You're probably SoL for a time then, as shitty as that sounds... I think logging in from another computer could help, it was random but occasionally that worked for me, even on the same connection.
If not, try having someone you trust log you in and move you.
Otherwise, very few solutions worked for me, and any that did or were suggested were temporary at best or simply changed which zone would DC me.
My brother did something to my connection from my computer that temporarily fixed it, but in the end absolutely nothing we did, including buying a new router, fixed the issue... it just... stopped happening.
You can check here for all the ***I went through:
http://www.bluegartr.com/threads/125762-Unable-to-log-into-Characters-in-XI.
And any solutions that may have worked for me might work for you
Edit: Can drive to a place in your neighboorhood with free Wi-Fi and log in from there. I did that once.