My client is using 8x8 Voip phones, which I have used for a number of years without a problem. They have Comcast internet service (not sure of the speed), a Meraki MX60 firewall. Their calls frequently have static and often get dropped entirely. Comcast has replaced their modem; 8x8 has done ping testing which shows normal one day, then latencies in the 400ms range the next. Computers seem to function fine. Questions:
1. What tests can I run to identify where the problem lies?
2. If you've seen this before, how did you resolve it?
3. Should Comcast be able to identify the latency source?
Any other ideas?