[afnog] CONNECTING TWO PBX OVER THE ASA FIREWALL

[Sicelo]

On Mon, Jan 28, 2019 at 10:47:43AM +0200, David Chima wrote:
> Dear AfNOG
> I need help. I have an ASA 5506-X running software version 9.5(2). I have
> connected one PBX on the SERVER DMZ and the other PBX is in the WAN 300Km
> away.
> I have setup the firewall with static NAT so that the IP addresses are not
> seen on either side as dynamically assigned but statically as they are. I
> have also setup inspection for SIP and H323.
> 
> The PBX can talk to each other somehow because from an extension attached
> to one PBX I can call the other extension on another PBX, but the call
> recipient cant hear anything after lifting the receiver.
> 
> Anyone who can help me please
> 
> Regards
> 
> David Chima

While I do not know anything about your devices and pbx models, I do
know that the 'problem' with SIP is that the media (the audio) opens its
own channel, separate from the control channel. The control channel is
working in your case, hence you are able to place a call, but the media
channel fails. You may be able to configure your pbx to send the media
through the already established channel instead of trying to establish a
new one.

Of course, I hope that someone will give you even more specific info.

Best wishes
Sicelo