asa vpn behind firewall

[mloraditch]

we have recently purchased an asa 5510 for vpn purposes. We have a somewhat different situation than most. Our internet and outside world access is provided by our platform provide. They maintain all firewalls, etc. They have assigned us an internet ip which they nat and forward to our 10.x network. Firstly I need to know what ports i need to have them enable to allow use of the cisco vpn client for remote access. Secondly all of the tutorials and such i have seen show the use of two interfaces one with an outside ip and one with an inside ip. we only have the use of our inside ips. How do i setup the asa to work in this situation. can i use just one interface? thanks

[sbilgi]

If this device is behind a firewall using NAT, type an IP address for the NAT Assigned IP Address. For this example, the NAT assigned IP address is 192.168.10.10. If the device is not using NAT or if the ASAs are not behind a firewall using NAT, enter 0.0.0.0.

http://www.cisco.com/en/US/products/ps6120/products_installation_guide_chapter09186a00805a8aa0.html