TCP SACK ·
Map the Gaps, Not the Window
un
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.com · RFC 2018 · Multi-loss recovery in one RTT
SACK blocks
0
Retransmits
0
State
—
In flight
SACKed / arrived
cumACK edge
Lost / missing
Recovered
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Un
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.com · TCP SACK
Un
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.com · TCP Selective Acknowledgment (SACK): Recovering Multiple Losses Without Retransmitting the Whole Window