Hello,
Since you have dynamic IP from Verizon, you may need to install software like DynIP (http://dynip.com/ ) or DynDNS (http://dyn.com/dns/
). These software will provide you a hostname you can access from outside the building. The software will take care of the changes of IP from Verizon.
You should also configure port forwarding on the FIOS router, to forward traffic on the 1433 port to the XP computer that has installed SQL Server.
Hope this helps.
Regards,
Alberto Morillo
SQLCoffee.com
