Tunnel proxy for protecting data access

摘要

Device for protecting the data access or a first member (7) or members of a first sub-network of an automation network (1) to a second member (12) or number of members (12, 13) in a second sub-network of the network, by means of a so-called transparent tunnel-proxy (15) that is pre-connected in front of the second sub-network. Thus data can be transmitted over an unsafe network in a safe manner with the tunnel proxy acting as a representative for either the first or second network member. An independent claim is made for a network coupling unit with a transparent tunnel-proxy for securing data transmission between sub-networks of an automation network.