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TCP Retransmission Impact Calculator

Calculate TCP throughput impact from packet loss and retransmission overhead

Average round-trip time of the network path. Affects RTO calculation and throughput directly.
ms
Percentage of packets lost. TCP must retransmit lost packets, reducing effective throughput significantly.
%
Maximum TCP receive window in KB. Default is 64 KB; window scaling (RFC 7323) can increase to 1 GB. Larger windows improve throughput on high-BDP paths.
KB
Number of parallel TCP connections. Multiple connections can aggregate throughput but increase overhead.
flows
Maximum bandwidth of the bottleneck link.
Mbps

Per-Connection Performance

Window-Limited ThroughputMbps
Mathis Throughput (loss-limited)Mbps
Effective Throughput per FlowMbps
Bandwidth-Delay ProductKB

Retransmission Analysis

Initial RTOms
Goodput / Throughput Ratio%
Retransmission Overhead%
Avg Retransmissions per 1000 pkts

Aggregate Performance

Total Aggregate ThroughputMbps
Link Utilization%
Window Scale Needed
References: Mathis et al. "The macroscopic behavior of the TCP congestion avoidance algorithm" (1997). RFC 6298 (RTO computation). RFC 7323 (TCP window scaling). BDP = bandwidth x RTT.