i cant figure out to open my nat as i dont use a router i use a 3g huawei e1550 wireless modem.i rang 3 up to ask to open nat and they said they dont do that.help me
You can't. You need a router to do that. The only purpose of the modem is to act as a converter of an analog signal to a digital signal. It serves no other purpose in your network. Just go out and get a cheap router to do that for you.