I have 2 IPO500 V2 systems 9.1 connected together via a VPN. Both systems are Essential Edition (I know this is not supported by AVAYA but have done it a few times with no issues). I have Netgear Routers at each end. I can call site to site but sometimes you can hear each other and sometimes you can't? Anybody have any idea how I can troubleshoot this, because I obviously cant get support and I am not much of an IT guy. Any help is much appreciated thank you!