Thirdlane Connect has been tested and works well with Coturn - free open source server that acts as both STUN and TURN servers. You can read about STUN and TURN in this post.
Coturn can be installed on the same server as the Thirdlane PBX or Thirdlane Multi Tenant PBX, or on a separate server dedicated to STUN/TURN processing.
There are few cases when you should install Coturn on a separate server: