| 摘要 |
<p>The present invention takes its starting point from a data network based system (A), which includes a number of units (1, 1', 1''), belonging to a first category (B), a number of units (2, 2', 2''), belonging to a second category (C), and a firewall (F) operative between said first and said second category units. A first unit (1) belonging to said first category (B), can set up a communications session with a second unit (2) belonging to said second category (C), through the medium of a handshake. Also included is a third unit (3) placed outside the firewall (F). The third unit (3) is able to communicate freely with units belonging to the second category (C) after said second units have registered themselves with the third unit. The first unit sets up an ID-session (S13) with the third unit (3) through the medium of a handshake (H13). The third unit can authenticate the first unit (1) within the ID-session, and thereafter allow the first unit to set up said communications session (S12) with said second unit (2).</p> |
