The MPLS WG Archive[Date Prev][Date Next][Thread Prev][Thread Next] [Date Index][Thread Index][Author Index][Subject Index] Last call comments
Eric, At 10:29 28/06/2000 -0700, Eric Gray wrote: >Francois, > > Thanks for the well considered replies. > > See several embedded replies below. Please >pardon the numerous "clippings". > > >> > I have clipped the parts Shahram has already answered. >> >> > The draft punts on several relevant issues. In >> >particular, there seems to be no effort to justify >> >some of the complexity in the specification in terms >> >of real world applications for particularly difficult >> >combinations (such as the combination of Uniform model >> >and PHP). If the uniform model is intended for the >> >> See above. You may have missed the earlier discussions on >> the alias but this was discussed. and there is corresponding >> text in the spec already giving an example of where uniform >> is useful. > >I did a search (using Netscape's 'Search Messages' function) >for all MPLS related messages containing the word 'uniform'. >I also read the minutes from Adelaide (I'm not going to be >forever apologizing for not having been able to get there). Refering to earlier discussion was not to prompt apologies from you, it was to let you know that there is some earlier discussion that are worth considering before jumping to any conclusion. >The 'discussion' in each case was decidedly one-sided. I >did not notice anyone, other than the authors of the draft, >clamoring for inclusion of the uniform model. I did a like Most discussion on this topic actually happened before we proposed applying the work of "Diff-Serv over Tunnel" to MPLS. Consequently, it happened before the terms uniform and pipe were proposed. Ken Ballou initiated a thread which lead to an argument for support of uniform model. Also, you will find included at the bottom a email from Curtis which I take as an endorsment of the proposal for Uniform model and pipe model. Neither are co-authors. I have not seen a single message arguing against support of uniform model until yours (there's been messages arguing for pipe model but those were not arguing against uniform model). So, I'll just assume your above judgment of one-sidedness resulted from an incomplete "search" on related material. >search in the DiffServ mailing list - which I already said >something about in a different message - and found a similar >silence from the throngs. > >This is the first draft in which the two models are discussed >and it is also the draft on which we have been asked to give >last call comments. I stated that the Uniform model is not >sufficiently well documented and should be removed. You say >it stays. > >Sounds perfectly reasonable to me. You still need to address >the issue that it is not sufficiently well documented. > Shahram's working on this with you. >> >> >In addition, the following definitions would be useful >> >(collected in a glossary?): >> > >> >Behavior Aggregate >> > Packets crossing a link that require >> > the same Diff-Serv behavior. >> >Diff-Serv Differentiated Services. >> >Diff-Serv Context >> > <Insert Definition HERE> >> >FEC <Insert Definition HERE> >> >Ordered Aggregate >> > Set of Behavior Aggregates sharing an >> > ordering constraint. >> >PHB Scheduling Class >> > Set of PHBs applicable to an Ordered >> > Aggregate. >> > >> > >> >> I would prefer to leave them out. > >Okay by me. It might be useful if there was a statement >somewhere stating where these definitions can be found. >Of course, if the answer is not simple, it might be easier >to just include the definitions. There are precedents >among the other MPLS drafts. > Current draft already has the following references in section 1: "The Diff-Serv model defines [DIFF_NEW] the set of Behavior Aggregates which share an ordering constraint to constitute an "Ordered Aggregate (OA)". It also defines the set of one or more PHBs that are applied to this set of Behavior Aggregates to constitute a "PHB Scheduling Class (PSC)"." "In a Differentiated Service (Diff-Serv) domain [DIFF_ARCH] all the IP packets crossing a link and requiring the same Diff-Serv behavior are said to constitute a Behavior Aggregate (BA)" what more exactly do you suggest we need? thanks Francois >> >> Francois >> -------- >> > >In message <336ECDAFDF7DD311B9E30090277AEE4101B40467@nt-exchange-bby.pmc-sierra >.bc.ca>, Shahram Davari writes: >> Curtis, >> >> "uniform" model means that the LSP tunnel will treat the packets consistent >> with the treatment that the packet would get if there was no LSP tunnel. >> this is useful when both the tunnel and the network on its ingress/egress >> belong to the same administrative domain. >> >> "Tunnel" mode means that the packets may be treated differently (under >> another PHB) when they are passing through the LSP, but as soon as they >> emerge from the other side of the Tunnel, they will continue with their >> original PHB (the PHB before entering the Tunnel). This may be useful when a >> service provider wants to Tunnel its traffic through another administrative >> domain. For example a service provider A may need to pass AF-PHB traffic >> through domain B (which is not under his control and offers only EF-PHB). >> >> Regards, >> -Shahram > > >Francois' prior message makes sense now. > >Thanks, > >Curtis _________________________________________________________________ Francois Le Faucheur Development Engineer, IOS Layer 3 Services Cisco Systems Office Phone: +33 4 92 96 75 64 Home Office Phone: +33 4 92 94 00 78 Mobile : +33 6 89 108 159 Vmail: +33 1 58 04 62 66 Fax: +33 4 92 96 79 08 Email: flefauch@cisco.com _________________________________________________________________ Petra B - Les Lucioles - 291, rue Albert Caquot - 06560 Valbonne - France _________________________________________________________________
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