For my question let us just consider two telephone (POTS) connected by wire, junction boxes, several telephone switches/exchanges etc without any wireless connection. One telephone is in continent A and other is in continent B. I understand how sound is converted into electric current by a microphone in a telephone and how a speaker reverses the process of electric current to sound on far end. What I am still confused is how electric current from one telephone reaches the far end telephone instantaneously. 1) Does the electron travel from one telephone to other that fast? or 2) Does energy from electron travel from one telephone to the other? or 3) Is it due to transfer of ElectroMagnetic energy due to electric current? Does electromagnetic wave go along the telephone wire and junction box and through the telephone switches? 4) is it something else? I would appreciate if someone can help me understand the theory behind it.