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.carpen...@gmail.com> 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 > _______________________________________________ Ietf mailing list Ietf@ietf.org https://www.ietf.org/mailman/listinfo/ietf
