Hi, I'm building an [b]OpenVPN Server[/b] to connect from the Internet into my Home-LAN and make phone calls using [b]SIP[/b]. I've got an [b]AVM Fritzbox[/b] Home-Router from my ISP which has a build in [b]SIP-Server[/b] for Softphones. I use Softphone Software like Linphone and Jitsi. In my LAN SIP Calls work fine with no problems. But: when I connect from outside to the OpenVPN Server and trying to make calls I got issues. [list=]The connection to the [b]VPN [/b]could be established.[/list] [list=]My Softphone can actually login to the [b]SIP-Server[/b] of my fritzbox.[/list] [list=]So I try to make a call and it works. [/list] [list=]The other side received my call and when I answer it the call is established (means SIP-protocol might work fine). [/list] [list=] But!: the call has [b]NO SOUND AT ALL[/b] on both sides :( (I suggest that might be a [b]RTP [/b]problem :?: ). [/list] I used that OpenVPN Install guide: [url]https://www.cyberciti.biz/faq/ubuntu-20-04-lts-set-up-openvpn-server-in-5-minutes/[/url] Has someone any idea what can cause that rtp doesn't work? Could it be a routing issue? Or a port issue? Thanks!

VoIP Calls no Sound on both sides (Maybe RTP issue)

hans2020dieter

Hi,

I'm building an OpenVPN Server to connect from the Internet into my Home-LAN and make phone calls using SIP.
I've got an AVM Fritzbox Home-Router from my ISP which has a build in SIP-Server for Softphones.
I use Softphone Software like Linphone and Jitsi.
In my LAN SIP Calls work fine with no problems.

But: when I connect from outside to the OpenVPN Server and trying to make calls I got issues.

The connection to the VPN could be established.

My Softphone can actually login to the SIP-Server of my fritzbox.

So I try to make a call and it works.

The other side received my call and when I answer it the call is established (means SIP-protocol might work fine).

But!: the call has NO SOUND AT ALL on both sides 🙁 (I suggest that might be a RTP problem :?: ).

I used that OpenVPN Install guide: https://www.cyberciti.biz/faq/ubuntu-20-04-lts-set-up-openvpn-server-in-5-minutes/

Has someone any idea what can cause that rtp doesn't work?
Could it be a routing issue? Or a port issue?

Thanks!

hans2020dieter

OMG :o .......... The solution was so simple :lol:
Because OpenVPN routes to my Local Network I can reach fritzbox. But: fritzbox cant reach openvpn because there is no route.......
So, I went to Fritzbox Settings/Home Network/Networksettings and set a static route.
Network: (The OpenVPN-Subnet in my case 10.8.0.0)
The Netmask: (In my case 255.255.255.0)
And the Gateway: (In my case the 192.168.X.X address of my OpenVPN Server)
Thats all..... Now everything works fine!!!! 😃

Zaphod.Beeblebrox

Ohhhhhhh yes.....

So obvious that I didn´t think about it either.....

Thanks, this post saved my day!!!