Mavlink router endpoints on air unit

[Alvin]

HereLink Android app - access to MavLink

you need to send one thing to make the socket latch onto you, after rereading the code, it does NOT need to be a mavlink packet… so you could send a 1 byte packet, and that should be enough. the other option is to modify the mavlink router config via the herelink OEM settings. then you can define anything you want in that config file

For the 14551, seems like you need to send something as acknowledge signal.
Not sure if this is what happened in your case.

What will be using the extra UDP endpoint? How is it connecting to the air unit?