IP phones not connecting

Something strange is happening in my Asterisk.

I have ip phones (Yealink and Grandstream), ATA gateways (Grandstream HT701 and 703) and softhones. All extensions are NAT.

Softphones work ok between them. But when call from a softphone to an IP phone or an ATA gateway call ringing is ok but there is no audio.

What could it be happening??

“No Audio” is almost always a NAT error.

Note that by “almost” I mean that there might be one reason why other than the thousands of problems that are all NAT. You need to make sure all of the NAT settings in your phones and PBX and all of the NAT settings in your Firewall, and all of the options in your trunks, etc. are ALL set up absolutely correctly.