The recommendation in view of Recommendations R.51 bis and R.54, that, for the technical supervision of international telegraph circuits, it is necessary to make periodic character error rate measurements on their international sections when they are made up of two or more channels; that certain Administrations consider it desirable to have available apparatus for making simple measurements automatically and periodically, giving an indication of the performance rating and transmitting an alarm when this rating exceeds the limits permitted for automatic switched channels.