A communication protocol is a system of rules that allow the entities of a communication system exchange information. They can cover authentication, correction, error detection and signaling. They are basically used in computer networks and these can not work without it.
Thus,
The statements that are true are:
1. A communication protocol is set up to stablish a relationship between the sender and recipient of the message.
3. A communication protocol does not cover etiquette that needs to be followed during professional conduct.