Iax problem?

I have problems getting my iax up.

iax2 show peers

Name/Username Host Mask Port Status
zp-intern/bruce 192.168.5.6 (S) 255.255.255.255 7410 UNREACHABLE
1 iax2 peers [0 online, 1 offline, 0 unmonitored]

iax2 show peers
Name/Username Host Mask Port Status
zp-intern/bruce 192.168.56.1 (S) 255.255.255.255 7410 UNREACHABLE
1 iax2 peers [0 online, 1 offline, 0 unmonitored]

nmap -p 7410 -sU -P0 192.168.56.6
PORT STATE SERVICE
7410/udp open|filtered unknown
Nmap done: 1 IP address (1 host up) scanned in 2.067 seconds

nmap -p 7410 -sU -P0 192.168.56.6
PORT STATE SERVICE
7410/udp closed unknown
Nmap done: 1 IP address (1 host up) scanned in 0.46 seconds

On freepbx webinterface I get following output (Tools -> Asterisk info)
IAX2 Peers:
Online: 0
Offline: 1
Unmonitored: 0

My sip peers are all up. Internal calling is no problem.

When I try to give a call to someone using the iax trunk (numbers starting with 90), I always get the error : all circuits are busy now - please try again later. The screen shows Service 90100 : Unavailble

These services have worked before without using the freepbx interface and config files, just asterisk.