Through this diploma thesis, it is shown how telephone signaling has developed from the very beginning until today. The beginnings of the emergence and development of signaling, the problems and shortcomings that were present, and the ways and protocols of how networks developed are visible. A major development in signaling occurred with the transition from CAS to CCS signaling. The most important representative of signaling is signaling system number 7, which is also described in the paper. SS7 has remained the basis of all types of signaling to this day. Development procedures are explained, as well as individual parts of each protocol. It is explained how individual protocols and which parts of them were transported to newer, more stable and faster protocols. It is evident what differences and changes have led to significant improvements in networks over the years, such as developments from the initial telephone user part (TUP), to ISUP, BICC and SIGTRAN. The call control function (CCF) because it is well defined is still retained in all protocols. The main problems that were present during the communications were described, and how a more stable and better solution was reached. It can be seen how much the transmission speeds and the way certain signals are transmitted have increased significantly, as well as how much the demand for faster, better and more stable connections is constantly increasing. SIGTRAN has improved signaling methods by developing a set of protocols that provide a more reliable service for the SS7 system, and is still a key element in the evolution of new voice service services. The assumption is that CCF functions will continue to be retained in telecommunications systems, and this primarily implies a new IP multimedia subsystem.