Subject: Re: Last Call: draft-ietf-tsvwg-diffserv-class-aggr (Aggregation of DiffServ Service Classes) to Informational RFC

From: Pekka Savola <[email-masked]>
Date: Tue, 2 Oct 2007 17:11:10 +0300 (EEST)

On Mon, 1 Oct 2007, The IESG wrote:
> The IESG has received a request from the Transport Area Working Group WG
> (tsvwg) to consider the following document:
>
> - 'Aggregation of DiffServ Service Classes '
>   <draft-ietf-tsvwg-diffserv-class-aggr-04.txt> as an Informational RFC

DiffServ Pool 1 codepoints require Standards Action [1].  While this 
document doesn't define new ones (because there aren't any), it 
defines how one should configure the treatment for each and every Pool 
1 codepoint in the network.  Therefore in spirit it specifies DSCP 
codepoint behaviour and how those should be used.

As such I believe this document is inappropriate as an Informational 
RFC.

It is not clear that consensus in the IETF and deployments is strong 
enough to approve/recommend any specific treatment for standards track 
DSCP values.

If this work were to proceed, I suggest that first RFC 4594, which 
this document builds on, would attain IETF consensus by following the 
standards process for publication as a BCP.

[1]
http://www.iana.org/assignments/dscp-registry

-- 
Pekka Savola                 "You each name yourselves king, yet the
Netcore Oy                    kingdom bleeds."
Systems. Networks. Security. -- George R.R. Martin: A Clash of Kings

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---

From: ken carlberg <[email-masked]>
Date: Tue, 2 Oct 2007 10:40:57 -0400

On Oct 2, 2007, at 10:11 AM, Pekka Savola wrote:

> It is not clear that consensus in the IETF and deployments is  
> strong enough to approve/recommend any specific treatment for  
> standards track DSCP values.

could you expand on this observation?

-ken

---

From: Brian E Carpenter <[email-masked]>
Date: Wed, 03 Oct 2007 09:31:04 +1300

Pekka,

[FYI I've already indicated my support for this draft
in a message sent to the IESG.]

On 2007-10-03 03:11, Pekka Savola wrote:
> document doesn't define new ones (because there aren't any), it defines 
> how one should configure the treatment for each and every Pool 1 
> codepoint in the network.  Therefore in spirit it specifies DSCP 

I think this is really not a valid interpretation. It's very common in
the IETF to produce the first version of operational recommendations
as Informational, with the possibility of producing a later version
as BCP when there's successful operational experience. I believe
that this draft, and RFC 4594, are in that category. IMHO they do
not significantly change the implementation requirements for the
various Proposed Standard diffserv PHBs; they add configuration
recommendations for those PHBs, which is a perfectly legitimate
thing for an Informational RFC.

To be clear, the notion of reclassifying diffserv traffic at
a domain boundary is a fundamental part of the diffserv
architecture, and remapping diffserv classes into treatment
aggregates, as this draft describes, is just an example of
such reclassification. This draft does not change the diffserv
architecture and does not redefine any of the standards track
PHBs. To quote an example from the text:
    Traffic in the Real Time treatment aggregate should be carried in a
    common queue or class with a PHB as described in RFC 3246 [11] and
    RFC 3247 [12].

> 
> As such I believe this document is inappropriate as an Informational RFC.
> 
> If this work were to proceed, I suggest that first RFC 4594, which this 
> document builds on, would attain IETF consensus by following the 

Not until there is significant operational feedback, which is still
a year or three in the future. I don't see that this draft, or
RFC 4594, is significantly different in that respect from, say,
RFC 4472.

     Brian

---

From: Pekka Savola <[email-masked]>
Date: Thu, 4 Oct 2007 09:35:27 +0300 (EEST)

On Tue, 2 Oct 2007, ken carlberg wrote:
>> It is not clear that consensus in the IETF and deployments is strong enough 
>> to approve/recommend any specific treatment for standards track DSCP 
>> values.
>

I don't recall when was the last (Diffserv-based) QoS talk at NANOG or 
similar operator-rich meeting.  (Sure, there is the tutorial, but it 
doesn't count.)

Seems like a potential indication that most typical ISPs aren't 
working on or interested in this, this stuff is so trivial, or that 
coordination is not necessary.

---

From: Marshall Eubanks <[email-masked]>
Date: Thu, 4 Oct 2007 07:04:17 -0400

On Oct 4, 2007, at 2:35 AM, Pekka Savola wrote:

> I don't recall when was the last (Diffserv-based) QoS talk at NANOG  
> or similar operator-rich meeting.  (Sure, there is the tutorial,  
> but it doesn't count.)
>

Dear Pekka;

FWIW, in the video conferencing world, DiffServe QOS is ubiquitous.  
(This is pretty frequently over internetworks, but not generally over  
the Internet.) The same is true for IPTV, but of course this is not  
yet internetwork much. I would rate it as too simple and too deployed  
for NANOG.

Regards
Marshall

---

From: ken carlberg <[email-masked]>
Date: Thu, 4 Oct 2007 12:38:24 -0400

> or similar operator-rich meeting.  (Sure, there is the tutorial,  

I would be concerned if outside groups spent time arguing "foo" is  
bad, or if they advocated other positions to the same issue.  But I  
tend to feel quite uncomfortable with litmus tests based on  
inactivity of other groups/people.  My personal view is that  
advocates of that line of reasoning place a bigger burden on  
themselves in providing specific in-depth arguments.

> coordination is not necessary.

i appreciate work that is trivial because its generally simple, easy  
to accomplish, and leads to fewer interoperability issues.  as for  
ISPs, its fascinating the disparity of how quiet and talkative they  
are depending on what side of the NDA you are on :-)

cheers,

-ken

---

From: Brian E Carpenter <[email-masked]>
Date: Fri, 05 Oct 2007 10:26:59 +1300

On 2007-10-05 05:38, ken carlberg wrote:
> I would be concerned if outside groups spent time arguing "foo" is bad, 
> or if they advocated other positions to the same issue.  But I tend to 
> feel quite uncomfortable with litmus tests based on inactivity of other 
> groups/people.  My personal view is that advocates of that line of 
> reasoning place a bigger burden on themselves in providing specific 
> in-depth arguments.
> 
> i appreciate work that is trivial because its generally simple, easy to 
> accomplish, and leads to fewer interoperability issues.  as for ISPs, 
> its fascinating the disparity of how quiet and talkative they are 
> depending on what side of the NDA you are on :-)

In any case, if Pekka is correct, that's *exactly* why this
draft and RFC 4594 are needed - to lay a minimum foundation on which
ISPs can build operational practices and SLAs.

It's always been clear to me that voice and video would be the main
drivers for uptake of diffserv, and Marshall's comments confirm
that. As that type of traffic grows, ISPs won't have any choice.
Guidnace from the IETF seems entirely appropriate.

      Brian

---

From: Magnus Westerlund <[email-masked]>
Date: Tue, 16 Oct 2007 10:00:28 +0200

Hi,

My reading of this thread of comments is that there is no reason to
change anything regarding the document. I will therefore progress this
document towards approval.

Regards

Magnus Westerlund

Brian E Carpenter skrev:
>>> or similar operator-rich meeting.  (Sure, there is the tutorial, but
>>> it doesn't count.)
>>
>> tend to feel quite uncomfortable with litmus tests based on inactivity
>> of other groups/people.  My personal view is that advocates of that
>> line of reasoning place a bigger burden on themselves in providing
>> specific in-depth arguments.
>>

-- 

Magnus Westerlund

IETF Transport Area Director & TSVWG Chair
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