Openfire with external STUN

Good Day eveyone,
i have openfire with Astrachat clients, when i want to make a voice call, if the two users behind NAT in two different subnets the phone rings but then the calls drops, here i understood that i need STUN server, i search and found that i can connect my local openfire server with a public external STUN server like (stun.l.google.com) but i dont really know how to do this, is there an guide, Documentation or steps helps me with it, the Main purpose to enable the clients to make a successful voice call.

i appreciate any help Thanks in advance.
Best
Ali

Although I don’t know if this fixes your specific issue, Openfire has support for XEP-0215: External Service Discovery, which is used to make available the location of TURN and STUN servers. You can make available this functionality by installing the Openfire External Service Discovery plugin.

Good Day Guus,

i have installed the Mentioned Plugin, but the problem is still persisting, might you guide me please to configure it correctly, here you are again im explaining what im attending to do:
i need my Astrachat clients to be able to call eachother even if the client is behind a NAT.

Thanks
Best
Ali