Hi Ahmed and Authors, thank you for the update on the evolution of this work. I've read the latest version and have several questions. I greatly appreciate your kind consideration:
- As I understand it, the motivation for this work is the perceived overhead of some on-path telemetry methods: The overhead [of Path Tracing] is lower than [INT], [RFC9197], [I-D.song-opsawg-ifit-framework], and [I-D.kumar-ippm-ifa]. I find that statement too general and, as a result, not technically accurate. Both INT and IOAM support not only "in-packet" method of collecting and transporting generated on a node operational state and telemetry information, but also a mode (e.g., RFC 9326 IOAM Direct Expor <https://datatracker.ietf.org/doc/rfc9326/>t) in which such information is exported according to a local policy, e.g., using IPFIX or another management bus. If my understanding is correct, what could be the benefit of standardizing the Path Tracing? - Also, while comparing the network efficiency of an on-path telemetry methods, how, in the authors opinion, the density and informational reachness of the Path Tracing can be compared with the HPCC++ proposal <https://datatracker.ietf.org/doc/html/draft-miao-iccrg-hpccplus-01>? - The document requires that all nodes use a clock synchronization mechanism. Do you see a need to specify the quality of clock synchronization in an RT domain? - Upon finishing reading the draft, I find myself a bit surprised that it does not reference RFC 9341 <https://datatracker.ietf.org/doc/rfc9341/> Alternate-Marking Method. What are the authors thoughts about the AMM compared to RT? Regards, Greg On Wed, Oct 25, 2023 at 5:20 AM Ahmed Abdelsalam (ahabdels) <ahabdels= 40cisco....@dmarc.ietf.org> wrote: > Dear SPRING WG, > > > > We have submitted a new revision of draft-filsfils-spring-path-tracing. > > > > The previous revisions of the draft defined an SRH TLV and an IPv6 > Hop-by-Hop Option for Path Tracing. > > Based on received feedback we have replaced the SRH TLV with an IPv6 > Destination Option. > > > > The draft was last presented at IETF 113. The Hop-by-Hop option has > running-code across 5 different ASICs from different vendors (all > implementations are at linerate); in addition to the FD.io VPP and Linux > Kernel opensource implementations. More info in Section 5 of the draft. > > > > We look forward to the WG review and feedback. > > > > Thanks > > Ahmed > > > > *From: *internet-dra...@ietf.org <internet-dra...@ietf.org> > *Date: *Monday, 23 October 2023 at 17:56 > *To: *Ahmed Abdelsalam (ahabdels) <ahabd...@cisco.com>, Amit Dhamija < > am...@arrcus.com>, cf(mailer list) <c...@cisco.com>, Dhamija < > am...@arrcus.com>, Mark Yufit <mark.yu...@broadcom.com>, Mike Valentine < > michael.j.valent...@gs.com>, Pablo Camarillo (pcamaril) < > pcama...@cisco.com>, Pablo Camarillo (pcamaril) <pcama...@cisco.com>, > Satoru Matsushima <satoru.matsush...@g.softbank.co.jp>, Thomas Graf < > thomas.g...@swisscom.com>, Yuanchao Su <yitai....@alibaba-inc.com> > *Subject: *New Version Notification for > draft-filsfils-spring-path-tracing-05.txt > > A new version of Internet-Draft draft-filsfils-spring-path-tracing-05.txt > has > been successfully submitted by Ahmed Abdelsalam and posted to the > IETF repository. > > Name: draft-filsfils-spring-path-tracing > Revision: 05 > Title: Path Tracing in SRv6 networks > Date: 2023-10-23 > Group: Individual Submission > Pages: 18 > URL: > https://www.ietf.org/archive/id/draft-filsfils-spring-path-tracing-05.txt > Status: > https://datatracker.ietf.org/doc/draft-filsfils-spring-path-tracing/ > HTMLized: > https://datatracker.ietf.org/doc/html/draft-filsfils-spring-path-tracing > Diff: > https://author-tools.ietf.org/iddiff?url2=draft-filsfils-spring-path-tracing-05 > > Abstract: > > Path Tracing provides a record of the packet path as a sequence of > interface ids. In addition, it provides a record of end-to-end > delay, per-hop delay, and load on each egress interface along the > packet delivery path. > > Path Tracing allows to trace 14 hops with only a 40-bytes IPv6 Hop- > by-Hop extension header. > > Path Tracing supports fine grained timestamp. It has been designed > for linerate hardware implementation in the base pipeline. > > > > The IETF Secretariat > > _______________________________________________ > spring mailing list > spring@ietf.org > https://www.ietf.org/mailman/listinfo/spring >
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