On Sat, Sep 21, 2019 at 10:02 AM Voyer, Daniel <[email protected]> wrote: > > Hi Joel, > > Sent from my mobile > > > On Sep 21, 2019, at 00:54, Joel M. Halpern <[email protected]> wrote: > > > > I see where the draft defines a set of constraints. > > The constraint that there be no other extension headers is a fairly drastic > > constraint, which would seem a cause for concern. > > > > Putting that aside however, the draft does not seem to provide any > > explanation for why insertion rather than additional encapsulation is used. > > Particularly given the assumption that the MTU is large enough, it seems > > the encapsulation could be used for all insertion cases. > > > DV: correct, you can use encapsulations but at the cost of 40bytes overhead. > Running an operators backbone, with a widespread among of use cases, you need > those bytes..
Daniel, The overhead difference is more like 24 bytes since the destination IP address would need to be in the SID list in insertion case. The source address in encapsulation is useful to provide proper attribution. In any case, the argument that overhead matters would be much more convincing if the segment routing header itself was sparing in overhead (carrying a list of 16 byte IPv6 addresses is a lot of overhead). Tom > > > Yours, > > Joel > Regards > Dan > > > >> On 9/21/2019 12:34 AM, Darren Dukes (ddukes) wrote: > >> Hello everyone, we’ve just submitted an updated draft that explains why > >> SRH insertion is performed in an SR domain, how it is accomplished and why > >> it is safe within the SR domain. > >> The authors look forward to your comments and suggestions on how to > >> improve this document. > >> Thanks! > >> Darren (on behalf of the authors) > >>> Begin forwarded message: > >>> > >>> *From: *<[email protected] <mailto:[email protected]>> > >>> *Subject: **New Version Notification for > >>> draft-voyer-6man-extension-header-insertion-07.txt* > >>> *Date: *September 21, 2019 at 12:20:13 AM EDT > >>> > >>> > >>> A new version of I-D, draft-voyer-6man-extension-header-insertion-07.txt > >>> has been successfully submitted by Darren Dukes and posted to the > >>> IETF repository. > >>> > >>> Name:draft-voyer-6man-extension-header-insertion > >>> Revision:07 > >>> Title:Insertion of IPv6 Segment Routing Headers in a Controlled Domain > >>> Document date:2019-09-20 > >>> Group:Individual Submission > >>> Pages:13 > >>> URL: > >>> https://www.ietf.org/internet-drafts/draft-voyer-6man-extension-header-insertion-07.txt > >>> Status: > >>> https://datatracker.ietf.org/doc/draft-voyer-6man-extension-header-insertion/ > >>> Htmlized: > >>> https://tools.ietf.org/html/draft-voyer-6man-extension-header-insertion-07 > >>> Htmlized: > >>> https://datatracker.ietf.org/doc/html/draft-voyer-6man-extension-header-insertion > >>> Diff: > >>> https://www.ietf.org/rfcdiff?url2=draft-voyer-6man-extension-header-insertion-07 > >>> > >>> Abstract: > >>> Traffic traversing an SR domain is encapsulated in an outer IPv6 > >>> header for its journey through the SR domain. > >>> > >>> To implement transport services strictly within the SR domain, the SR > >>> domain may require insertion or removal of an SRH after the outer > >>> IPv6 header of the SR domain. Any segment within the SRH is strictly > >>> contained within the SR domain. > >>> > >>> The SR domain always preserves the end-to-end integrity of traffic > >>> traversing it. No extension header is manipulated, inserted or > >>> removed from an inner transported packet. The packet leaving the SR > >>> domain is exactly the same (except for the hop-limit update) as the > >>> packet entering the SR domain. > >>> > >>> The SR domain is designed with link MTU sufficiently greater than the > >>> MTU at the ingress edge of the SR domain. > >>> > >>> > >>> > >>> > >>> > >>> Please note that it may take a couple of minutes from the time of > >>> submission > >>> until the htmlized version and diff are available at tools.ietf.org > >>> <http://tools.ietf.org>. > >>> > >>> The IETF Secretariat > >>> > >> -------------------------------------------------------------------- > >> IETF IPv6 working group mailing list > >> [email protected] > >> Administrative Requests: https://www.ietf.org/mailman/listinfo/ipv6 > >> -------------------------------------------------------------------- > > > > -------------------------------------------------------------------- > > IETF IPv6 working group mailing list > > [email protected] > > Administrative Requests: https://www.ietf.org/mailman/listinfo/ipv6 > > -------------------------------------------------------------------- > > ------------------------------------------------------------------------------ > > External Email: Please use caution when opening links and attachments / > > Courriel externe: Soyez prudent avec les liens et documents joints > -------------------------------------------------------------------- > IETF IPv6 working group mailing list > [email protected] > Administrative Requests: https://www.ietf.org/mailman/listinfo/ipv6 > -------------------------------------------------------------------- _______________________________________________ spring mailing list [email protected] https://www.ietf.org/mailman/listinfo/spring
