FreePBX 17 and grandstream phones with OpenVPN

Commercial Modules
1

I now have systemadmin openvpn and grandstream GXP1610 phone but have no clue how to set it up. Is there really a way to set it up since I’ve been searching and trying but it wouldn’t work.

Here’s my sysadmin_server1.conf:

# Configuration automatically generated via Sysadmin RPM
# MODIFICATIONS TO THIS FILE WILL BE OVERWRITTEN.
# Generated at: Mon, 22 Dec 2025 14:31:18 +0000
log /var/log/openvpn.log
port 1194
proto udp
dev tun
topology subnet
ca sysadmin_ca.crt
dh sysadmin_dh.pem
crl-verify sysadmin_crl.pem
cert sysadmin_server1.crt
key sysadmin_server1.key
ifconfig-pool-persist ipp.txt
keepalive 10 120
comp-lzo
persist-key
persist-tun
verb 3
client-config-dir ccd
ccd-exclusive
status sysadmin_server1-status.log 10
status-version 3
script-security 2
reneg-sec 3600
server 10.8.0.0 255.255.255.0
push "redirect-gateway def1 bypass-dhcp"

and my sysadmin_client1.conf:

# Configuration automatically generated via Sysadmin RPM
# MODIFICATIONS TO THIS FILE WILL BE OVERWRITTEN.
# Generated at: Mon, 22 Dec 2025 16:35:09 +0000
client
dev tun
proto udp
resolv-retry 60
nobind
persist-key
persist-tun
remote-cert-tls server
ca sysadmin_ca.crt
cert sysadmin_client1.crt
key sysadmin_client1.key
comp-lzo
verb 3
reneg-sec 3600
remote (my dynamic domain provided by FreePBX)1194
remote (my dns server) 1194

My OpenVPN server settings tab currently have no routes (?)

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image1347×777 30.8 KB

I have setup the clients:

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image1335×486 21.6 KB

I would really appreciate the help!

2

FreePBX with Grandstream over OpenVPN can work, but setup takes patience. I remember chasing audio issues and registration drops until tunnel settings matched on both sides. Once keys, routes, and NAT options were clean, phones stayed solid. I prefer keeping VPN simple and testing one device first before rolling out more. Small tweaks saved hours later.