Good morning,
I would like to point out that this is the first time I manage VoIP phones, even though I already have experience in configuring port forwarding. I will briefly summarize the situation and the problem encountered:
*I installed a Fritz!Box 5960 Pro as the main router.
*I correctly configured a FreePBX server in the local network.
*I opened ports 5060 UDP and 10000-20000 UDP in the server firewall.
*In the local network, the Zoiper app connects perfectly: I can receive and make calls without problems.
The problem arises when we try to use Zoiper remotely (out of the office):
we would like to be able to make and receive calls from mobile phones when we are out of the office.
For this reason I tried the following configuration:
*I set the FreePBX server in DMZ temporarily, to exclude problems related to port forwarding (the Fritz!Box only allows the opening of WAN ports one at a time).
*In FreePBX, under Asterisk SIP Settings, I have already correctly configured the public IP and the local network.
*In Zoiper, I have entered the public IP in the various configuration fields, except in the “gateway” field, where:
**If I leave it empty or set the public IP, the registration fails.
**It only works by setting the local IP, which obviously is not possible remotely.
At the moment we do not want to configure a client-to-site VPN, due to technical and management limitations.
I kindly ask for support to understand:
*If I am leaving out some important configuration in FreePBX or in the router.
*If there is a correct way to allow Zoiper to register and work remotely, without using VPN.
*If it is necessary to do further NAT/SIP ALG configurations or changes to the SIP parameters (eg. NAT, External Address, etc.).
I also want to add that I saw from the log that I was wrong, the connection comes from portforwarding, only it is not established
Thanks in advance for the support.
I remain available to provide further details or configuration files, if necessary.