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THE FEUTEX TOOLKIT

TCP RTO Estimator Update

Apply one RFC 6298 RTT estimator update using the previous smoothed values.

Networking workspace● Runs in your browser
01 Your input
02 Your result
View or copy raw result data
FormulaSRTT←7/8 SRTT+1/8 R; RTTVAR←3/4 var+1/4|old SRTT−R|
Sources and model references

Worked example

Inputs

Previous SRTT
0.1 s
Previous RTTVAR
0.02 s
New RTT sample
0.14 s
Clock granularity
0.001 s

Expected results

Updated SRTT
0.105 s
Updated RTTVAR
0.025 s
RTO with one-second floor
1 s

Load the example in the workspace to reproduce these results. Display rounding does not change the underlying calculation.

How to use this tool

  1. Enter the labeled inputs in the indicated units.
  2. Calculate and compare every output against the stated model assumptions.

Try this example

{
  "srtt": 0.1,
  "var": 0.02,
  "sample": 0.14,
  "g": 0.001
}

Accuracy and scope

Established estimator, non-retransmitted sample, RFC recommended floor; excludes backoff and implementation-specific bounds. Simplified analytical model; not a design recommendation or safety certification.

Is my data uploaded?

This tool runs locally in your browser. Input and output are not sent to a processing server. Copy or download your result before leaving the page.