Re: My comments to the press about RFC 2474

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On 2010-09-04 08:13, Richard Bennett wrote:
>  Thank you for replying Brian. I've not only read the requisite RFCs,
> I've also implemented DiffServ over 802.11e. My implementations, like
> those of everyone else who has done this, invoked the prioritization
> mechanisms in 802.11e. This is a very common case. Another common case
> implements DiffServ using 802.1d priorities.

Diffserv is about layer 3 queuing mechanisms. It isn't about mapping
to primitive layer 2 prioritisation.

We did keep backwards compatibility with IP Precedence in diffserv,
and I suppose one could implement those particular PHBs by mapping them
to layer 2 prioritisation. But the more subtle PHBs like EF and AF
simply cannot be mapped to preemptive priority queues without
destroying their defined semantics.

> If you want to say that DiffServ is not itself a priority scheme but
> rather a system for selecting the use of priority schemes at the Data
> Link (or comparable facilities,) you're making a distinction that's too
> fine for the press. 

No, I am not saying that. That is IMHO a faulty interpretation
of the intent of diffserv. In particular, I don't see how one can
read RFC 2597 and RFC 3246 and imagine that they can be mapped to
layer 2 priority.

> As Russ is now invoking your message to support his
> view that payment for premium service is contrary to the wishes of IETF,
> that's a problem.

He's not saying that. He's effectively saying what I'm saying: payment
models are outside the scope of the standards, which don't require any
particular payment model in order to perform their job.

   Brian

> 
> RB
> 
> On 9/3/2010 1:06 PM, Brian E Carpenter wrote:
>> Richard,
>>
>> Diffserv deals with multiple different queuing disiplines, which may
>> or may not be priority based. Please read RFC 2475 and if
>> you like, B.E. Carpenter and K. Nichols, Differentiated Services in
>> the Internet, Proc. IEEE, 90 (9) (2002) 1479-1494.
>>
>>      Brian
>>
>> On 2010-09-04 07:57, Richard Bennett wrote:
>>>   DiffServ is a prioritization scheme, Brian, how can you say it's not?
>>> IntServ is a reservation scheme, and DiffServ attempts to provide
>>> desired PHBs in practice by sorting packets into priority queues and
>>> invoking appropriate Link Layer  facilities, which are in most cases
>>> priority-based, such as 802.11e traffic classes.
>>>
>>> What on earth could the value of DSCPs be if they didn't map to traffic
>>> classes in the data link?
>>>
>>> RB
>>>
>>>   Brian E Carpenter<brian.e.carpenter@xxxxxxxxx>   wrote:
>>>> Russ,
>>>> It has been consistently hard to explain that diffserv is not a
>>>> prioritisation scheme, even within the technical community, let
>>>> alone to the regulators and the media. I think your comments as
>>>> quoted are as good as we can expect from journalists.
>>>> It should be a matter of concern to all of us here that the US FCC
>>>> isn't confused into regulating the technology. It would set a bad
>>>> precedent for regulators in other countries. I am making no comment
>>>> as to whether they should regulate carrier's charging practices; that's
>>>> entirely a national matter that shouldn't concern the IETF in any way.
>>>> Regards
>>>> Brian Carpenter
>>>> On 2010-09-03 05:47, Russ Housley wrote:
>>>>> I want the whole community to be aware of the comments that I made to
>>>>> the press yesterday. Clearly, these comments do not represent IETF
>>>>> consensus in any way. They are my opinion, and the reporter was
>>>>> told to
>>>>> express them as my opinion.
>>>>>
>>>>> One thing that I said was not captured quite right. The article says:
>>>>> "With services that require certain speeds to operate smoothly,
>>>>> such as
>>>>> Internet telephony, calls are given precedence over TV, Housley said."
>>>>> I actually said that DiffServ can be used to make sure that traffic
>>>>> associated with applications that require timely delivery, like voice
>>>>> and video, to give preference over traffic associated with
>>>>> applications
>>>>> without those demands, like email.
>>>>>
>>>>> The whole article is copied below, and it is online here:
>>>>> http://www.nationaljournal.com/njonline/tc_20100902_7144.php
>>>>>
>>>>> Russ
> 
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