This is how the ring works (from what i can tell) and it can be useful.
You have to be in a region under your nation's control. When you use the ring, it will warp you to the outpost in that region.
Its lazy i know, but i use it to warp from Konschtat highlands to Valkurm dunes when i'm done camping Stray Mary, so I can get to the moogle in Selbina a bit faster, change jobs and warp home with BLM.
Its not great, but its just another means of faster transport.
I don't know if you have to have done the OP quest in that region for it to work, but my guess is you do. I haven't used it in a region I haven't done the supplies quest in.
Hope this helps clear things up a bit :)