Asterisk PBX coupled with Siemens 3800

Hi
Vicidial I installed, everything works and I make internal calls but my problem is this: I have an E1 and Siems 3800 I want to configure outgoing and incoming calls via the PABX Siemens
Now I do not know exactly what files to configure asterisk and how the side or the side to Siemens,

Please help me make sure, because it seems urgent

Thanks for your help

WinHop