A bug in Telegram VoIP, which allows you to find out the address of the interlocutor
Introduction
In general, it was in the evening, I made myself an RPI control application from the series “too lazy to get up and turn off the light”)
Therefore, the phone was connected via ADB
Further, everything is more interesting, there was information about the call and a comment of about this kind: “Press 10 on the subscriber’s name to see the information about the call.”
Without thinking twice, I clicked and saw interesting statistics:

Where [UDP_RELAY] / [UDP_RELAY_IN_USE] are the telegram servers through which the traffic passes and the most interesting [UDP_P2P_INET] is the IP address of the interlocutor (if static, then you can already have fun)
We run to support
Immediately I ran to write on support and on Twitter , referring to the telegram tape, but the answer came very surprisingly ...

Then I thought a little and decided to find buns the next day ... On the client for iOS, the debug window looks very interesting, since you can change the conversation settings.

This is all of course good, but if you look at the screenshot above, you will notice that editing the settings on the apple client is and you can turn off P2P and the address of the interlocutor will not be visible.
Well and the last, Clear Voice and bitrate up to 35 kbit - such to itself)