I see it. Thanks Les & Peter!
Gyan On Fri, Jul 23, 2021 at 12:34 PM Les Ginsberg (ginsberg) <ginsb...@cisco.com> wrote: > Gyan – > > > > This question has been clearly addressed by Peter in his most recent post: > > > > <snip> > > 2. Generic Metric is not something that must be defined as application > > independent, on the contrary, it's a value that is either assigned by > > operator or computed somehow. Advertising application specific values > > not only make sense, but would add value. TE metric is an example which > > is very close to Generic Metric and is supported in ASLA. > > <end snip> > > > > Please read his email for the complete response. > > > > Les > > > > *From:* Gyan Mishra <hayabusa...@gmail.com> > *Sent:* Friday, July 23, 2021 8:26 AM > *To:* Les Ginsberg (ginsberg) <ginsb...@cisco.com> > *Cc:* Acee Lindem (acee) <a...@cisco.com>; Peter Psenak (ppsenak) < > ppse...@cisco.com>; Ron Bonica <rbon...@juniper.net>; Shraddha Hegde < > shrad...@juniper.net>; draft-ietf-lsr-flex-algo-bw-con.auth...@ietf.org; > gregory.mir...@ztetx.com; lsr@ietf.org > *Subject:* Re: [Lsr] I-D Action: draft-ietf-lsr-flex-algo-bw-con-01.txt > > > > > > > > I believe the gap is whether or not the Generic metric is like maximum > bandwidth link attribute which is application independent and based on the > use case in this draft of the WG can be convinced that this use case is for > application independent. > > > > In RFC 8919 and RFC 8920 the normative language was chosen precisely for > that purpose so that on a case by case basis for a an link attribute to be > deemed ASLA or application independent. > > > > Kind Regards > > > > Gyan > > > > On Thu, Jul 22, 2021 at 3:44 PM Gyan Mishra <hayabusa...@gmail.com> wrote: > > > > As stated nicely by Les, the goal and intent of RFC 8919 and 8920 as > stated clearly was meant to fix a ambiguities related to cases where > multiple applications RSVP-TE, SR, Flex Algo making use of link attributes > by creating ASLA for a list of link attributes sub-tlv’s that existed at > time of writing the document, however moving forward that all new link > attributes defined MUST now be advertised using ASLA sub tlv. > > > > By not doing do you are perpetuating the problem all over again. > > > > The chairs and other in the WG would like to draw a line in the sand that > any new link attribute MUST be advertised using ASLA SUB-TLV encoding. > > > > RFC 8919 -Last paragraph in the introduction > > > > This document defines extensions that address these issues. Also, as > > evolution of use cases for link attributes can be expected to > > continue in the years to come, this document defines a solution that > > is easily extensible to the introduction of new applications and new > > use cases. > > > > RFC 8920- Last paragraph in the introduction > > > > This document defines extensions that address these issues. Also, as > > evolution of use cases for link attributes can be expected to > > continue in the years to come, this document defines a solution that > > is easily extensible for the introduction of new applications and new > > use cases. > > > > The key is the extensibility of RFC 8919 and RFC 8920 for all future link > attributes and not just the ones defined when the draft was written. > > > > Kind Regards > > > > Gyan > > > > > > > > > > > > > > On Thu, Jul 22, 2021 at 2:49 PM Les Ginsberg (ginsberg) <ginsberg= > 40cisco....@dmarc.ietf.org> wrote: > > Ron - > > With respect, it is hard to read your email without feeling that it is > disingenuous. > > But, let's cover the relevant points nonetheless. > > Point #1: > > > https://datatracker.ietf.org/doc/html/draft-ietf-lsr-flex-algo-17#section-12 > states: > > " Link attribute advertisements that are to be used during Flex- > Algorithm calculation MUST use the Application-Specific Link > Attribute (ASLA) advertisements defined in [RFC8919] or [RFC8920]..." > > As the new generic-metric is intended for use by flex-algo it needs to > conform to this normative statement. > > Point #2: > > RFC 8919 and 8920 were written to address ambiguities associated with the > use of multiple applications. > The Introduction sections of both documents discuss this in some detail. > > The clear intent is to make use of ASLA going forward - not to restrict > ASLA only to the set of link attributes defined at the time of the writing > of the RFCs. Failure to do so would reintroduce the same set of issues that > RFC 8919/8920 were written to address. > Your attempt to infer that because Generic-Metric was not defined at the > time that RFC 8919/8920 were written that the RFCs don’t apply to it makes > no sense. > ASLA is in fact a revision to the link attribute architecture and is meant > to be used going forward. > > The more appropriate question to ask is why we need to define a legacy > style sub-TLV for new link attributes? Ketan has made this point in his > post on this thread and I have sympathy with his position. > > We do understand that legacy applications such as RSVP-TE may continue to > be deployed in networks for some time to come. It is not reasonable to > expect that legacy application implementations will be updated to use ASLA, > which is why I do not object to defining a legacy style encoding for > Generic Metric if folks believe that legacy applications may be enhanced to > support new link attributes. > > I strongly disagree with your interpretation that ASLA is limited only to > the code points defined in RFC 8919/8920. > > Les > > > > -----Original Message----- > > From: Ron Bonica <rbonica=40juniper....