Gratuit · Réseau et infrastructure IT
Calculateur de débit TCP et latence.
Calculez le produit bande passante × délai, la fenêtre TCP nécessaire et le débit limité par la fenêtre, la latence et les pertes de paquets.
64 KiB is the maximum without window scaling (RFC 7323).
- Bandwidth-delay product
- 10 MB Data in flight needed to fill the link
- Window needed per stream
- 9,766 KiB
- Window scale shift needed
- 8
- Window-limited throughput
- 6.55 Mbps
- Loss-limited (Mathis model)
- No loss entered
- Link utilisation
- 0.7 %
- Time for the file
- 3.4 h
Same window at other distances
| RTT | Window-limited throughput | With this loss |
|---|---|---|
| 1 ms | 524.29 Mbps | 524.29 Mbps |
| 5 ms | 104.86 Mbps | 104.86 Mbps |
| 10 ms | 52.43 Mbps | 52.43 Mbps |
| 20 ms | 26.21 Mbps | 26.21 Mbps |
| 40 ms | 13.11 Mbps | 13.11 Mbps |
| 80 ms | 6.55 Mbps | 6.55 Mbps |
| 150 ms | 3.5 Mbps | 3.5 Mbps |
| 300 ms | 1.75 Mbps | 1.75 Mbps |
- Mathis et al. (1997) estimates loss-limited throughput for Reno-style congestion control: MSS ÷ RTT × 1.22 ÷ √loss. CUBIC and BBR behave differently, BBR especially under random loss.
- Linux auto-tunes windows up to net.ipv4.tcp_rmem / tcp_wmem maxima; Windows uses receive-window auto-tuning.
Comment utiliser cet outil: Calculateur de débit TCP et latence
Saisissez ou sélectionnez vos données. Réglez les options, générez le résultat puis vérifiez-le avant de le copier ou de le télécharger.
Limites et formats acceptés
Vos données sont traitées sur votre appareil.
Notes techniques en anglais
The loss model (Mathis et al.) describes Reno-style congestion control; CUBIC and BBR behave differently. Everything is calculated in your browser; nothing is sent or probed on the network.
Window-limited throughput = window ÷ RTT per stream. Loss-limited throughput = MSS ÷ RTT × 1.22 ÷ √loss. The achievable rate is the smallest of those and the link speed; BDP = bandwidth × RTT.
A 64 KiB window over 80 ms caps one TCP stream at 6.55 Mbps; filling 1 Gbps needs a 9.5 MiB window.