Subject: Re: [Int-dir] INTDIR review of draft-ietf-mif-happy-eyeballs-extension-09

From: GangChen <[email-masked]>
Date: Thu, 16 Jun 2016 15:59:57 +0800

Dear Ralph,

I apologize for this late reply.
Thank you for the comments.
Those are informative for us.
Please see my replies inline.

2016-05-04 5:15 GMT+08:00, Ralph Droms <[email-masked]>:
> I am an assigned INT directorate reviewer for
> draft-ietf-mif-happy-eyeballs-extension-09. These comments were
> written primarily for the benefit of the Internet Area
> Directors. Document editors and shepherd(s) should treat these
> comments just like they would treat comments from any other IETF
> contributors and resolve them along with any other Last Call comments
> that have been received. For more details on the INT Directorate, see
> http://www.ietf.org/iesg/directorate.html.
>
> In my opinion, the documents lacks - and needs - a clear statement of
> purpose.  What result is the document trying to achieve?  Who is the
> audience?  How would the audience put the contents of the document to
> use?

the draft mainly intends to address the issue where a node has
selected an interface
and obtained a valid IP address from the network,  but Internet connectivity
is not available. Such scenario is described in the "WiFi is broken"
of use cases section.
The purpose of HE-MIF is to avoid such issue. The audience is supposed
to be connection manager implementors or web browser developer, who
could integrate the HE-MIF framework into their implementations.

This comment inspire me to re-construct the draft to clear the purpose
statement.
It's may probably be better to combine section 1 and 3, since the
section 3 is major use cases description that may help to state the
issue HE-MIF targeted.

> The document must be edited carefully for english language usage
> before publication.  I would consider this issue to be worthy of a
> "Discuss" on the document.  I found that the document is unclear in
> several areas, which prevented me from understanding the meaning of
> that text.  For example, in section 2, does "within a single home."
> mean a device in one home or a device with just one interface?  In
> section 5.1, does:
>
>  users may dedicatedly prefer a 3GPP
>  network interface to seek high-reliability or security benefits even
>  to manually turn off WiFi interface.
>
> mean:
>
>  users may turn off a device's WiFi interface to guarantee use of a
>  3GPP network interface to assure higher reliability or security.

Your interpretation is correct and great example to me.
I have realized there are several similiar language issues.
Those days, I'm inviting english knowledged persons to help me fix the bugs.
we will publish an new version to promote the readability.

> Some sections seem to make observations about conditions that might
> have an influence on an implementation of MIF-HE, but don't have any
> actionable guidance for implementors.  This lack of clarity is related
> to the lack of a clear statement of purpose for the document.  For
> example, in section 5.1:
>
>  The decision on mergence of
>  policies may be made by implementations, by node administrators, even
>  by other standards investigating customer behavior.  However, it's
>  worth to note that a demand from users should be normally considered
>  higher priority than from other actors.
>
> I don't see anything in this text that I would consider actionable as
> an implementor.

The draft is virtually not a algorithm, but requirements for the
algorithm or implementations.
The section 5.1 reflects the wg discussion outcome. The actionable for
implementors is to open an interface to accept user's input expressing
their preference. And, this preference should be superior to other
inputs.

> It is unclear where the document explicitly choosing one interface as
> "faster".  Section 5.2 includes text about "the outcome of each
> connection attempt"; does this text refer to recording the connection
> time and using that time as the basis for future interface selection?

It's correct. A timer is used to flush each cache entry and triger
next connection attempt.

> How does HE-MIF interact with HE for selecting between IPv4 and IPv6?

HE-MIF and HE are two parallel threads. They don't have compulsive
interactions.
In other words, a device use HE-MIF to choose the faster interface,
afterwards it may
use HE to select suitable IP family or it just uses default address
selection to determine.

I hope above could clarify.

Many thanks

Best Regards

Gang