Tapped out

Phone-tapping used to mean a quick click of mouse to extract the right conversations from computerised exchanges. VOIP services are based on the session initiation protocol (SIP), a TCP/IP-based application layer signaling protocol that lets computers find each other on the Internet. Tapping only becomes easy if the SIP VoIP call is made from a fixed location with a fixed Internet address connecting directly to a big Internet provider's access router. Interception and extraction would then require hardware in the ISP's network capable of identifying the media packets and converting them back to audio if the hardware can reverse any encryption used on the media.