# problems using ssh and voip

## Gentree

Hi,

I have got a working remote desktop link to DISPLAY:0 on a remote ubuntu box and have managed to get IHU voip running on both systems and working. Now I want to try to tunnel it. 

I set local port forwarding but when I restart IHU in a different terminal it just locks up if that port is blocked on the firewall. This is then unlocked if I open the port. So clearly it is not seeing the port as forwarded via ssh.

```
localterm1# ssh -L  1794:localhost:1794 remote.dyndns.info

localterm2# ihu
```

yet from the ssh FAQ's irc example this would seem correct.

http://www.openssh.com/faq.html#2.11

[EDIT correcting link] 

What am I missing?

TIA, Gentree.   :Cool: 

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## Gentree

I don't understand this problem too much. 

vnc is working fine through ssh and I just tested the irc example above and that works too.

Is IHU not using the ports correctly that they can't be redirected ?

 :Confused: 

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## Hu

Verify that you configured IHU to use the local port forward.  You invoked it without arguments, so unless some configuration file told it to use localhost, it probably tried to go direct.

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## Gentree

 *Hu wrote:*   

> Verify that you configured IHU to use the local port forward.  You invoked it without arguments, so unless some configuration file told it to use localhost, it probably tried to go direct.

 

Do you have ANY information of how to configure it ? The only doc I can find is the man page which basically just explains the fairly obvious GUI interface.

ihu --help refers to a configuration file option but no explaination of what you may put in it or what other command line options are available. 

Much of my problem comes from a lack of proper documentation. 

What arguments can I supply to set it for local port forwarding?

If I set a secure link to forward 1794 then start IHU it says it cannot listen on that port. That must be the local port it's trying to listen on since it is not trying to connect at that stage.

Is there something I'm misunderstanding?

thx  :Cool: 

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## Gentree

Using netcat I can verify the link via ssh having blocked the port in the firewall.

```
root@remote:~# nc -l -p 1794
```

```
root@gentoo#nc localhost  1794
```

I can see what I type being echoed in both directions. 

I can set up one way ssh on this forwarding by calling localhost on gentoo end since ihu is caller and does not need to listen. But I can't do this on both ends because at least one needs to listen and it can't be set to "wait for calls" when the port is in use.

Again , if I start IHU it says the it "can't listen on TCP port 1794 (already in use?)" and I get a command line message:

```
QServerSocket: failed to bind or listen to the socket
```

Is the program trying to get exclusive usage of the socket in a way that is incompatible with ssh ??

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## Hu

 *Gentree wrote:*   

> Do you have ANY information of how to configure it ?

 No.  This thread is the first I have heard of this program.

 *Gentree wrote:*   

> Again , if I start IHU it says the it "can't listen on TCP port 1794 (already in use?)" and I get a command line message:
> 
> ```
> QServerSocket: failed to bind or listen to the socket
> ```
> ...

 Yes.  You cannot have two unrelated programs bind the same socket at the same time.

You might get this to work:

A$ ihu -listen 1794

B$ ssh -L 1795:localhost:1794 A

B$ ihu -connect 1795

I do not know if that is the right invocation, but it should show the idea.

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## Gentree

Thanks for you help. I try out that suggestion.   :Cool: 

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