This means that random signal storage, transmission, and switching are all handled in the optical domain. An all-optical Ethernet switch is a network switch whose service ports are entirely optical, meaning every interface uses fiber rather than copper. They can function as core, aggregation, and access devices on campus networks and connect to upstream and downstream devices. This tutorial covers the all-optical switches themselves – the various types, how they differ from electronic switches, where they sit in networks, what functions they perform, how they're controlled, and what they can and can't do. " in Devotions Upon Emergent Occasions, Meditation XVII.