Thanks, this Shareport utility can communicate through my firewall.
I use the 323 through a DIR-655 router. I tested the SharePort of the router and it's working well, visible from my laptop.
I want, however, use the SharePort of my DNS-323, but it is not visible outside the storage: neither through the router, nor directly connecting the storage with my laptop...
Should/can I downgrade maybe the firmware to 1.09?