| Metric | Definition | Unit | Example | |--------|------------|------|---------| | | Time for a packet to travel to destination and back | ms | 20 ms | | Jitter | Standard deviation or mean absolute deviation of latencies across multiple packets | ms | 5 ms | | Packet Loss | Percentage of packets never acknowledged | % | 0.1% |
Where ( D(i-1,i) ) is the difference in packet transit times between packet ( i ) and packet ( i-1 ). speed test with jitter
[ J(i) = J(i-1) + \fracD(i-1,i)16 ]
Jitter is defined as the statistical variance of packet inter-arrival times. If packets are sent at perfectly regular intervals (e.g., every 10 ms) but arrive at intervals of 8 ms, 12 ms, 9 ms, 11 ms, the variation is jitter. When jitter exceeds the buffer capacity of an application, packets are either discarded or delayed, causing perceptible degradation. | Metric | Definition | Unit | Example
Tools that use multi-threaded TCP (e.g., Ookla’s default) tend to underreport jitter because parallel connections smooth out variation. Users must explicitly enable a single-threaded UDP jitter test for realistic results. 6. Case Studies: Real-World Jitter Scenarios Case 1: Wired Fiber vs. Cable vs. DSL | Connection Type | Avg Latency (ms) | Jitter (ms) | Packet Loss | VoIP MOS* | |----------------|------------------|-------------|-------------|------------| | Fiber (GPON) | 4 | 0.8 | 0.00% | 4.4 | | Cable (DOCSIS 3.1) | 15 | 9 | 0.05% | 3.7 | | DSL (VDSL2) | 25 | 12 | 0.02% | 3.5 | When jitter exceeds the buffer capacity of an