Dropped Call and Echoing Help Please!

I'm having an issue with calls dropping. I'll be on the phone, hear a click, about a second later I get the dial tone. This doesn't happen on every call but it is happening about 50% of the time. Occasionally we are getting echoing as well where we can hear ourselves talking or the person we are speaking to can hear themselves. I can confirm that it's not the phones as I have POTS service as well and the phones work fine with it. I have made multiple patch cables and bought a few as well with no luck in fixing this issue. We use this in my home office so it's becoming a real problem.

I have a Grandstream HT502 adapter connected to a TP-Link R470T+ Multi-WAN router. It's been assigned a static IP, port range 5004-65000 UDP has been forwarded, SIP ALG has been turned off. I have a multi-wan setup so I was able to test this over different ISPs. The adapter however is not part of my load balancing setup and is set to use only 1 ISP. I have also provisioned the port the adapter is using to have a full 512kbps upload and 1024kbps download minimum at all times.

Any help is greatly appreciated!

I would definitely open up a support ticket. Dropped calls and echoing issues are not typically caused by the end users network setup. Since you've tried the ATA on different ISP's with the same result, this tends to point to an ATA problem or carrier issue. In either case, Voipo is responsible for both. I would log into vPanel and go to the Call History log, and try to gather as many of the call reference numbers associated with these dropped / echoed calls. I would paste these call reference logs into the email support ticket for their analysis. It will help them determine whether it's being caused by the ATA or a carrier, or possibly both......