Subject: [alto] Éric Vyncke's Discuss on draft-ietf-alto-performance-metrics-19: (with DISCUSS and COMMENT)

From: Éric Vyncke via Datatracker <[email-masked]>
Date: Mon, 22 Nov 2021 03:32:09 -0800

Éric Vyncke has entered the following ballot position for
draft-ietf-alto-performance-metrics-19: Discuss

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----------------------------------------------------------------------
DISCUSS:
----------------------------------------------------------------------

Thank you for the work put into this document. Please bear with my lack of
knowledge about ALTO in general.

Please find below one trivial blocking DISCUSS points (probably easy to
address), some non-blocking COMMENT points (but replies would be appreciated
even if only for my own education), and some nits.

Special thanks to Jan Seedorf for the shepherd's write-up about the WG
consensus (even if not using the usual template).

I have appreciated the "operational considerations" section as it addresses
many questions that popped up during reading the document; notably, how can the
ALTO server measure any metric between the ALTO client and a resource.

I hope that this helps to improve the document,

Regards,

-éric

== DISCUSS ==

-- Section 4.1.3 --
A very trivial DISCUSS to fix: this document relies on RFC 8312 to specify how
TCP throughput is estimated but RFC 8312 does not appear in the normative
reference list (this will probably generate a down ref though).

----------------------------------------------------------------------
COMMENT:
----------------------------------------------------------------------

== COMMENTS ==

Minor regret about the examples as they are all about the IPv4 address family
especially in a world of happy eyeballs where the IPv4 and IPv6 paths may still
have different performance metrics.

-- Section 2.1 --
Should the figure 1 use "perf monitoring tools" rather than "management tool" ?

-- Section 4 --
This section title is about 'bandwidth' but the first sub-section is about
'throughput', while these concepts are related they are also distinct. How can
the reader reconciliate them ?

-- Section 4.1 --
Is the intent of ALTO to only work for TCP and not for other transport
protocols ? I.e., is QUIC out of scope ?

-- Section 4.2.3 --
Where are those 'tunnels' in "by subtracting tunnel reservations " coming from
? Probably about RSVP-TE but what is the link with ALTO ? (Again I am not
familiar with ALTO so this may be an uneducated question).

== NITS ==

-- Section 3.1.3 --
Probably tedious to do but why not replacing "TBA" by the actual value in the
examples for 'content-length' ?

---

From: Martin Duke <[email-masked]>
Date: Mon, 22 Nov 2021 07:40:39 -0800

Thanks Eric,

I think you mean RFC 8321? I am in the early stages of AD sponsoring a
draft to update that to PS. The authors have the choice of doing a downref
or referring to 8321bis and being stuck in the RFCEd queue for a few extra
months.

---

From: "Eric Vyncke (evyncke)" <[email-masked]>
Date: Mon, 22 Nov 2021 15:54:09 +0000

Martin,

The text in § 4.1.3 says:
   Intended Semantics: To give the throughput of a TCP congestion-
   control conforming flow from the specified source to the specified
   destination; see [RFC3649, Section 5.1 of RFC8312<https://datatracker.ietf.org/doc/html/rfc8312#section-5.1>] on how TCP
   throughput is estimated.  The spatial aggregation level is specified
   in the query context (e.g., PID to PID, or endpoint to endpoint).

So, it is RFC 8312 in the text, RFC 8312 is vaguely related to TCP bandwidth

-éric

From: Martin Duke <[email-masked]>
Date: Monday, 22 November 2021 at 16:40
To: Eric Vyncke <[email-masked]>
Cc: The IESG <[email-masked]>, alto-chairs <[email-masked]>, "[email-masked]" <[email-masked]>, IETF ALTO <[email-masked]>, Jan Seedorf <[email-masked]>
Subject: Re: Éric Vyncke's Discuss on draft-ietf-alto-performance-metrics-19: (with DISCUSS and COMMENT)

Thanks Eric,

I think you mean RFC 8321? I am in the early stages of AD sponsoring a draft to update that to PS. The authors have the choice of doing a downref or referring to 8321bis and being stuck in the RFCEd queue for a few extra months.

On Mon, Nov 22, 2021 at 3:32 AM Éric Vyncke via Datatracker <[email-masked]<mailto:[email-masked]>> wrote:
Éric Vyncke has entered the following ballot position for
draft-ietf-alto-performance-metrics-19: Discuss

Regards,

-éric

== DISCUSS ==

-- Section 4.1.3 --

== COMMENTS ==

-- Section 2.1 --

-- Section 4 --

-- Section 4.1 --

-- Section 4.2.3 --

== NITS ==

-- Section 3.1.3 --

---

From: Martin Duke <[email-masked]>
Date: Mon, 22 Nov 2021 08:39:59 -0800

Good catch!

I'm not sure that either of these references are actually directly relevant
to the subject, though I'm happy to be convinced otherwise.

It might be that one of the IPPM docs (RFC 8337?) might be a better fit.

If RFC 8312 is the right answer, 8312bis is almost done and they can simply
update to avoid the downref.

Martin

On Mon, Nov 22, 2021 at 7:54 AM Eric Vyncke (evyncke) <[email-masked]>
wrote:

>    destination; see [RFC3649, Section 5.1 of RFC8312
> <https://datatracker.ietf.org/doc/html/rfc8312#section-5.1>] on how TCP
>
> *From: *Martin Duke <[email-masked]>
> *Date: *Monday, 22 November 2021 at 16:40
> *To: *Eric Vyncke <[email-masked]>
> *Cc: *The IESG <[email-masked]>, alto-chairs <[email-masked]>, "
> [email-masked]" <
> [email-masked]>, IETF ALTO <[email-masked]>,
> Jan Seedorf <[email-masked]>
> *Subject: *Re: Éric Vyncke's Discuss on
> draft-ietf-alto-performance-metrics-19: (with DISCUSS and COMMENT)
>
>
>
> Thanks Eric,
>
>
>