Do we need to install Turn server if we use VPN?

We have deployed jitsi solution in our departments and in a videoconference of 10 people all things goes good. Our jitsi server is on local network and the clients connects through VPN to access the local network. At this moment, all videobridge processing are done by jvb.
The question is: is it necessary to implement a Turn server if they can access directly the jitsi server through VPN? I haven’t tested until now with more than 10 people, but Turn server will lead to image quality improvement?
The throughput on jitsi server, with all 10 people connected in a videoconference, is around 25Mbps (resolution i have set to max 480p), CPU is on 20% and there are no other services on that server.
Thank you!

A turn server is needed in case UDP traffic over port 10000 is blocked (by a firewall); so if your VPN allows traffic over UDP/10000 you don’t need a turn server at all.

My 2 cents.

Ok, thank you! Then i will not use it.