Asterisk - IAX2 не работает без перезагрузки

server1*CLI> iax2 show peers
Name/Username    Host                 Mask             Port          Status      Description                     
server2     192.168.0.1     (S)  255.255.255.255  4569 (T)      UNREACHABLE                                 

root@server2:~# tcpdump -i tap4
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on tap4, link-type EN10MB (Ethernet), capture size 65535 bytes
09:56:45.368311 IP 10.1.0.190.iax > 192.168.0.1.iax: UDP, length 14
09:56:45.368409 IP 192.168.0.1.iax > 10.1.0.190.iax: UDP, length 12
09:56:46.369913 IP 10.1.0.190.iax > 192.168.0.1.iax: UDP, length 14
09:56:46.370007 IP 192.168.0.1.iax > 10.1.0.190.iax: UDP, length 12

server1*CLI> module unload chan_iax2.so 
Unloaded chan_iax2.so
server1*CLI> module load chan_iax2.so 
Loaded chan_iax2.so
server1*CLI> iax2 show peers
Name/Username    Host                 Mask             Port          Status      Description                     
server2            192.168.0.1     (S)  255.255.255.255  4569 (T)      OK (5 ms)