Packet loss
The share of packets that never arrive.
Definitions only — a term explained here is not a service we sell.
Packet loss is the proportion of packets sent that do not reach their destination. It can happen at a congested queue, a failing link, a radio error or a policy drop.
Why it matters
A lost packet is retransmitted or abandoned. For a bulk transfer, retransmission costs time; for a real-time stream, there is no time to retransmit, so the application hides the gap or drops quality.
Delay and loss are different failures
| Value | Zone | What it means |
|---|---|---|
| p50 | 20 ms | Typical packet |
| p95 | 60 ms | Slow tail |
| p95 − p50 | 40 ms | Variation |
Illustrative example; not a measurement of our network.
Text description
The strip cannot show loss, because a lost packet has no delay to plot. Read it as the timing of the packets that did arrive, and read loss from a separate counter over the same window.
What to check
Ask for loss in both directions, at the packet size and rate you use. A loss figure from a large probe packet may not match the loss a small real-time packet sees, and an average over a day hides a peak-hour burst. The jitter term and the throughput term cover the other measurements.