All, I have a client we are hosting 3CX v15.5 from our Data Center. They have multiple locations with only a few phones at each (Restaurants). We have them set with a VPN connection back to our DC so all phones are provisioned over the local lan. For the most part all is good but they have periodic episodes of horrid calls. Mostly choppiness issues which I understand to be more jitter related than latency? When it happens, it is only the restaurant that can't hear the caller. The caller hears just fine. I have listened into these calls from MY remote connection and I hear both sides crystal clear. We have struggled to capture both sides of a call with WireShark when this happens as it is usually after hours and by the time we get on there to start the capture, the issue self resolves. Each site is on a Fiber connection through Comcast with PLENTY of speed. SHOULDN'T be an issue there. We have seen the issue at multiple sites at the same time and also only one at a time so it is not apparently the server or the DC network which has a Gigibit connection. I had my team add PRTG probs on that network. The issue happened again last night and was gone before I could log in but I pulled the PRTG report and saw latency cpikes up to 200ms when it is normally 20ms. I saw similar spikes in that time frame on other restaurants in that chain but NOT with other clients on different providers where we have the same probs and hosted 3CX. I am wondering if this Latency is my smoking gun but since Latency doesn't normally result in choppy or intermittent lost one way audio, I am unsure. Ideas/suggestions?