Send/Receive Chatterbox messages

Hello

There's two different applications, lets say

• Tracker - app that works as GPS Tracker and send information to Wialon using specific protocol
• Client - app that works with Wialon using Remote API and SDK

If you're going to create first type app you no need information about SDK, getMessages and "__app_chatterbox_msg".
You need specific messages format that you'll send to wialon server and get response from server (protocol).
For example, you can use Wialon IPS protocol. When you send 'Message to driver' using it - you'll get new text message in Wialon (both in Hosting and Chatterbox)

I have managed to send messages to the server using the Android client so that part works fine.

Now I'm trying to receive messages from the server(Chatterbox client) to the tracker.
What port should I listen on for the receiving of messages, or should I just start a bufferedReader on the sockets inputstream?