ps aux | grep java
It should print two processes.
1 - WCS core process
2 - WCS manager process
2. Check listening ports.
netstat -nlp | grep java
If you see port 8443 and port 8888, this means core process port 8443 is listening and manager process port 8888 is listening.
3. Check logs.
tail -f /usr/local/FlashphonerWebCallServer/logs/flashphoner_manager.log
It should print that server is started in SS seconds.