@dmarc.ietf.org> > > Sent: Thursday, July 22, 2021 10:28 AM > > To: Acee Lindem (acee) <a...@cisco.com>; Les Ginsberg (ginsberg) > > <ginsb...@cisco.com>; Shraddha Hegde <shrad...@juniper.net>; > > gregory.mir...@ztetx.com; Peter Psenak (ppsenak) <ppse...@cisco.com>; > > lsr@ietf.org > > Cc: draft-ietf-lsr-flex-algo-bw-con.auth...@ietf.org > > Subject: RE: [Lsr] I-D Action: draft-ietf-lsr-flex-algo-bw-con-01.txt > > > > Acee, > > > > I don't think that draft-ietf-lsr-flex-algo-bw-con violates RFC 8919. > > > > Section 6.1 of RFC 8919 says: > > > > " New applications that future documents define to make use of the > > advertisements defined in this document MUST NOT make use of legacy > > advertisements. This simplifies deployment of new applications by > > eliminating the need to support multiple ways to advertise attributes > > for the new applications." > > > > Section 3 of RFC 8919 defines legacy advertisements. The definition of > legacy > > advertisements does not include new attributes such as > > generic metric. Therefore draft-ietf-lsr-flex-algo-bw-con does not > > violate RFC 8919 > > > > Relevant text from Section 3 of RFC 8919 is included below for > convenience. > > > > Ron > > > > > > RFC 8919, Section 3 > > --------------------------- > > 3. Legacy Advertisements > > > > > > Existing advertisements used in support of RSVP-TE include sub-TLVs > > for TLVs 22, 23, 25, 141, 222, and 223 and TLVs for Shared Risk Link > > Group (SRLG) advertisement. > > > > Sub-TLV values are defined in the "Sub-TLVs for TLVs 22, 23, 25, 141, > > 222, and 223" registry. > > > > TLVs are defined in the "TLV Codepoints Registry". > > > > 3.1. Legacy Sub-TLVs > > > > +======+====================================+ > > | Type | Description | > > +======+====================================+ > > | 3 | Administrative group (color) | > > +------+------------------------------------+ > > | 9 | Maximum link bandwidth | > > +------+------------------------------------+ > > | 10 | Maximum reservable link bandwidth | > > +------+------------------------------------+ > > | 11 | Unreserved bandwidth | > > +------+------------------------------------+ > > | 14 | Extended Administrative Group | > > +------+------------------------------------+ > > | 18 | TE Default Metric | > > +------+------------------------------------+ > > | 33 | Unidirectional Link Delay | > > +------+------------------------------------+ > > | 34 | Min/Max Unidirectional Link Delay | > > +------+------------------------------------+ > > | 35 | Unidirectional Delay Variation | > > +------+------------------------------------+ > > | 36 | Unidirectional Link Loss | > > +------+------------------------------------+ > > | 37 | Unidirectional Residual Bandwidth | > > +------+------------------------------------+ > > | 38 | Unidirectional Available Bandwidth | > > +------+------------------------------------+ > > | 39 | Unidirectional Utilized Bandwidth | > > +------+------------------------------------+ > > > > Table 1: Sub-TLVs for TLVs 22, 23, 25, > > 141, 222, and 223 > > > > > > > > Juniper Business Use Only > > > > -----Original Message----- > > From: Lsr <lsr-boun...@ietf.org> On Behalf Of Acee Lindem (acee) > > Sent: Tuesday, July 20, 2021 1:21 PM > > To: Les Ginsberg (ginsberg) <ginsberg=40cisco....@dmarc.ietf.org>; > > Shraddha Hegde <shrad...@juniper.net>; gregory.mir...@ztetx.com; > > ppsenak=40cisco....@dmarc.ietf.org; lsr@ietf.org > > Cc: draft-ietf-lsr-flex-algo-bw-con.auth...@ietf.org > > Subject: Re: [Lsr] I-D Action: draft-ietf-lsr-flex-algo-bw-con-01.txt > > > > [External Email. Be cautious of content] > > > > > > Speaking as WG member: > > > > I agree with Les. The Generic Metric MUST be advertised as an ASLA for > > usage in Flex Algorithm. Additionally, it may be advertised as a sub-TLV > in IS- > > IS link TLVs. However, the latter encoding really shouldn't be used for > new > > applications (at least that is my reading of RFC 8919). > > > > For OSPF, I'd certainly hope one wouldn't originate additional LSAs when > an > > ASLA can support the legacy applications with the ASLA mask. > > > > Thanks, > > Acee > > > > > _______________________________________________ > Lsr mailing list > Lsr@ietf.org > https://www.ietf.org/mailman/listinfo/lsr > > -- > > [image: Image removed by sender.] <http://www.verizon.com/> > > *Gyan Mishra* > > *Network Solutions Architect * > > *Email gyan.s.mis...@verizon.com <gyan.s.mis...@verizon.com>* > > *M 301 502-1347* > > > > -- > > [image: Image removed by sender.] <http://www.verizon.com/> > > *Gyan Mishra* > > *Network Solutions Architect * > > *Email gyan.s.mis...@verizon.com <gyan.s.mis...@verizon.com>* > > *M 301 502-1347* > > > -- <http://www.verizon.com/> *Gyan Mishra* *Network Solutions A**rchitect * *Email gyan.s.mis...@verizon.com <gyan.s.mis...@verizon.com>* *M 301 502-1347*
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