I've been using my home internet router/modem combo for a few years and I work from home using my Polycom IP450 to call clients. I haven't had any issues.
Recently decided to upgrade it my modem to the Netgear Ac1900 c7000v2.
When I plugged in my Polycome phone, it boots up and starts as normal.
But then after a few minutes, I started getting emails from clients asking why their calls was going straight to voicemail. I was sitting right by the phone but it wasn't ringing.
So I pulled out my cell phone and called my work phone and it went straight to voicemail.
On the display everything looked normal...wasn't in DND mode or call forwarding.
So I picked the handset, like normal it gave me a dial tone...so I called my cell phone to test it...and it my cell phone rings.
Then from cell phone, I called my work phone....and funny enough it ran. So I thought everything was fine. But then after 5 minutes I started getting emails saying my phone is going to voicemail again. So once again I called from my cell phone and it went to voicemail.
So I noticed that the phone would somehow deactive from receiving calls after 5 minutes, but me making a call from it, would reactivate it somehow and it would work for 5 minutes again.
I took my Netgear back and got a new one just to assure that it wasn't a problem with the box...I even called my internet provider and had them send me a box just to test it out...and for some reason it worked perfectly with my internet provider box...
So I'm wondering if its maybe how my Netgear setting is that is making my phone deactive after 5 minutes and then reactive when I make a call..