These days, latency is very low for most calls in North America. In fact, when we calculate MOS (which is a score for your call quality), we don’t even use latency if it’s under 100ms.

These days, I find more call quality issues are a result of issues on the LAN rather than the Internet. More specifically, I see voice quality degradation caused by routers/firewalls that are not quite able to deal with the volume of traffic being pushed through them.