first subscription. The proxy network sends to the home network a first temporary address. The visited network sends to the proxy network a second temporary address. The device activates a second subscription. The device sends, through the visited network and the proxy network, to the roaming provider network, an identifier for the second subscription. The roaming provider network sends, through the proxy network, to the visited network, data relating to the second subscription. The proxy network registers the first subscription identifier, the second subscription identifier, the first temporary address and the second temporary address. The proxy network sends to the roaming provider network the first temporary address.