After starting an emulator instance, I can use adb to control it. But i don't need to specify the listening port of the emulator. My question is how does them connect together? Use default port? or something else.
It scans the even numbered ports starting at a specific range and attempts to connect. The emulator takes control of a port each.
Basically as said on http://developer.android.com/guide/developing/tools/emulator.html In the network -port section it says
The console port number must be an even integer between 5554 and 5584, inclusive. +1 must also be free and will be reserved for ADB