In a communications network where first and second communication terminals are interconnected via a common communication medium such as a local area network, the terminals jointly establish an infrared light private communication link if they are brought close to each other. The first and second terminals communicate their network addresses to each other either via the local area network or via the private communication link, and establish a session between the communicated network addresses via the local area network if the strength of the infrared-light private communication link at the receiving end is higher than a decision threshold.