Hello everyone! I'm totally new on this forum so if I break some rules, let me know 
I have one question, I'm designing android app that will control arduino, it will be server so I connected its ethernet shield, and did coding etc
I have one problem, when I try to send socket from app to arduino it gives me null pointer exception, I belive it is some kind of network problem, arduino is conected via ethernet cable, and android smartphone is wirelessly connected to a different network router,, is it possible to establish communication that way or do they both HAVE to be on same router, because my lap also connected to same network as phone cant access page served by Arduino? What am I doig wrong?
p.s. I'm kind of desperate... 