A technique to transmit data from a sender to a receiver via a network, preferably a LAN and/or the Internet etc., where the sender transmits the data to a base station, and where the sender is verified by a server, in particular a AAA-server etc. In order to prevent the transmission of data from an illegitimate sender at the expense of a legitimate sender to the greatest extent possible, the server transmits verification data from the server to the sender and/or base station.