Hi Olivier, I believe what you are trying to achieve is:
1. Attach a Stitching Label to a Tunnel/Policy, similar to how a Binding Label points to a Tunnel/Policy. 2. Signal the presence of a Stitching Label in the path of a Tunnel/Policy. I believe that #1 can be achieved using the Binding Label TLV, by perhaps defining another Binding Type. And #2 can be achieved by adding another ERO/SR-ERO sub-object. I do not think it’s a good idea to use the RRO unless there is an actual RSVP RECORD_ROUTE being used. Thanks, Mike. From: Pce <[email protected]> On Behalf Of Stone, Andrew (Nokia - CA/Ottawa) Sent: Thursday, March 11, 2021 11:11 AM To: [email protected]; Dhruv Dhody <[email protected]> Cc: [email protected] Subject: Re: [Pce] Implementation option of draft-ietf-pce-stateful-interdomain-01.txt Hi Olivier, Thanks for pointing this out. I think the presentation slide wording might have been a bit stronger than what is currently written in the posted draft, as the text does not prohibit the use of RRO but rather acknowledge and document that there are implementations which skip inclusion of SR-RRO (Nokia implementation does send SR-RRO), so it documents how to handle this scenario on the PCE. The text indicates that SR-RRO may or may not be included, and if omitted the PCE is to fallback to treating the ERO “like” it was an RRO. https://datatracker.ietf.org/doc/html/draft-koldychev-pce-operational-03#section-6 A PCC MUST send an (possibly empty) ERO/SR-ERO/SRv6-ERO in the PCRpt message for every LSP. A PCC MAY send an SR-RRO/SRv6-RRO for an SR- TE/SRv6-TE LSP (respectively). A PCE SHOULD interpret the RRO/SR- RRO/SRv6-RRO as the actual path the LSP is taking but MAY interpret only the ERO/SR-ERO/SRv6-ERO as the actual path. In the absence of an RRO/SR-RRO/SRv6-RRO a PCE SHOULD interpret the ERO/SR-ERO/SRv6-ERO (respectively) as the actual path for the LSP. I think the potential interdomain stitching label case you point out and the S-Flag defined in RFC8664 mentioned by Dhruv during the meeting seem to be valid use cases where an SR-RRO would need to be included. Thanks! Andrew From: Pce <[email protected]<mailto:[email protected]>> on behalf of "[email protected]<mailto:[email protected]>" <[email protected]<mailto:[email protected]>> Organization: Orange Labs Date: Thursday, March 11, 2021 at 5:17 AM To: Dhruv Dhody <[email protected]<mailto:[email protected]>> Cc: "[email protected]<mailto:[email protected]>" <[email protected]<mailto:[email protected]>> Subject: Re: [Pce] Implementation option of draft-ietf-pce-stateful-interdomain-01.txt Hello Dhruv, all, Following the presentation done during the IETF meeting, please find the link to the presentation: https://datatracker.ietf.org/meeting/110/materials/slides-110-pce-32-inter-domain-00 I also not a major point to take into account following the presentation of draft PCEP Operational Clarification (draft-koldychev-pce-operational) see https://datatracker.ietf.org/doc/draft-koldychev-pce-operational/ and https://datatracker.ietf.org/meeting/110/materials/slides-110-pce-34-operational-clarification-00: => In this draft, authors propose to use SR-ERO/SRv6-ERO and to NOT use SR-RRO/SR-v6-RRO for Segment Routing. As a consequence for the stateful inter-domain draft, proposed option d1, d2 and d3 become invalid as it uses the RRO to convey the Stiching Label. Thus, only option d4 with a specific new sub-Object to convey the Stitching Label remains valid. As usual, comments are welcome. Regards Olivier Le 26/02/2021 à 05:35, Dhruv Dhody a écrit : Hi Olivier, Thanks for starting this thread. As a WG participant... On Tue, Feb 23, 2021 at 12:05 AM <[email protected]<mailto:[email protected]>> wrote: Dear all, According to the remark about implementation we got during the WG call for adoption, we would start a new thread to discuss this point. The goal isto prepare the discussion for next IETF meeting and reach a consensusin order to edit revision 2 of the draft. The stitching label principle requires at least a certain number of modifications in the current PCEP version: a) A new PCE Capability to announce the inter-domain behaviour b) A new PCE Association Group to associate the local paths identifier to the inter-domain identifier c) new PCEP Errors to manage the Stitching Label exchange d) A mechanism to convey the Stitching Label If there is no other choice than to reuse existing PCEP Objects by allocating new code points for modifications a-c,there is several options for point d, which we have tried to list below: d1) Use ERO and RRO in conjunction to new Path Setup code points as described in version 01 of the draft. It is the simplest implementation but as mention by Dhruv, each time a new path enforcement appear, a new PST code point must be allocated. For example, when Segment Routing v6 will be standardized, we must allocate a new Stitching label PST code point for SRv6. d2) Use ERO and ERO in conjunction to a new flag in LSP. Simple as for d1, but need to use the LSP Extended Flag draft as all LSP flags have been already allocated. d3) Same as d2 but find another place for the flag e.g. SRP or LSPA Object. d4) Define a new PCEP sub-Objet TLV within the LSP Object to convey the stitching label. This is more independent but need extra parsing from an implementation point of view. My preference would for d2 or d3 (in that order). LSP Extended Flag is adopted by the WG and is ready for prime-time use -- let's use it :) Authors of LSP Extended Flag are waiting for the draft blockade to be lifted to post the -00 WG I-D. Thanks! Dhruv Please, give us your opinion about these different options and don't hesitate to propose others. Regards Olivier on be-half of co-author's _________________________________________________________________________________________________________________________ Ce message et ses pieces jointes peuvent contenir des informations confidentielles ou privilegiees et ne doivent donc pas etre diffuses, exploites ou copies sans autorisation. Si vous avez recu ce message par erreur, veuillez le signaler a l'expediteur et le detruire ainsi que les pieces jointes. Les messages electroniques etant susceptibles d'alteration, Orange decline toute responsabilite si ce message a ete altere, deforme ou falsifie. Merci. This message and its attachments may contain confidential or privileged information that may be protected by law; they should not be distributed, used or copied without authorisation. If you have received this email in error, please notify the sender and delete this message and its attachments. As emails may be altered, Orange is not liable for messages that have been modified, changed or falsified. Thank you. _______________________________________________ Pce mailing list [email protected]<mailto:[email protected]> https://www.ietf.org/mailman/listinfo/pce -- [Orange logo]<http://www.orange.com/> Olivier Dugeon Orange Expert, Future Networks Open Source Referent Orange/IMT/OLN/WTC/IEE/iTeQ fixe : +33 2 96 07 28 80 mobile : +33 6 82 90 37 85 [email protected]<mailto:[email protected]> _________________________________________________________________________________________________________________________ Ce message et ses pieces jointes peuvent contenir des informations confidentielles ou privilegiees et ne doivent donc pas etre diffuses, exploites ou copies sans autorisation. Si vous avez recu ce message par erreur, veuillez le signaler a l'expediteur et le detruire ainsi que les pieces jointes. Les messages electroniques etant susceptibles d'alteration, Orange decline toute responsabilite si ce message a ete altere, deforme ou falsifie. Merci. This message and its attachments may contain confidential or privileged information that may be protected by law; they should not be distributed, used or copied without authorisation. If you have received this email in error, please notify the sender and delete this message and its attachments. As emails may be altered, Orange is not liable for messages that have been modified, changed or falsified. Thank you.
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