Hi everyone.
We have an Asterisk on a PC with two NIC. NIC1 has GW and internet (Behind NAT), and NIC2 has an IP address just for SIP trunk2 (Routed address). I added the static routes to SIP provider 2 via NIC2 and my SIP trunks is registered successfully. My SIP trunk 1 is working fine also. But when I call my SIP trunk 2 number by my phone, I can not hear the IVR voice and call drops after 6 seconds. I took a look at asterisk -r debug and I found that there is an error about SIP Retransmissions timeout. When I change my Asterisk SIP advanced settings from Static IP to Public IP, SIP trunk 2 works fine, but SIP trunk 1 has no inbound calls from out.
These are my SIP trunks settings:
SIP 1 (Behind NAT on NIC1):
type=peer
host=X.X.X.X
nat=yes
fromuser=ZZZZZZZZZZ
username=ZZZZZZZZZZ
secret=YYYYYYYYYY
context=from-trunk
qualify=yes
insecure=port,invite
canreinvite=no
disallow=all
allow=ulaw&alaw
registerattempts=0
registertimeout=20
t38pt_udptl=yes,redundancy,maxdatagram=400
faxdetect=yes
SIP trunk 2 (Routed via NIC2):
host=U.U.U.U
type=peer
qualify=yes
canreinvite=no
context=from-trunk