Abstract: An improved phone plug comprises a housing having a rear-receiving end and a plugging end, a number of inductors and conductors. The plug-receiving socket is formed in the rear-receiving end and adapted to receive a modular phone plug; the plugging end being so formed that the plugging end can be plugged into a regular phone jack coupled to the phone line system including the data network. The conductors are mounted in the housing and have first ends and second ends; the first ends projecting into the plug-receiving socket for engaging a contact of the modular phone plug when the modular phone plug is inserted into the plug-receiving socket; the second ends coupled respectively to the plugging end through the inductors.