I have 3 VPN site connect to One system . Only the site was first one connected to system - VPN A, it was working , Other two site phones were fail to register.
Because I made another test : When these VPN sites register another system 192.168.0.x , VPN B is working and others VPN site not work !
Therefore , I confirm that those VPN sites setup were OK and those IP phones setup are correct !
System = 192.168.0.x /24
VPN A = 172.27.2.x/24
VPN B = 172.27.4.x/24
VPN C = 172.27.6.x/24
I entered the data in the sip_general_additional.conf file:
Yes ! three VPN sites phones can ping the system , can web access the admin page of the system .
I found out the problem came from : The system only allow one VPN site register !
Because 3 VPN site : A , B , C . Result was that only one VPN site can register !This case is VPN A for System “192.168.0.100”
Then I made another test to register second system! Same VPN site : A , B , C . Result also was that only one VPN site can register . This case is VPN B for System “192.168.0.200”