Dear Sirs,
My nodejs solution based on multiple successful projects includes
- different message types (message texts, UI updates, Map signs),
- sound alerts,
- web notifications (a small popup box shows up in modern web browsers, even if the browser window is minimized).
According to statistics, an average server can serve up to 2,000 simultaneous websocket connections seamlessly.
So I can offer a code providing fully customized real-time communication with low network traffic and device usage, multiple ways to communicate back and forth, with audio and visual notifications added. If you are interested feel free to contact me.