IEC 101,103,104 protocole, what is DNP protocole

DNP3 is Distributed Network Protocol, an open protocol designed for fast, efficient, secure communication, primarily on SCADA systems. It has evolved from other protocols and is widely used across many systems.

Best bet is to start reading at http://www.dnp.org/, there is way too much to the protocol to post on a forum.

These are all communications protocols for the control of electric power systems. If you will just google each of them, you will get a more complete answer than I can give you, much faster than I can type it.