Re: [Int-area] Comments on "per-app networking considerations" draft

[Sørensen , Frode]

Linda,

Many thanks for your feedback. I generally agree with your comment. However, 
the draft is discussing and comparing different approaches. 3GPP offers one 
approach, and could be considered a kind of managed approach for services 
produced internally to the 3GPP architecture. Another approach is the general 
internet access, and I suggest to drill deeper into the description of that 
architecture. My comments seek to supplement the discussion already included in 
the draft, and as far as I understand, general internet access is also in scope 
of the draft.

Thanks,
Frode

Fra: Linda Dunbar 
Sendt: tirsdag 6. juli 2021 18:00
Til: Sørensen, Frode ; int-area@ietf.org
Emne: RE: [Int-area] Comments on "per-app networking considerations" draft

Frode,

That is a good summary.

3GPP use the notion of “Application Controller” that controls the services for 
applications. It is less likely to be users or application themselves 
exchanging App characteristics with network operators, more like that the users 
and applications register with their specific controllers for the types of 
services they need. Then the Controller exchange with the network.

Linda Dunbar

From: Int-area mailto:int-area-boun...@ietf.org>> On 
Behalf Of Sørensen, Frode
Sent: Sunday, July 4, 2021 12:54 AM
To: int-area@ietf.org<mailto:int-area@ietf.org>
Subject: Re: [Int-area] Comments on "per-app networking considerations" draft

Many thanks for an interesting draft and follow-up discussion on the list. A 
couple of supplementary thoughts from my side:

1) Application-based vs. user-based (or user-controlled)

I think the draft could benefit from distinguishing between these two terms. 
The intro section mentions that “use cases where network operators, or 
applications, might desire for application traffic to be treated differently by 
the network”. Applications don’t have desires per se, while such desires come 
from some person, which could be the end-user, the application developer or 
network operator (if the latter has influence on the implementation of the user 
host, as the draft explains).

The discussion thread on the list is touching the distinction. The user-based 
approach, signalled from the application to the network, mentioned by Yiannis, 
is interesting. In my understanding, the user could either request specific QoS 
treatment per session, or the user could configure this in the application via 
some user-interface. In both cases, this selection would be user-controlled, as 
opposed to operator-controlled.

2) Application categories vs. traffic categories

The draft uses the terms “categories” and “classes” several times, which is an 
essential part of the discussion. I think the text could benefit from 
distinguishing more clearly between whether the categories/classes are 
“application categories” or “traffic categories”. The distinction may be 
subtle, and an example might illustrate the point:

It is essential whether the network operator is classifying the traffic (e.g. 
by using DPI) based on application characteristics – or the end-user is 
selecting any application for special treatment (whereby the corresponding 
traffic is marked). The former case could be understood as an application 
category (and would be application-specific), and the latter could be 
understood as a traffic category (and would be application-agnostic, since any 
application may belong to the traffic category).

3) Regarding application categories

Application categories are easy to relate to when discussing principles, but 
are not that easy when it comes to practical implementation. This is already 
covered to some extent by the discussion thread below, regarding zero-rating in 
particular. A major challenge is how to define the categories and how to decide 
which category specific applications belong to.

One might of course establish procedures regarding such questions (as 
elaborated in the email thread), but it is likely that there will anyway be 
borderline cases, and conflicts may occur. To that end, traffic categories 
which are user-controlled and application-agnostic will be significantly 
different from application categories. Therefore, I think it would be valuable 
to further clarify the description regarding categorization in the draft.


In my view, the draft describes an important topic, providing an 
implementation-independent overview of per-application networking, and 
discussing principal implications of such networking, which could be useful 
when considering different concrete implementations. I support continued 
development of the draft.

