Remote Extension Internal Call no Audio

[bozway]

Hi all, I have a strange problem with my system 11 3CX server.

I have an Godaddy VPS and install the server on there, so all my extensions are remote extension, the phone call works well if call was placed from any where outside. But If I make a extension to extension internal call. Call will ring but no audio after I picked up the phone call.

I tried to use Both 3cx phone on IOS, Android, windows, and regular cisco phone as remote extension, but none of them works. I also found an even stranger situation is when I use the mobile 3cx, if I hit the "record" button while I'm still on the line with another internal extension, then audio works. I also tried to go to Management console and in extension configuration, selected record all phone calls on the extension, then the internal call works.

My guess is, when I make it record the call, the audio traffic would forced to go through the server. Another wise, between extension to extension, audio only delivered without the server. That's probably why internal call wasn't working.

If so, what should I do to make local phone calls working? It must a server config issue right? Otherwise at least two mobile remote extension would work just fine, since it has nothing to do with the CISCO phones.

Please help.


Thank you.

 

[mlump]

bozway,

I assume you have the extensions setup as remote extensions using STUN, you will need to check PBX delivers audio for every extension. You should be able to find this under the extension settings on the other tab, it should be the top check-box. If for bandwidth issues having the 3CX server proxy the audio for internal calls is not acceptable, you need a firewall capable of hairpin NAT and to setup a NAT rule for each phone, another option would be to use the SIP Proxy Manager.

Mike Lump
3CX Advanced Certificated
ComResource Inc.

 

[bozway]

Hi, thank you very much for your help.
After I check PBX delivers audio, it works, but with delay, I guess it's probably the bandwith issue.

I saw that you suggested "you need a firewall capable of hairpin NAT and to setup a NAT rule for each phone", how exactly could I do to en able that? Any articles talk about that? I want to try that method, it will help me reduce server load as well.

Thank you for your help again.

 

[mlump]

Hi, thank you very much for your help.
I saw that you suggested "you need a firewall capable of hairpin NAT and to setup a NAT rule for each phone", how exactly could I do to en able that? Any articles talk about that? I want to try that method, it will help me reduce server load as well.

Thank you for your help again.

Setup would depend on the type of router you have and if its capable of it. I may be able to help, what router do you have?

 

[bozway]

I have a regular home based router RT-AC66R..

What kind of configuration would I need to do on the router?
I probably could find related configuring article myself as well.

Thanks!

 

[mlump]

Hairpin NAT would be setting up a NAT rule per phone to point the traffic coming from the inside to the routers public IP to specific phones based on the port that is used(Phones would need static IP addresses and unique RTP ports). I'm not sure a home router will support it. Without a router purchase you may want to look at the 3cx proxy manager.

 

[leejor]

How many sets are you using at the remote location?

For more than a couple, the 3CX proxy server is the best way to go. It sounds as 3CX has come up with an alternative using the Raspberry Pi, although, at the moment, I'm not sure the intention is to be a drop-in replacement for the Proxy server.

http://www.3cx.com/forums/3cx-sbc-raspberry-pi-38898.html

Another alternative, depending on how much effort you want to put into this, is a router running the DD-WRT VoIP firmware. It has, what appears to be a proxy server built in, and might be worth investigating. I'm not sure how well it would handle call recording when audio has to be routed back through the PBX. There are some older routers (I'm thinking Linksys WRT54G, certain versions) capable of running this, that can be found at thrift stores for a few dollars. It might be worth considering, but do your research. If you can find a suitable router, cheap, then even if it doesn't work properly, you are only out-of-pocket a few dollars.

 

[ian.watts]

Many routers have a SIP ALG component.. in the past I hated.. but for about a year it has worked just fine on my ActionTec with a handset registered to three different systems and a softphone here and there without tunnels, all work fine with it at the same time.

They register to whatever host(s) they do, and I do "not" enable any of the RPORT/NAT-T options anywhere. Works fine.

Mileage varies as always.