Yealink Forums

Hi,

I have to connect T42/T46 phones over OpenVPN for our Switchboard and Helpdesk. The VPN Connection works fine, but the phones are not able to register on the SIP Server when using SIP on UDP. SIP on TCP works fine, but is not compliant to our Call-center.

Any Idea why SIP is not registering on UDP? I tried many options on the VPN server, without any results (OpenVPN over UDP and over TCP, OpenVPN Clients can join the other clients or not, all clients in one /24 subnet, or every client in a /30 subnet...)

Here 2 vpn.cfg, with both configurations, SIP is only registering when on TCP. I also tried to play with the send/receive Buffer, which didn't help...

Initial configuration (working fine with SIP/TCP, no register on UDP, tested over UDP and TCP):

dev tun
persist-tun
persist-key
cipher AES-128-CBC
auth SHA256
tls-client
client
resolv-retry infinite
remote sub.mydomain.ch 1194 udp
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
remote-cert-tls server

My last configuration, also tested over UDP an TCP, in TUN and TAP mode (no one is working with SIP/UDP):

dev tap
persist-tun
persist-key
cipher AES-128-CBC
auth SHA256
tls-client
client
resolv-retry infinite
remote sub.mydomain.ch 1195 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
remote-cert-tls server
nobind
route-delay 2
redirect-gateway
passtos


Do you have any Idee why the phones doesn't register over UDP? Thanks

PS: We are using Firmware version 66.81.0.110