Best,
Frode


-- Original Message --
From: Yiannis Yiakoumis mailto:gyiakou...@gmail.com>>
Date: Thursday, June 17 2021 at 2:30 AM PDT
Subject: Re: [Int-area] Comments on "per-app networking considerations" draft
To: Lorenzo Colitti mailto:lore...@google.com>>
Cc: Int-area@ietf.org<mailto:Int-area@ietf.org&g

Re: [Int-area] Comments on "per-app networking considerations" draft

[Sørensen , Frode]

Many thanks for an interesting draft and follow-up discussion on the list. A 
couple of supplementary thoughts from my side:

1) Application-based vs. user-based (or user-controlled)

I think the draft could benefit from distinguishing between these two terms. 
The intro section mentions that “use cases where network operators, or 
applications, might desire for application traffic to be treated differently by 
the network”. Applications don’t have desires per se, while such desires come 
from some person, which could be the end-user, the application developer or 
network operator (if the latter has influence on the implementation of the user 
host, as the draft explains).

The discussion thread on the list is touching the distinction. The user-based 
approach, signalled from the application to the network, mentioned by Yiannis, 
is interesting. In my understanding, the user could either request specific QoS 
treatment per session, or the user could configure this in the application via 
some user-interface. In both cases, this selection would be user-controlled, as 
opposed to operator-controlled.

2) Application categories vs. traffic categories

The draft uses the terms “categories” and “classes” several times, which is an 
essential part of the discussion. I think the text could benefit from 
distinguishing more clearly between whether the categories/classes are 
“application categories” or “traffic categories”. The distinction may be 
subtle, and an example might illustrate the point:

It is essential whether the network operator is classifying the traffic (e.g. 
by using DPI) based on application characteristics – or the end-user is 
selecting any application for special treatment (whereby the corresponding 
traffic is marked). The former case could be understood as an application 
category (and would be application-specific), and the latter could be 
understood as a traffic category (and would be application-agnostic, since any 
application may belong to the traffic category).

3) Regarding application categories

Application categories are easy to relate to when discussing principles, but 
are not that easy when it comes to practical implementation. This is already 
covered to some extent by the discussion thread below, regarding zero-rating in 
particular. A major challenge is how to define the categories and how to decide 
which category specific applications belong to.

One might of course establish procedures regarding such questions (as 
elaborated in the email thread), but it is likely that there will anyway be 
borderline cases, and conflicts may occur. To that end, traffic categories 
which are user-controlled and application-agnostic will be significantly 
different from application categories. Therefore, I think it would be valuable 
to further clarify the description regarding categorization in the draft.


In my view, the draft describes an important topic, providing an 
implementation-independent overview of per-application networking, and 
discussing principal implications of such networking, which could be useful 
when considering different concrete implementations. I support continued 
development of the draft.

Best,
Frode


-- Original Message --
From: Yiannis Yiakoumis mailto:gyiakou...@gmail.com>>
Date: Thursday, June 17 2021 at 2:30 AM PDT
Subject: Re: [Int-area] Comments on "per-app networking considerations" draft
To: Lorenzo Colitti mailto:lore...@google.com>>
Cc: Int-area@ietf.org

On Tue, Jun 15, 2021 at 7:46 AM, Lorenzo Colitti 
mailto:lore...@google.com>> wrote:
On Tue, Jun 15, 2021 at 8:49 PM Yiannis Yiakoumis 
mailto:gyiakou...@gmail.com>> wrote:
The big challenge with category-based differentiation is definition and 
enforcement of categorization. There is significant experience from Europe's 
zero-rating implementation, where regulators approved category-based 
zero-rating, and more than 30 network operators implemented it (based on DPI). 
In my experience, a decentralized approach (where each operator defines 
categories themselves, and enforces them through a heavyweight implementation 
process like DPI) doesn't work well, especially for smaller apps that don't 
have the resources to work with operators, and end-up being in a bigger 
disadvantage when their large competitors participate in such programs.  As a 
reference point, we've seen 10% success rate and 8-months average integration 
time for an eligible music streaming company to participate in Europe's music 
zero-rating programs, when the most popular apps were available in most of them 
from the very beginning (more details on this here).

That's a good point. I think it would definitely be useful to note in the draft 
that categories can sometimes be difficult to define, coordinate, and enforce.

A good step forward would be to define a metric around time/cost to 
participate, and what advances would help reduce this. Tommy/Lorenzo --- what 
are your thoughts on