Nowadays the trustworthiness, accuracy and availability of time information distributed over networks of every kind is becoming more and more relevant due to the birth of several applications that require accurate and secure time and an high-precision synchronization among their components. Several kinds of threats can be identified in this type of distribution networks, attacks can be run starting from the transmission of the time data until the moment when the information is elaborated by the node. A particular type of networks in which time becomes of primary importance are the 5G telecommunications networks. In order to provide the expected Quality of Service, synchronization is needed in time-precision networks like this.