为什么我不能通过实际的公共IP连接到服务器?

I am new in network programming and I try to do echo client and server. It works properly via localhost (127.0.0.1) and 192.168.1.35, but doesn't via my actual IP. So it's impossible to connect to my server across the Internet. However, I checked it in my local network and it worked.I am new in network programming and I try to do