If your VoIP calls sound choppy, delayed or robotic, the cause is almost always one of four measurable network metrics. Here's what each one means and what numbers actually matter.
Latency
Latency is the time it takes for your voice to travel from your phone to the other person's. Under 150ms round-trip is generally unnoticeable. Above 300ms, conversations start to feel like a bad satellite call, with people talking over each other.
Jitter
Jitter is the variation in latency between packets — some arrive fast, some slow, some out of order. Voice needs a steady stream, so jitter above 30ms causes audio to sound choppy or robotic even if average latency looks fine.
Packet loss
VoIP breaks your voice into small data packets. If packets go missing in transit — usually from network congestion — you get gaps, clicks or dropped syllables. Anything above 1% packet loss becomes audible; above 5% calls become genuinely hard to follow.
MOS score
Mean Opinion Score is the industry-standard single number combining the above into a 1–5 quality rating. 4.0+ is toll-quality (like a traditional phone line), 3.5–4.0 is acceptable for business use, and below 3.5 means users will notice and complain.
How to check your own numbers
Most business routers and firewalls have built-in diagnostics, or your VoIP provider can run a line quality test. If you're seeing problems, our guide to fixing VoIP call quality issues covers the practical troubleshooting steps — router QoS settings, wired vs wireless, and when it's an ISP problem rather than a VoIP one.
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