What is the traffic from the telegram for a voice call?

Question

firewall

On the router, I caught traffic from the local area with IP addresses that do not belong to the local range. This happens during a voice call

Connections from 12.217.* to 91.108.12.* (or 91.108.16.*) to port 599
and from 10.231.* to 91.108.8.*

There are about 300 packets per minute call. I read https://habr.com/ru/post/326566/ but it is not clear why these 12.217 and 10.231 are on my network.

Answer 1

pierced ip.
this is some kind of institution at the address:
st. Kuznetsky Most, 22, Moscow