Subject: Genart last call review of draft-ietf-quic-applicability-14

From: Ines Robles via Datatracker <[email-masked]>
Date: Mon, 07 Feb 2022 16:03:42 -0800

Reviewer: Ines Robles
Review result: Ready with Issues

I am the assigned Gen-ART reviewer for this draft. The General Area
Review Team (Gen-ART) reviews all IETF documents being processed
by the IESG for the IETF Chair.  Please treat these comments just
like any other last call comments.

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Document: draft-ietf-quic-applicability-14
Reviewer: Ines Robles
Review Date: 2022-02-07
IETF LC End Date: 2022-02-07
IESG Telechat date: Not scheduled for a telechat

Summary:

This document discusses the applicability of the QUIC transport protocol,
focusing on caveats impacting application protocol  development and deployment
over QUIC.  The document is well written and clear.

I have one minor issue.

Major issues: None

Minor issues:

Section 2 on the sentence:

"While recent measurements have shown no evidence of a widespread,  systematic
disadvantage of UDP traffic compared to TCP in the Internet"

Statement of "no evidence of a widespread,  systematic disadvantage" may be
seen as misleading when the example is about networks that simply block UDP
traffic without considering other possible disadvantages, moreover when one of
the references specifically states the opposite "3% failure is a lot".
Additionally references are rather old (2016) materials. Suggestion for
avoidance of doubt:

"Measurements have shown 3-5% of networks blocking UDP, constituting a
disadvantage of UDP traffic compared to TCP in the Internet [Edeline16],
[Trammell16] [Swett16].  All applications running on top of QUIC must
therefore..."

Nits: None

Thanks for this document,
Ines.

---

From: "Brian Trammell (IETF)" <[email-masked]>
Date: Wed, 9 Feb 2022 18:11:02 +0100

hi Ines,

Many thanks for the review! We've proposed alternate text to address the issue in https://github.com/quicwg/ops-drafts/pull/451.

NEW:

Measurement studies have shown between three {{Trammell16}} and
five {{Swett16}} percent of networks block all UDP traffic, though there
is little evidence of other forms of systematic disadvantage to UDP traffic
compared to TCP {{Edeline16}}. This blocking implies that all applications
running on top of QUIC must either be prepared to accept connectivity failure
on such networks, or be engineered to fall back to some other transport
protocol. In the case of HTTP, this fallback is TLS over TCP.

We'd like to keep the systematic disadvantage language and the reference to
Edeline, as it underscores the fact that the majority of expected UDP
disadvantage is simple blockage, thereby making fallback a viable strategy.

We did strike "recent" -- the adjective applied when the text was written in 2017.

Thanks again, cheers,

Brian

> On 8 Feb 2022, at 01:03, Ines Robles via Datatracker <[email-masked]> wrote:
> 
> Reviewer: Ines Robles