[Users] Re: Problem with voice

[vallimamod abdullah]

Hi Andrew,

On 2/20/07, "Andrew Nowrot" <andrew.nowrot at gmail.com> wrote:
>
> Hi
>
> [...]
> I have two sip phones both on public IP and both registered to openser (on
> public IP). I am able to ring between this two phones (so I guess that the
> sip signalization works OK), but I can't hear any voice. For testing
> purposes I disabled the firewall on openser so I am sure that all ports are
> "free". My openser.cfg looks like this:
>

I faced a similar problem some time ago. Here are some tips based on what I
have tried to solve this:

- Capture the sip messages using ngrep: 'ngrep -qt -d eth0 -W byline port 5060'
  (of course, replace eth0 with your real iface)

- Check the sdp part to see what media IP adress is advertised by each
party ('c=IN
  IP4' line in the INVITE request and OK response.) You may have private IPs
  here if your sip phones are behind a NAT.

- Sniff udp traffic in the port range where the RTP traffic is likely to be
(I use '-s0 -X' options on tcpdump to get the payload in hex.)

- If you don't see any incoming our outgoing packet then, there ay be a
  firewall drop issue.

Hope this will help.

-- 
Regards,
-vma
.