Umts Voip

I have an old ADSL wireless router (Allied Telesyn AT-ARW256E) that I used before when I was using an ADSL Internet connection.

But lately I switched to 3G/HSDPA mobile broadband Internet, and connect my Win XP Desktop PC directly with a USB modem HSDPA. I want to share the 3G internet connection in my office with my laptop and a VoIP gateway using Windows ICS.

Is it possible that I can reuse my old router to share broadband WiFi Internet, via two ethernet ports and wifi?

So far, I can not make it work, but when I use a LAN switch instead of the ADSL WLAN router, I can share the Internet.

Please help me how I can reuse my wireless ADSL router that I want to access the Internet from other devices, not only using the ethernet ports, but also via WLAN.

Thank you very much!

ICS is a routing protocol, so you want to disable DHCP in the router and connect the router to the computer by ICS is one of the router's LAN (not WAN) taken.