We have several NEC IP Phones and a few Grandstream ATA Adapters for fax machines and analog devices. Before a recent firmware upgrade to 8.00.00, everything was good. After the upgrade, a few of the Grandstream devices have been having issues. The first one seemed to be resolved by re-assigning a different IP address to the device. I spent half a day troubleshooting, swapping extensions, replacing the adapter with a new one, checking for IP conflicts, etc. Of course, the last thing I tried was changing the IP address and it started working and has been solid since.
However, this other Grandstream ATA that goes to a DoorKing gate phone. Before the upgrade it was fine. After the upgrade, anytime it dialed a NEC VoIP, it the NEC VoIP would ring, but the ATA would received a busy signal. When the NEC VoIP went off-hook, it would hang up and drop the call. Using the Grandstream ATA, I can tell the DoorKing to dial a SLT/MLT, an off-prem phone or even a cell and it works. But since the upgrade, that one adapter will not work when dialing a VoIP phone.
I remember from class a few years ago, an article ID 11373 - VoIP Terminals Receive Busy Then Hang Up When Going Off Hook to Make or Answer Calls (Published in 2014). It talked about licensing in 10-54-01, but that's not my issue. I've got license for 150 IP phones. I'm really thinking this has something to do with the firmware upgrade. We've replaced the ATA, moved extensions, changed IPs, replaced the DKS dialer, etc...nothing seems to work. Suggestions?
