I do not know, why it should be so complicated. I did it for another tracking portal:
Normally, you only need the IP and the port (for your device(RUT955)) of the tracking portal.
The port for RUT599 has to be found on the tracking portal. It is compatible with i.e. FMB-204 trackers from Teltonika
If GPS is properly working within the RUT955, go to SERVICES -> AVL -> AVL Server Settings
switch it ON
Hostname: is the IP of the tracking portal
Protocol: TCP
Port: is the port for Teltonika-devices, provided by the tracking portal
A long lasting and not repaired bug/failure: 'send period' and 'collect period' is reversed.
Hope it helps