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TCP スループット・遅延計算機.
帯域幅遅延積、必要な TCP ウィンドウ、ウィンドウ・遅延・パケットロスで制限されるスループットを計算します。
CALCULATED IN YOUR BROWSER · NOTHING IS UPLOADED
64 KiB is the maximum without window scaling (RFC 7323).
Achievable TCP throughput6.55 Mbpslimited by receive window
- 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.
使い方: TCP スループット・遅延計算機
データを入力するかファイルを選び、設定を調整して結果を生成します。コピーやダウンロードの前に結果を確認してください。
制限と対応形式
入力内容はお使いの端末で処理されます。
英語の技術説明
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.