How to let sip traffic bypass vpn?

Question

openvpn

There is a gateway on Debian and there are client machines on linux, there is also a remote vpn server (openvpn) how to let clients with sip bypass the vpn to which they connect?
It is advisable to do everything through the gateway, the gateway connects to vpn and everyone goes through the gateway to vpn and let sip bypass.
Or crutches like, each client connects to vpn and start sip bypassing vpn.
I'm still a linuxoid beginner and it's very difficult to understand how to implement it!
I will be glad for any help!

Answer 1

The question is not entirely clear.
As I understood, clients sit in one local area network? What is a VPN used for? To connect local network segments to each other, or to redirect all traffic through another gateway?