The FOI-DST3 provides complete electrical isolation for T3 or DS3 communications.

The unit can be used in areas of high electrical noise or in and out of RF shielded enclosures. The fiber optic cable is not susceptible to interference caused by impulse noise, crosstalk, or EMI. Privacy of communications is also enhanced because the fiber optic cable does not radiate any emissions.

In addition, fiber optic cable offers much longer transmission distances than copper wiring. Traditional T3 coax cabling is limited to a maximum distance of 1100ft (335m), but multimode optics on the unit can extend the distance to 2km, while singlemode optics can further extend the distance to 20km. A typical link consists of two FOI-DST3, one at each end of the network, with a duplex fiber optic cable between them.