Send data from phone to phone over the Internet?

Question

Is there a way to actually communicate between two Android devices over the Internet without having any service between the two devices?

How to send something to device2 from device1 without the need for "in the middle" on any other server or something else?

Another question: I tried to ping my phone over the Internet (just using the IP address), which did not work, as it seems that my ISP uses the same WAN-IP for all phones, or at least a few of them. So is there a way to actually ping or send data to your specific phone, just using the IP address or my Google account or something like that?

Answer 1

Almost all of the end user devices are behind the ISP, and many of them are behind many devices in the network hierarchy; Thus, it is extremely rare that the end user device has a public IP address.

Even if you want to start a public server for listening to requests, you do not need to publish the IP address of your device, and a redirect is created on the router that redirects certain requests to your device.

Having said that, you cannot communicate between two end devices using the Internet without a common server between them.

Thus, your possible solution could be : (If you do not want to use an intermediate server), you can send data using mms directly to a mobile phone number.

Answer 2

BitTorrent is a P2P and works because of the common WAN IP addresses. You can implement something similar, but you need to know the IP addresses of devices A and B and the ports on which the message should occur. These ISPs usually provide dynamic port forwarding.

Answer 3

You must attach a static ip to one of the devices. If you connect to the Internet from your mobile service provider, providers usually do not provide a static ip. You can get your ip dynamically and send to another device via sms.

Answer 4

I think you can use DDNS on your modem.