[asterisk-users] Freepbx VPN SIP Client (SIP/2.0 401 Unauthorized)

[basti]

Hello,
i try to connect my SIP Client (linphone) via VPN to FreePBX.
The routing looks OK. I can ping the Endpoints and traffic is routing.
I can also Register my Sip Client.

debpbx*CLI> pjsip list contacts

   Contact:  <Aor/ContactUri..............................> <Hash....> 
<Status> <RTT(ms)..>
==========================================================================================

   Contact:  731/sip:731 at 192.168.30.132:5060                163a967d99 
Avail        15.722
   Contact:  734/sip:734 at 10.8.0.143:5060                    1b1aa8cbac 
Avail        62.180

So far so good. When I try to an other extension I get a timeout.
tcpdump:

root at debpbx:/etc/asterisk# tcpdump -ni enp0s15 host 10.8.0.143 and not 
port 80
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on enp0s15, link-type EN10MB (Ethernet), capture size 262144 bytes
13:03:04.086687 IP 10.8.0.143.5060 > 192.168.30.28.5060: SIP: INVITE 
sip:731 at asterisk.kes SIP/2.0
13:03:04.087364 IP 192.168.30.28.5060 > 10.8.0.143.5060: SIP: SIP/2.0 
401 Unauthorized
13:03:04.126101 IP 10.8.0.143.5060 > 192.168.30.28.5060: SIP: ACK 
sip:731 at asterisk.kes SIP/2.0
13:03:09.054643 IP 10.8.0.143.5060 > 192.168.30.28.5060: SIP
13:03:14.112561 IP 192.168.30.28.5060 > 10.8.0.143.5060: SIP: OPTIONS 
sip:734 at 10.8.0.143:5060 SIP/2.0
13:03:14.162609 IP 10.8.0.143.5060 > 192.168.30.28.5060: SIP: SIP/2.0 200 Ok
13:03:19.057752 IP 10.8.0.143.5060 > 192.168.30.28.5060: SIP
13:03:29.060765 IP 10.8.0.143.5060 > 192.168.30.28.5060: SIP
13:03:44.672509 IP 10.8.0.143.5060 > 192.168.30.28.5060: SIP

I think the SIP/2.0 401 Unauthorized is the problem.
I also had add the VPN IP range to the local_net but that does not solve 
the problem.

root at debpbx:/etc/asterisk# grep -ri 10.8.0
sip_general_additional.conf:localnet=10.8.0.0/24
pjsip.transports.conf:local_net=10.8.0.0/24