Setup of Gamma PJSIP Trunks on FreePBX One Way Audio

Hi all I am new to FreePBX and been trying to set up my UK Gamma PJSIP to FreePBX for about two weeks now with 95% success but I am having One Way Audio. When I call into the FreePBX with my mobile phone the VoIP phone rings on answer I can hear the caller but they cant hear me. From the VoIP phone as well if I make a call from VoIP phone the mobile it rings ok but on answer I can hear them but they can’t hear me. I had a chat with support from Gamma and they did a trace on the PJSIP Trunk I do have the results of the test but not sure if I should post it here as it has a lot of information on it in regards to my service with them I am happy to PM one of the support team if needed.
But I can see in the message header it’s showing my internal IP address and not external as well in contact i have <sip:[email protected] external address when it should be something like sip:[email protected].
Gamma Trunks dont use user name and password its IP authentication so I am not sure if this could be the problem.
Please help ?

See if any of that looks familiar.

One of the sayings here is “One way audio is almost always a NAT issue.”

That’s a NAT error in action. Sounds like you answered your own question.

Hi Cynjut thank you for reply how can I fix this problem? should I just turn off Nat I am using apple airport extreme as the router

There are at least three places where the NAT setting has to be correct, and your router is only the first.

The second is your PBX SIP Connection.

The third is your extension settings.

They all need to be right to fix your problem. Are you having trouble reading the Wiki?

Hi Cynjut I have troll over so many support post and yes Wiki there’s so many similar problems with a different solution hard to tell whats the right fix for my problem hence why I posted this? I am sure these settings or correct but will double check it do you think this is why I am getting one-way audio.

I’m not sure what else you need me to do. You have to set the NAT settings right in these three places. I can’t tell you which is causing the problem, because any of them could cause the problems you are seeing.

I know and thank you for your help it’s much appreciated I will go over what you mentioned once back in the office tomorrow and post any updates

one more thing how would I change message header
sip:[email protected] external address
sip:[email protected] external address

If you get stuck open a ticket with us we’d be happy to review it

The advice given thus far is good - you didn’t mention the firewall make and model , I would typically start with a google search of it specifically and get more general adding “sip problem” to the search string

Ie - “sonicwall tz210 sip problem”

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