12.5 sp1 Remote Audio not working

[AndyBarr]

Hi Guys,

Just trying to sort out a Demo for the MD so we can look to purchase in the next few days and I have hit a snag - it seems that we have no audio coming from remote extensions. This was working last week, but something has changed (but nothing we have done intentionally, no windows update or the like)

Internal Calls are fine, but any calls to remote extensions don't seem to work.

Firewall checker has come back all green and ok
Softphone and remote phones are registering fine
Have tried with both pbx delivers audio on and off
The MD could hear me when he made a remote call (remote snom 300 connecting directly to external IP) but I could not hear him.
external softphone to internal softphone - no audio either way

I have updated to sp1 this morning to see if that has made any difference, but still no joy.

Looking at wireshark it seems that the connections are ok, but I might be missing something.

I can provide logs if need be

 

[AndyBarr]

Just for more info,

If I set the pbx to record all audio for an internal test extension and the remote extension, it creates a recording of the audio for dialing each way and both sides of the conversation can be heard.

This is with pbx delivery audio on and off.

 

[leejor]

Well...if the audio is being recorded, from the remote extension, then it would appear to be "getting through" to the PBX but not being passed to the local extension. Don't recall that particular scenario coming up before. In most cases, no audio, is the result of a fire wall/router/issue/misconfiguration.

How are the remote extensions set up? Are there a number behind one router? Is the 3CX SBC being used?
Have you tried a remote extension from a different location? If that also had an problem it would pretty much confirm that the issue was local, which I already suspect.

What male/model router/firewall are you using locally, that could be playing a part here. Since it did work at one point, have you tried re-booting the router? Do you have a second router, with just the basic port forwarding implemented, to test with? Have you tried eliminating all else on the local network, i.e. plug the 3CX server and one set, directly into the router, then have a remote extension place a call.

 

[AndyBarr]

Thanks for the reply

I am thinking firewall but a bit unsure.

What I have been trying this afternoon....

The remote extension is a direct connection (Static IP address NAT'd to 3CX server)

We have tried it from a snom 320 at MD house - phone registers and he can hear me at the other end, I just couldn't hear him, not too sure what router he has.

I have tried plugging in a windows soft client in to our guest connection (straight internet connection) and that registers but no audio at either end.

We have also tried a 3cx android client on a 4G connection (o2) - no audio at either end

I have tried using tunnel, but I cant seem to get the remote extensions to register this way.

I have tried making a connection via startrinity sip tester and the call is made (internal extension rings and I can pick up) but if when I drop the call from the internal handset it doesn't drop the call at the SIP testers end.

Thanks

Andy

 

[leejor]

I have tried using tunnel, but I cant seem to get the remote extensions to register this way.

This may be indicative of a larger issue (and you are obviously experiencing that), if the correct port (5090) is forwarded. Is there a sign of the tunnel attempting to connect, in the 3CX server log?

You still haven't made mention of the router/firewall in use at the 3CX end. Someone else may have had experience with that unit and may have some advice on what settings may have to be changed.

 

[AndyBarr]

The firewall at the 3CX end is a Linux iptables server connecting to a lease line.

All ports required forwarded to the 3cx server.

could it be that the inbound IP address (public IP) be different to the outbound IP?

I will check the logs on the tunnels tomorrow morning.

Thanks

Andy

 

[leejor]

could it be that the inbound IP address (public IP) be different to the outbound IP?

Inbound IP, meaning the static IP you have been assigned by your ISP, and outbound IP being ...what?, the IP of the extension? That IP would be determined by the registration information sent to 3CX by the device. This is usually in the form of the public IP of the router at the remote end 9that the extension is behind) along with the port assigned to that particular extension.

Yes, those two would be different.

 

[AndyBarr]

Sorry,

We have 14 usable statics, with the inbound IP address not being the first one, but the outbound IP address will probably be set to first static in the range, could this make a difference.

Thanks

Andy

 

[leejor]

We have 14 usable statics, with the inbound IP address not being the first one, but the outbound IP address will probably be set to first static in the range, could this make a difference.

It may, depending on your set-up. I would certainly think that it could complicate things if ports are not forwarded properly.

As I said previously, the fact that 3CX is recording both sides of the conversations would suggest that audio is making its way through, at least to the PBX. I'm at a loss, given that information, as to why it isn't making it to the extensions.

Are you able to move the current server, on which 3CX resides, to another location, at least one behind a different router/firewall. Perhaps one with a single public IP. I suspect that substituting various hardware components, of your current configuration, until the problem is solved, may be your only route.

Short of that, you'd have to hope that another forum member has had experience with a Linux iptables server and can provide some suggestions.

Perhaps the use of Wireshark, at various "points" in the "chain" can provide some direction.

 

[AndyBarr]

Thanks for the pointers, and I will be brushing up on my wireshark knowledge ASAP!

I am also building the final solution server at the moment, so we can test against that as well.

The real bugbear was that it was working absolutely fine, and there could also be the possibility of something at the MD's House.

I am getting the phone back tomorrow and will do some local testing (we have a separate ADSL for guest wifi) so I can see it works with that.

If I find a solution I will post it up here, to help future enquiries

Thanks

Andy