RTO.Initial = 1 second for TCP
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Authored by tuexen on Jan 24 2019, 5:18 PM.

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Reviewers

rscheff
rrs
lstewart
jtl
kbowling

Group Reviewers

transport

Commits

rS347096: MFC r344368:
rS344368: Reduce the TCP initial retransmission timeout from 3 seconds to

Summary

This patch reduces the Initial RTO from 3 seconds to 1 second as allowed by RFC6298.

We might want to change the backoff factors for SYN segments first. Without that the lifetime of SYN-cache entries might be too short. To be discussed on the bi-weekly transport telco.

Test Plan

Use the attached packetdrill srcipt:

tcp-syn-ack-rtx.pkt2 KBDownload

Diff Detail

Repository

rS FreeBSD src repository - subversion

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Event Timeline

tuexen created this revision.Jan 24 2019, 5:18 PM

Herald added 1 blocking reviewer(s): transport. · View Herald TranscriptJan 24 2019, 5:18 PM

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Harbormaster completed remote builds in B22122: Diff 53158.Jan 24 2019, 5:18 PM

Should be adding RFC6298 to https://wiki.freebsd.org/TransportProtocols/tcp_rfc_compliance too...
Good that RFC2988 is marked obsolete there already - but i think that is only tracking the RFC state, not the state of which RFC the stack mostly conforms to.

(Suggestion: after this change, have the RFC2988 line in the table, but with strikethrough, and add a new line for 6298.

I support this enhancement!