T21P E2 OpenVPN Disconnects

[acca]

Hello Everyone,

My OpenVPN-server side is based on the pfSense OpenVPN router. I've configured the tunnel for SIP clients, and I have two older T20P phones which are using the tunnel, and work flawlessly.

I've got two T21P E2 phones, which are configured using the same vpn.conf file and different certificates. Initially, everything works fine. Phone will connect to the OpenVPN server, and asterisk. After the period of inactivity (approximately 2-5 minutes), T21P drops the VPN connection, and becomes unreachable. T20P is working all the time.

On the VPN server side, I see the timeout message, and failure to communicate to the T21P. After rebooting the phone it works for few minutes, and fails again.

I've tried to modify the T20's client configuration file to use it with T21. Currently it looks as follows:

dev tun
setenv SERVER_POLL_TIMEOUT 4
persist-tun
persist-key
cipher AES-128-CBC
auth SHA1
tls-client
client
#resolv-retry infinite
nobind
reneg-sec 604800
sndbuf 100000
rcvbuf 10000
auth-retry nointeract
remote server.ip.address 1197 tcp
ca /config/openvpn/keys/ca.crt
cert /config/openvpn/keys/client1.crt
key /config/openvpn/keys/client1.key
tls-auth /config/openvpn/keys/ta.key 1
ns-cert-type server
comp-lzo no
verb 3
passtos

Do you have any suggestion? I've been checking the phone's logs, but couldn't find anything OpenVPN related. When phone drops the tunnel, I have to disable VPN manually and device will reboot. Logs are empty after reboot.

Best Regards,

Aleksandar