Bandwidth-Delay Product

Enter bandwidth and RTT — the BDP gives the TCP window a connection needs to fully use the link. A theme that runs through the MTU/MSS article.

Notes

Window scaling. Without the TCP option from RFC 7323 the window is capped at 64 KiB. On fast links with high RTT that is not enough — the calculator flags it.
Ideal value. The BDP is the theoretical figure without loss or congestion. Real throughput sits below it.
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