I must to use both "type=peer" and "type=user"

I am trying to connect my ISDN-line to Asterisk.
I have a FritzBox7170 that I can use as a ISDN-IP-Gateway.

If I create a trunk using type=peer, I can register Asterisk as SIP client to FritzBox7170.
If I create two trunks (one type=peer + one type=user as explained in most guides), I cannot register Asterisk as a SIP client to FritzBox7170.

Can I use only one trunk (type=peer) to receive/make calls ???

I tryed only one trunk, but wher I try to make a call i hear “all circuits are busy…”

I tryed to configure a hardware SIP Phone as a SIP client to FritzBox7170 and it work perfectly. I can receive and make calls.

In most cases, you only need type=peer. In most of those cases, you need insecure=invite (because the other end either won’t use a password, or doesn’t use the same one).

Note also that type=friend is the equivalent of type=peer and type=user.