I have one analog line coming into a TDM01B on my Asterisk Server. I was suprised to find that, by default, AAH answers the incoming line and then rings the SIP phones according to my ring group settings. I just assumed that the standard operation would be that it would not answer the analog line until someone picks up a ringing SIP phone.
The reason I want it to work this way is to save the caller toll charges if nobody answers. I also want to use the call forward feature my analog phone line provider has so that if someone calls in and nobody answers after about 15 seconds, it automatically transfers to my cell phone. It works via my analog provider automatically as long as the TDM01B does not answer the line until someone picks up a ringing SIP phone.