Extension behind a VPN

[tobiastromm]

Hi.

I have a VPN and when the VPN connection is maked from the computer the extension work's fine.

I buy a router and install the DD-WRT firmware, that's provide me a VPN connection.

I can access my files, my server, so the VPN is working.

The extension register in the PBX server, but when I make some call there is no audio.

What can I do?

 

[tobiastromm]

 

[garyjduk]

I take it that you are using the 3CX softphone on the computer that is connecting using a PPTP VPN 'dial up ' connection?

Try using the tunnel through port 5090 it will probably be easier.

 

[tobiastromm]

Hey...

When I connect VPN with Windows dial up connection, the VoIP work.

When I connect VPN with the router, all works (vpn is working) but there is no audio.

I don't wanna use the tunnel, can I do something?

 

[leejor]

Are you using two DD-WRT firmware routers? One at each end? On your post you show the PPTP server disabled. If you are only using one router, at the 3CX end, it would be the server, and the PC would be the client. If you are setting up a DD-WRT router to connect with with a PPTP server at the far end , then there may be some settings in that router (at the 3CX end) that need tweaking. Is there audio in one direction? Have you done any port forwarding on the router at the remote end? Haven't looked into it in depth but I'm assuming that VPN sends everything through one port, in a similar way the 3CX tunnel option works. So it is a matter of the VPN routers sorting out all of the "real" ports correctly at each end.

I use a DD-WRT based router and have had no issues using either PPTP VPN or tunnel, from a PC, with the 3CX phone.

 

[tobiastromm]

Leejor,

the router is the vpn client. The PPTP server is Windows 2003 server.

If you are setting up a DD-WRT router to connect with with a PPTP server at the far end , then there may be some settings in that router (at the 3CX end) that need tweaking.

What i need to change?

 

[leejor]

Haven't used the Windows VPN server. I don't know if there is a compatibility issue or not. If your other data is passing through correctly then it is probably a matter of sorting out the audio ports at each end. Do you get audio one way?

Think about it this way...at the 3CX end, you have port forwarding to tell the router...send these ports to the IP for a PC running 3CX (or you would if it is running on a separate PC). at the remote end, you may need to do the same thing. The DD-WRT router may need to be told to send the audio packets to the IP of the PC running 3CX phone. It generally necessary to do port forwarding at a remote end router, but, using VPN may cause things to work a bit differently. Play around with the port forwarding in the DD-WRT router.

 

[tobiastromm]

Leejor,

I make the test now.

Call another extension and the "extension" can hear me but i can't hear the "extension".

 

[leejor]

As I said, it sound like a port forwarding issue at the remote router.

 

[tobiastromm]

What ports and protocol I need to port forwarding?

 

[leejor]

I would start with a wide range of ports (all?) and then if you were able to pass audio,then begin to narrow that down. I would think that they may centre around the 9000 to 10000 ish area

 

[tobiastromm]

Leejor,



If you have a little time can you access my router and do this?

Has you MSN?

We post the result.

I now i'm a free user...

 

[leejor]

Sorry, I don't do MSN, and I'm on my way out the door right now. Just tinker with the port forward options. It may just be trial and error, or it could be a setting that needs to be changed so that the router knows where to send the ports on it's own.

 

[tobiastromm]

I make this rule:



But still there a only way audio.

Do I correct?

 

[leejor]

Yup, that's what I would have tried first. You may have to resort to using Wireshark on either side of the VPN to see what might be going on, unless, someone else is familiar with your particular set-up. Others have used a VPN router to set up a secure connection and run both data and 3Cx phones over it in the past, so it is possible. There may just be something that you are missing.

 

[tobiastromm]

Leejor,

on my first image there is a NAT and it is Enabled.

I read about that and people say that is it cause the problem.

But, if i disable NAT the VPN connect but no data traffic is send.

Can i do something about?

 

[tobiastromm]

Leejor,

I make the wireshark capture.

The file has 2 MB.

"The file is too big, maximum allowed size is 256 KiB." (i zip it)

How can I send it?

PS: when I receive a call there is 2 way audio. The problem is only when I make the call...

 

[tobiastromm]

Hi.

I upload the wireshark capture to:

http://www.4shared.com/file/0VJH8DOx/wireshark_capture.html

Thank You.

 

[tobiastromm]

Nobody?

 

[abc123]

We could not get the file - the site didnt allow me to download or was non responsive.

PM me and we can see about emailing it direct.