Inbound routes with no cdr

Hi all,

I have an elstix platform with freepbx 2.6

I use it as a fax server with nvfaxdetect, all works fine except a couple of problems. I’d like yours suggestions:

1 I’d like to have only outbounds faxes cdr entry in mysql. I think i have to try something custom, like a custom app and a custom context, adding something like
exten => NUMBER,n,NoCdr() . Anyone can help me with some more details?

2 Faxes go out and in through a quescom device, sip trunk, but it happens that i loose the callerid and i can see quescomdevice instead, and destinantion has s,
any advice?
Does it has to do with the To: of From: header of sip packet?

Thanks all