which protocol used for developing a chat application over LAN?

Question

I would like to create a chat application(desktop-app) in c++, so which protocol i would need to study and implement. UDP(?)

Please provide me some good thoughts and advices and links also.

Answer 1

UDP protocol is not the best choice for Internet chat program. UDP packets will be blocked by proxies. And UDP doesn't guarantee packets delivery. So probably TCP protocol will be a better choice.

Take a look on Boost.Asio Library. It already contains primitive implementation of chat program.