Is there any chat app for local network (works without Internet connection) like netmeeting in windows xp?

Question

Is there any chat application works on Windows 10 or 7 similar to netmeeting in windows xp, which

supports:

1. works without Internet connection, works on LAN (local Network is enough to run it).
2. transferring files.
3. remote control
4. open source and free.

The application "netmeetings" is exist in windows XP but not in later versions of Windows OS, so is there any alternative to this old application with these features and works on Windows 10 ???