When used as a part of an ICE solution, for VoIP connectivity, this TURN server can handle thousands simultaneous calls per CPU (when TURN protocol is used) or tens of thousands calls when only STUN protocol is used. For virtually unlimited scalability a load balancing scheme can be used. The load balancing can be implemented with the following tools (either one or a combination of them):
DNS SRV based load balancing;
built-in 300 ALTERNATE-SERVER mechanism (requires 300 response support by the TURN client);
network load-balancer server.
Traffic bandwidth limitation and congestion avoidance algorithms implemented.
This project can be successfully used on other *NIX platforms, too, but that is not officially supported.
The implementation is supposed to be simple, easy to install and configure. The project focuses on performance, scalability and simplicity. The aim is to provide an enterprise-grade TURN solution.
To achieve high performance and scalability, the TURN server is implemented with the following features:
High-performance industrial-strength Network IO engine libevent2 is used
Configurable multi-threading model implemented to allow full usage of available CPU resources (if OS allows multi-threading)
Multiple listening and relay addresses can be configured
Efficient memory model used
The TURN project code can be used in a custom proprietary networking environment. In the TURN server code, an abstract networking API is used. Only couple files in the project have to be re-written to plug-in the TURN server into a proprietary environment. With this project, only implementation for standard UNIX Networking/IO API is provided, but the user can implement any other environment. The TURN server code was originally developed for a high-performance proprietary corporate environment, then adopted for UNIX Networking API
The TURN server works as a user space process, without imposing any special requirements on the system