[ J(i) = J(i-1) + \fracD(i-1,i)16 ]
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 | speed test with jitter
| Application | Max Tolerable Jitter | Typical Buffer | Consequence of Excess Jitter | |-------------|----------------------|----------------|-------------------------------| | VoIP (G.711) | 20 ms | 30–50 ms | Choppy audio, clipped words | | Video conferencing (Zoom) | 30 ms | 80 ms | Frozen frames, audio desync | | Online gaming (FPS) | 15 ms | None (real-time) | Rubber-banding, missed shots | | Web browsing | 200 ms | Large (HTTP cache) | Negligible | | 4K streaming | 50 ms | 2–5 seconds | No effect (buffered) | [ J(i) = J(i-1) + \fracD(i-1,i)16 ] Tools