Bugzilla – Full Text Bug Listing |
Summary: | Missing RTT measurement due to Retransmission Timeout | ||
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Product: | ns-3 | Reporter: | Jonah Ho <ho.jonah> |
Component: | tcp | Assignee: | natale.patriciello |
Status: | PATCH WANTED --- | ||
Severity: | enhancement | CC: | ho.jonah, ns-bugs |
Priority: | P3 | ||
Version: | ns-3.28 | ||
Hardware: | Mac Intel | ||
OS: | Mac OS | ||
Attachments: |
TCP Log Output
This is how I output m_history and RTT. |
Description
Jonah Ho
2018-08-19 15:50:48 EDT
Created attachment 3159 [details]
TCP Log Output
PDF is too big, attaching as link.
Created attachment 3160 [details]
This is how I output m_history and RTT.
https://tools.ietf.org/html/rfc6298 3. Taking RTT Samples TCP MUST use Karn's algorithm [KP87] for taking RTT samples. That is, RTT samples MUST NOT be made using segments that were retransmitted (and thus for which it is ambiguous whether the reply was for the first instance of the packet or a later instance). The only case when TCP can safely take RTT samples from retransmitted segments is when the TCP timestamp option [JBB92] is employed, since the timestamp option removes the ambiguity regarding which instance of the data segment triggered the acknowledgment. We intentionally do not take RTT from a retransmitted segment. However, as you can read, that is possible when using the timestamp option, even if I don't know what the RTT of a retransmitted segment is. Patch welcome, and this is a feature request, not a bug report. |