A system is provided for characterizing optical fibers carrying signal traffic. The cam assemblage includes a cam mechanism for rotational movement and the driving mechanism also being operably connected to the at least one valve of the engine to move the at least one valve between a valve closed position and a valve open position and between the open position and the closed position in a manner directly related to the rotational movement of the cam mechanism. The subscriber profile management system further includes an administration module that administers TTL limits, TTL limit database that store TTL limits, a subscriber profile database that stores subscriber profiles, a usage measurement database that stores usage measurements, and a TTL limit reference module that administers TTLs when a subscriber profile and TTL limit are transmitted.