we use GXV3370. Our ISP installed a new router. Now we have the problem that people who call us cannot hear us, although we can hear them. When we are calling outbound there is no problem both ways, only if someone calls us.
ISP tells us, he was never supporting Grandstream telephones for his routers, so it’s our problem - they cannot do anything for us. Welcome to Germany
We updated the firmware (both router and telephones). We also looked in this forum for some ideas, but everything seems to be correct. As Codec we use PCMA/PCMU because these are the codecs our provider (Deutsche Telekom) uses. NAT is also at “keep alive”.
Is there anybody who has an idea what we could do inside phone or router configuration to solve this problem?
Thanks a lot!