Getting remote Desktop to local pc

Hi,

I am trying to do this:
I want to pull the display of a sun machine on to my local pc.

network is like as:

    Local pc ----Router-------Firewall-------sun machine
                  Cisco 1750   Netscreen

I am using Xmanager on my pc.
On the f/w ihave opened tcp port 6000 but still no remote display.

Do ihave to open some other port on the firewall? Also do i have to
open a tcp/ udp port on the cisco router.

Please advice
TIA

amit kaushal