1961340 - Enable QUIC ECN reporting

Status: RESOLVED FIXED

(Core :: Networking, enhancement, P2)

Description

[Max Inden]

Bug 1918070 introduced the network.http.http3.ecn pref, enabled on Firefox Nightly. When true, Firefox would (a) mark and (b) report ECN.

Bug 1948739 enabled the pref on Firefox Beta.

With the pref set to true, we see around 2% of ECN blackholes, i.e. network paths that drop all ECN marked datagrams. Such a blackhole leads to significant connection establishment delay.

While we are hesitant to enable ECN marking on Firefox Release, we can already ship ECN reporting.

I suggest we split the ECN pref into two, one for marking (prone to ECN blackholes) and one for reporting (no known issues). The former we will keep on Beta only, the latter we can have ride the trains.

Comment 1

[Max Inden]

Attachment: Bug 1961340 - Enable QUIC ECN reporting r=leggert,kershaw

Bug 1918070 introduced the network.http.http3.ecn pref, enabled on
Firefox Nightly. When true, Firefox would (a) mark and (b) report ECN.

Bug 1948739 enabled the pref on Firefox Beta.

With the pref set to true, we see around 2% of ECN
blackholes, i.e. network
paths that drop all ECN marked datagrams. Such a blackhole leads to
significant connection establishment
delay.

While we are hesitant to enable ECN marking on Firefox Release, we can
already ship ECN reporting.

This commit splits the ECN pref into two, one for marking (prone to ECN
blackholes) and one for reporting (no known issues). The former we will
keep on Beta only, the latter we can have ride the trains.

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/51d59e861f38
Enable QUIC ECN reporting r=kershaw,necko-reviewers,valentin

Comment 3

[agoloman]

https://hg.mozilla.org/mozilla-central/rev/51d59e861f38