I need some help

I am new to asterisk and I have very little experience, I have a very big problem. I install a central with elastix, if I call an extension number, rings another. For example, I call the 9003 and the 9007 rings, but if I call from the 9003 to another phone, the screen shows 9003, the 9003 is not forward, case with several extensions.

Has this ever happened to any of you?