Er, exactly what in your quotation is incompatible with what I wrote: >>> Diffserv deals with multiple different queuing disiplines, which may or may >>> not be priority based.
? Regards Brian Carpenter On 2010-09-04 09:34, Richard Bennett wrote: > Brian's paper on DiffServ confirms the fact that prioritization is part of > the > standard. Here are the two relevant quotes: > > "In the original design of IP [33], a byte known as the “type of service > (TOS) > octet” was reserved in the header of every packet. This was defined to > contain > two important fields: a three-bit “precedence” value and three TOS bits. The > precedence was intended as a simple priority marker, where priority 0 got the > worst treatment and priority 7 got the best." (p. 1480) > > "The Diffserv working group has taken the approach that a few fundamental > PHBs > should be standardized early. These should derive from some existing > experience > (primarily from limited deployment and experimentation with use of the IP > precedence field to select forwarding behaviors) and might be implemented > using > a variety of specific mechanisms. The PHBs standardized so far are as > follows... > > "• Class selector behaviors: here seven DSCP values run from 001 000 to 111 > 000 > and are specified to select up to seven behaviors, each of which has a higher > probability of timely forwarding than its predecessor. *Experts will note > that > the default behavior plus the class selectors exactly mirror the original > eight > IP Precedence values.*" (p. 1487) > > This is very straightforward. > > 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 > > -- > Richard Bennett > Senior Research Fellow > Information Technology and Innovation Foundation > Washington, DC > _______________________________________________ Ietf mailing list Ietf@ietf.org https://www.ietf.org/mailman/listinfo/ietf