Configuration steps for remote desktop via verizon fios



I need to access my computer which is connected to the standard issue Verizon
FIOS router. While I am on the Network locally I can remote desktop to the
this system running Windows XP.

From a remote location I cannot connect. Previously I was able to do this
with my Optimum Online service without making any further configuration steps.
I used the following syntax http://ISP_Assigned_IP_Address:port_number/tsweb/

Any suggestions?
.