One Way Audio or No Audio on Remote Extension

“Hello? Hey? Can you hear me?”
“Yes, I can hear you. But I think it's you who can't hear me!”

I bet this conversation happens many times when you work from home recently or work remotely with your remote extension. You may say it's no sound or me-lost-you-again. We call it One Way Audio or No Audio technically. Most people would still blame bad signals or network connection. Hanging up the phone and then making another call instantly works but it is not the correct way to fix the problem. So in this video, I show 4 methods to figure out what caused 1-way audio or no audio from the PBX side.

Generally, there are 4 common causes for the issue:
1. Incorrect SIP NAT settings on the PBX 00:45
2. Incorrect ALG settings on the router 03:37
3. Incorrect Extension NAT settings on the PBX 04:11
4. Incorrect RTP port forwarding settings on the router 04:51

If these four remedies still can’t solve your problem, visit and contact our technical support team by submitting a ticket or starting an online chat.

Here are some related online documents you are looking for:
How to Configure PBX NAT Settings: https
Understand the PBX NAT Settings: 
The Router Settings Relevant with One-Way Audio Issue: 
RTP Port Forwarding Reference: 

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  • 0
    These also server guidelines for the Yeastar P-Series Cloud Edition platform?
    Is there a video or article about these occurrences on the P-Series Cloud?


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