How to transmit voice through UDP server correctly?

Question

PHP

Good afternoon, I am working on an application that can make "Calls", I know that you can use Sip telephony, using ready-made libraries to connect and transmit voice - ready-made libraries and not bother yourself, but make the server based on the same Asterisk, but I was wondering do everything on my own, and now that's what I have.
There is a Server written in PHP, udp socket is raised on this server, from the client (Xamarin, I have a mobile application),
I connect to the server, for example, I have 2 users, the
server is located at 192.168.10.250:1234, when I connect, I get the following addresses
10.123 .10.13:55666 (i.e. your address from which you connected and the port that the server reserved for it)
10.123.10.14:55777
when users connect and vote on the server, everyone who is on it hears it, it turns out a kind of group chat for everyone.
If I understand correctly, then in order to vote for a specific user, I need to specify his address on the server and port?

Answer 1

Yes: the address serves as a user identifier, the port - for the connection, then the sound transmission must already be written.