Most current networks employ electronic processing and use the optical fibre only as a transmission medium. Switching and processing of data are performed by converting an optical signal back to electronic form.
Electronic switches provide a high degree of flexibility in terms of switching and routing functions.
The speed of electronics, however, is unable to match the high bandwidth of an optical fiber (Given that fibre has a potential bandwidth of approximately 50 Tb/s – nearly four orders of magnitude higher than peak electronic data rates).
An electronic conversion at an intermediate node in the network introduces extra delay.
Electronic equipment is strongly dependent on the data rate and protocol (any system upgrade results in the addition/replacement of electronic switching equipment).