Yealink Forums - T21P E2 Audio Issues

Hi all,

I have a very strange issue with my T21P E2 phone that is only fairly recent.

I have it connected to a PoE switch and voice QOS is a priority.

When a caller rings, I cannot hear them speak but they can hear me.

I have reset the phone to factory (I was having the reverse issue until I did this).

Handset volume is at the highest level.

When I first got the phone, this was not an issue at all.

I am at a loss as to what I may be missing and was wondering if anyone had any ideas.

Firmware Version 52.81.0.110
Hardware Version 52.0.0.0.0.0.0

wilcochris Wrote:When a caller rings, I cannot hear them speak but they can hear me.

One way audio is usually caused by the router.
Please make sure SIP ALG function of the router is disabled and the right RTP ports are forwarded/opened to the IP phone.

Hope this helps.

(06-05-2017 07:51 PM)complex1 Wrote: [ -> ]
wilcochris Wrote:When a caller rings, I cannot hear them speak but they can hear me.

One way audio is usually caused by the router.
Please make sure SIP ALG function of the router is disabled and the right RTP ports are forwarded/opened to the IP phone.

Hope this helps.

Thank you so much. This did the trick.

The bit that confuses me, is that I hadn't done this when I first got the phone and it worked.

Thank you again for your help

Glad to help - it's my pleasure and thank you for your feedback.