Ok we did it, after 3 weeks development we have got a real-time synchronized udp based peer-to-peer network engine. It’s really awesome, cheaper and faster than the server based multiplayer. 
Congrats!
Anyone considering UDP to implement a networking protocol needs to understand its limitations:
https://en.wikipedia.org/wiki/User_Datagram_Protocol
In particular, you need understand things like:
It has no handshaking dialogues, and thus exposes any unreliability of the underlying network protocol to the user’s program.
In general (there are some exceptions but not ones worth considering here), UDP is only usable on a LAN and not on WAN (i.e. internet) connections. This is doubly so for mobile devices on cellular networks.
Ok we did it, after 3 weeks development we have got a real-time synchronized udp based peer-to-peer network engine. It’s really awesome, cheaper and faster than the server based multiplayer.
Congrats!
how to connect applications using IP through internet for establishing peer to peer connection?..plz help
Read the previous posts. If the phone acting as server has an external IP (not in 192.168.*.* range and not in 10.*.*.* range) then you can connect to it providing there isn’t a firewall app on the device. In a firewalled situation or IP in before mentioned ranges you have to open apropriate ports on the firewall or router to the devices IP. Clients only need a working internet connection and can be behind firewalls or routers, it’s the server device (the one that is receiving the connection) that is important.
how to connect applications using IP through internet for establishing peer to peer connection?..plz help
Read the previous posts. If the phone acting as server has an external IP (not in 192.168.*.* range and not in 10.*.*.* range) then you can connect to it providing there isn’t a firewall app on the device. In a firewalled situation or IP in before mentioned ranges you have to open apropriate ports on the firewall or router to the devices IP. Clients only need a working internet connection and can be behind firewalls or routers, it’s the server device (the one that is receiving the connection) that is important.