Mastering TCP: How SACK, Delayed ACK, and RTT Boost Performance Testing

Understanding TCP's Selective Acknowledgment (SACK), Delayed ACK, and Round‑Trip Time (RTT) mechanisms is essential for performance and fault testing, as they improve retransmission efficiency, balance latency and bandwidth, and influence timeout calculations, enabling engineers to design precise test scenarios and optimize network reliability.

Delayed ACKNetwork ProtocolsPerformance Testing

0 likes · 9 min read

Mastering TCP: How SACK, Delayed ACK, and RTT Boost Performance Testing

Liangxu Linux

Oct 19, 2020 · Information Security

Exploiting Linux’s DelayedACKLost Counter to Infer TCP Sequence Numbers

An imaginative tale reveals how two covert agents exploit the Linux kernel’s DelayedACKLost counter via /proc/net/netstat, using it to infer TCP sequence numbers and perform a side‑channel hijack, while illustrating the underlying delayed ACK mechanism, related kernel functions, and the security implications of this hidden metric.

Delayed ACKKernelLinux

0 likes · 8 min read

Exploiting Linux’s DelayedACKLost Counter to Infer TCP Sequence Numbers