They are aware of the issue: http://forum.square-enix.com/ffxiv/t...P2P-throttling , people make a lot of threads about this issue also not only RCN has that issue other ISP have that issue aswell.
I agree it should have been put in being addressed but theres a lot of threads about this issue and theres already an official one which I linked.
For now I recommend using a VPN until this is fixed.
I had my hopes that the issue was fixed when I saw it in the resolved area but its not fixed :x