Carsten,
You never need access to the router where you travel, only where the radio sits. As long
as the ports are not blocked, you only need to free these three UDP ports on the radio's
router to use the RRC on the radio end.
The RRC will handle the in and out SIP ports automatically, don't get confused about these
in and out message on the status.
73,
Mitch DJ0QN / K7DX