I have an unusual configuration from the VoIP operator (neofon):
User name (extensions): 48111111111
Authorization user name (ID) firstname.lastname@example.org
With the above configuration, when I dial the number, the recipient can see that I am calling him, unfortunately he is not able to answer the call.
PS. It is not about a situation where the connection time flies but you cannot hear anyone.
Only the call can not be answered in any way, when I try to answer the call on the phone on which I am calling, I press the green receiver, the phone freezes but still rings.