Asyncsocket connection success in one wifi but not in another one

Question

I am using cocoaasyncsocket (on an iPad) to connect to a tcp/ip server (dotnet on a PC). There are several wifi networks here. When iPad and PC are all in one specific wifi, everything works fine. But if both of them join another wifi, they couldn't connect to each other. Everything else was exactly the same. What it could be? Any suggestions? Thanks a lot.

Answer 1

Figured it out. The wifi that works didn't block the port that I was using but the other wifi did. Opening that port fixes this problem.