openvpn tunneling udp to connect ekiga bypass blocked ports

Maxei

Hello,

My question is:
can openvpn forward UDP through a non-blocked port, so that Ekiga client could connect to the ekiga server or the STUN server?
If yes, can you please suggest some start points, as I am totally new in this.

What is my problem?
My university has recently blocked ports that are used for VOIP applications; now Ekiga and Skype cannot connect at all (either Windows or Linux PCs, confirmed).
Apparently, all ports with UDP protocol are not listening (hence blocked); but some TCP ports are listening:

Here is to show that the port 3478 used for stunt is blocked:

$ekiga -d 4 2>&1 | grep STUN
2014/09/23 14:28:01.865	  0:08.334	StunDetector:0xb727db70	STUN	No response to STUN server 77.72.174.161:3478
2014/09/23 14:28:01.865	  0:08.334	StunDetector:0xb727db70	OPAL	STUN server "stun.ekiga.net" replies Blocked, external IP 127.0.0.1
2014/09/23 14:28:01.866	  0:08.334	                       	STUN	No response to STUN server 77.72.174.161:3478
2014/09/23 14:28:05.385	  0:11.854	  subscriber:0xb727db70	STUN	STUN server 77.72.174.161:3478 unexpectedly went offline.

I can confirm which ports are listening and which are not (because the university server is blocking them; my firewall is not the problem):

$sudo netstat -tulpn
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address           Foreign Address         State       PID/Program name
tcp        0      0 127.0.0.1:631           0.0.0.0:*               LISTEN      1321/cupsd      
tcp        0      0 0.0.0.0:1720            0.0.0.0:*               LISTEN      2694/ekiga      
tcp        0      0 127.0.0.1:38096         0.0.0.0:*               LISTEN      2617/beam.smp   
tcp6       0      0 ::1:631                 :::*                    LISTEN      1321/cupsd      
udp        0      0 0.0.0.0:48434           0.0.0.0:*                           913/avahi-daemon: r
udp        0      0 10.135.21.92:5060       0.0.0.0:*                           2694/ekiga      
udp        0      0 0.0.0.0:68              0.0.0.0:*                           1520/dhclient   
udp        0      0 0.0.0.0:5353            0.0.0.0:*                           913/avahi-daemon:

The above result indicates that TCP ports are not blocked (status LISTEN; all UDP ports are blocked (status is not LISTEN).

Ekiga uses ports 5000 to 5100 for SIP signalling (UDP); Ports 3478 to 3479 for outgoing to STUN (UDP); Port 1720 is used as listening port for TCP (H323).

Thanks.
Maxei DeVraie

Traffic

Maxei wroteThe above result indicates that TCP ports are not blocked (status LISTEN; all UDP ports are blocked (status is not LISTEN).

That is not what it shows.

TCP Ports which are listening are doing so on the computer you are sitting at,
that does not mean they are not blocked over the network.
UDP Ports do not have a status as UDP is a connectionless protocol,
this also has no bearing on whether the network is blocking those ports.

Maxei wroteMy question is:
can openvpn forward UDP through a non-blocked port, so that Ekiga client could connect to the ekiga server or the STUN server?

OpenVPN can do this provided you have an administrator/root account to install OpenVPN and manage the routing table ..

Maxei wroteIf yes, can you please suggest some start points, as I am totally new in this.

Start here:
OpenVPN Community Edition Documentation

Maxei

Thanks Traffic for your reply. I still have a doubt on your comment:

That is not what it shows.

TCP Ports which are listening are doing so on the computer you are sitting at,
that does not mean they are not blocked over the network.
UDP Ports do not have a status as UDP is a connectionless protocol,
this also has no bearing on whether the network is blocking those ports.

Accordingly, if the UDP ports 'were not' blocked, as you seem to say (not sure though), how come I cannot connect? AFAIK, the university has blocked the voip apps. Can you please explain a bit more? since UDP is a protocol that uses ports, hence, if that port is blocked by the university firewall, the result is no connection. Right? If not, how is the blocking happening? Am I missing something?

As for your answer to my question, (which is very easy: yes or nope), thanks; thanks also for pointing to the documentation.

Maxei

My question is:
can openvpn forward UDP through a non-blocked port, so that Ekiga client could connect to the ekiga server or the STUN server?

OpenVPN can do this provided you have an administrator/root account to install OpenVPN and manage the routing table ..

sorry, I forgot to ask you about your answer: "provided you have admin/root account": do you mean the Open VPN offer option "Admin. Web Interface/Admin UI", which I have to pay for? or, do you mean if I have admin/root access to my university's server? if it is for this second possibility, obviously I don't have.

Thanks.

Maxei De Vraie

Traffic

Maxei wrotehow is the blocking happening? Am I missing something?

Yes .. you are missing something.

You have run netstat on a local machine and you now have a list of ports in use by processes on that machine,
you have not tested across the network which ports are blocked or not.

Maxei wroteprovided you have admin/root account": do you mean the Open VPN offer option "Admin. Web Interface/Admin UI", which I have to pay for? or, do you mean if I have admin/root access to my university's server

You require root access to the machine you intend to install OpenVPN on .. which version of OpenVPN makes no difference.

It is very unlikely, with your current knowledge of your OS/Networking and VPNs, that you will be able to defeat the university network security.

I suggest you ask for permission instead.

Maxei

You require root access to the machine you intend to install OpenVPN on .. which version of OpenVPN makes no difference.

Oh Boy! wasn't it clear enough from my original post when I typed: "$sudo netstat -tulpn" ???? Read carefully, I would say; then you should have not even said a word about this. You just wrote pure noise; nothing of help.

It is very unlikely, with your current knowledge of your OS/Networking and VPNs, that you will be able to defeat the university network security.

really??? what an arrogant piece of rubish you wrote. In the end, you should have abstained from replying, Mr. arrogant; who gave you permission in this forum to look down to people who asks for help???
I Have got nothing but useless arrogant rubish from you, a newbie; if at least you have had helped in this forum a dozen people with USEFUL information, but I DOUBT it; just pure noise you write. Please abstain from this thread.

Maxei De Vraie.

Traffic

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