Hi, Here's the review I promised earlier. I still think it would be best to not publish the draft for the reasons I mentioned earlier. In case the IETF wants to move this document forward I think at least a number of things need to change:
a) The document makes a number of assertions that I think are not correct. E.g. it states that the solutions must be implementable in software. I cannot recall that there was any assertion about whether some, all or none of the things that the requirements documents prescribe should be build in HW or SW. A vendor needs to build equipment that fulfills the requirements, the standard needs to specify mechanisms that fulfill the requirements. If a vendor can build it in SW fine, if it has to be done in HW fine. But the main point is that everything needs to fulfill the specs which fulfill the requirements. b) The complexity sausage needs to go. The section does not help the goal of the document or the relevant parts are duplicated later in the text. c) Some text passages are overly dramatic and could use a little down-toning (e.g. " (something that would inevitably drive all customers away!)"). Others use absolute figures for speculative things (like increases cost by a factor of two etc.). Yet others are not very polite to certain vendors like "forces all serious router vendors to implement both protocols". I am not sure the IETF wants to call router vendors to be "not serious" if they only implement either OSPF or ISIS. The basic message is the text needs a serious cleanup of language. d) Section 6 needs to go. I do not think that these coexistence models are agreed by the wider IETF community and I don't think they help the message of the document. e) The document should provide more references for some of the statements that caused dispute on the list. Best, Rolf NEC Europe Limited | Registered Office: NEC House, 1 Victoria Road, London W3 6BL | Registered in England 2832014 > -----Original Message----- > From: [email protected] [mailto:[email protected]] On Behalf Of > Rolf Winter > Sent: Dienstag, 4. Oktober 2011 11:17 > To: Brian E Carpenter; [email protected] > Cc: [email protected] > Subject: RE: Last Call: <draft-sprecher-mpls-tp-oam-considerations- > 01.txt> (The Reasons for Selecting a Single Solution for MPLS-TP OAM) > to Informational RFC > > Hi, > > I think Brian makes an excellent point here. RFC 1958 already contains > exactly the same basic message (just with far less (unnecessary) words). > I don't think we need this document as it doesn't really add anything > to what RFC 1958 says. I'll provide a more detailed review later. > > Best, > > Rolf > > > NEC Europe Limited | Registered Office: NEC House, 1 Victoria Road, > London W3 6BL | Registered in England 2832014 > > > > -----Original Message----- > > From: [email protected] [mailto:[email protected]] On Behalf > Of > > Brian E Carpenter > > Sent: Freitag, 30. September 2011 21:48 > > To: [email protected] > > Cc: [email protected] > > Subject: Re: Last Call: <draft-sprecher-mpls-tp-oam-considerations- > > 01.txt> (The Reasons for Selecting a Single Solution for MPLS-TP OAM) > > to Informational RFC > > > > Huub, > > > > On 2011-09-30 20:19, Huub van Helvoort wrote: > > > All, > > > > > > Section 1,1 also contains the text: > > > [RFC5317] includes the analysis that "it is technically feasible > > that > > > the existing MPLS architecture can be extended to meet the > > > requirements of a Transport profile, and that the architecture > > allows > > > for a single OAM technology for LSPs, PWs, and a deeply nested > > > network." > > > > > > This is a quote from slide 113 in the PDF version of RFC5317 and > > should > > > be read in realtion to the statement on slide 12 of the same RFC: > > > > > > "This presentation is a collection of assumptions, discussion > points > > > and decisions that the combined group has had during the months of > > > March and April, 2008 > > > This represents the *agreed upon starting point* for the technical > > > analysis of the T-MPLS requirements from the ITU-T and the MPLS > > > architecture to meet those requirements" > > > > > > So the quoted text in the draft is one of the assumptions. > > > > > > The fact that there are currently *two* OAM mechanisms (and not a > > > *single*), i.e. one for PW and one for LSP proves that the > assumption > > > was not correct. > > > > I'm sorry, I don't understand your logic. You seem to be saying that > > the fact that two solutions have been designed proves that the > > assumption > > that a single solution is possible was false. That doesn't follow at > > all. The engineering profession has a long history of producing > > multiple > > solutions where a single one was possible, and this seems to be just > > another such case. > > > > This isn't news. I quote from RFC 1958 (June 1996): > > > > " 3.2 If there are several ways of doing the same thing, choose one. > > If a previous design, in the Internet context or elsewhere, has > > successfully solved the same problem, choose the same solution > > unless > > there is a good technical reason not to. Duplication of the same > > protocol functionality should be avoided as far as possible, > without > > of course using this argument to reject improvements." > > > > Brian > > _______________________________________________ > > Ietf mailing list > > [email protected] > > https://www.ietf.org/mailman/listinfo/ietf > _______________________________________________ > Ietf mailing list > [email protected] > https://www.ietf.org/mailman/listinfo/ietf _______________________________________________ Ietf mailing list [email protected] https://www.ietf.org/mailman/listinfo/ietf
