Resloved-setup multiple lines

Hello, I have an aastra phone with 4 lines and a toll free DID with 4 or more channels. How do I setup the toll free number in aterisk to be able to use all the line on my phone. In other words, if more than one person call at the same time line one will ring then two and so on. Thank you.

set up asterisk normally. Now put your info for the phone’s sip account into the global sip configuration area. blank out the line1-4 configs on the phone.
Result is that all the line buttons are the same, and calls will ‘pile on’ to the next available button.