@Mahadevan So let me see if I get your actual use case. You want to allow users to chat in application but not call or video chat?
-If that is the case you could possibly do some layer7 rules around video and WhatsApp just by reading packet captures of where the individual data is going. In my experience video goes to a different end https:// xx server then chat.
Let me know if you need help dissecting the captures. Feel free to direct message me if you don't want to share the captures wifely.
