Hi Stéphane, Of course, that type of request would only make sense when the PCE knows about supported types. Static configuration could allow that, but the update that Jon is going to include in the I-D allows the PCE to be aware of the supported capabilities by the PCC.
Anyway, I am fine with leaving that open for the future. I just want to make sure that we have consensus on the exact scope of the document before we freeze it. Thanks for the feedback, Julien Nov. 16, 2017 - stephane.litkow...@orange.com: > Hi Julien, > >> Over a PCEP session supporting multiple types, we do not have a mean to send >> a PCReq leaving the type selection to the PCE (no TLV implying type 0). > > I do not see the use case here. > In addition, I'm not sure that the PCE always know what are the setup types > actively supported by the PCC. As a consequence it may pick one which is not > supported and the LSP setup will fail. For SR, the PCE may know it through > the SR cap, but for RSVP, can the PCE deduce it from another information ? > > > Brgds, > > > -----Original Message----- > From: Julien Meuric [mailto:julien.meu...@orange.com] > Sent: Thursday, November 16, 2017 17:28 > > Hi, > > Glad to see we are converging. To make sure we are on the same page (solution > (2) referring to a shortcut), the conclusion is that, as soon as PST is not 0 > (i.e. RSVP-TE), we always include the PST TLV in PCReq, PCRep, PCUpd, PCRpt > and PCInitiate: is that right? > > This leads me to another question. Over a PCEP session supporting multiple > types, we do not have a mean to send a PCReq leaving the type selection to > the PCE (no TLV implying type 0). Do we consider a mean to support that? > (Could be 0xFF or a flag from the "Reserved" field.) > > Thanks, > > Julien > > > Nov. 16, 2017 - jonathan.hardw...@metaswitch.com: >> >> Hi Stephane >> >> >> >> OK, let's go with solution (2). That is, if the PATH-SETUP-TYPE is >> not present in a message, then it unambiguously means that the path >> setup type is RSVP-TE. Then implementations don't have to try to >> infer the path setup type from other objects or previous messages. >> >> >> >> I am revising draft-ietf-pce-lsp-setup-type at the moment to address >> an earlier comment from Julien, so I will include this clarification >> in the next revision. >> >> >> >> Thanks for the input! >> >> Cheers >> >> Jon >> >> >> >> >> >> *From:*stephane.litkow...@orange.com >> [mailto:stephane.litkow...@orange.com] >> *Sent:* 15 November 2017 13:52 >> >> >> >> Hi Jon, >> >> >> >> Thanks for your feedback. >> >> I see two possibilities here. >> >> 1. When the PATH-SETUP-TYPE is not present in a PCUpd, it should be >> inferred from the latest one received (in a PCInitiate or in a >> PCUpd). When initiating an LSP, the PCInitiate contains the PST to >> let the PCC know about the path type. Then, it can be omitted in >> further PCUpd except when the PCE wants to change the path type. >> At that time, it sends a PCUpd with a new PATH-SETUP-TYPE value >> and then it does not need to include it in further updates until >> the PCE needs to change it again. >> 2. We mandate the PCE to put the PATH-SETUP-TYPE in all PCUpd. >> >> >> >> IMO, solution 2) is easier for implementations and operation. >> >> >> >> Brgd, >> >> >> >> Stephane >> >> >> >> >> >> *From:*Jonathan Hardwick [mailto:jonathan.hardw...@metaswitch.com] >> *Sent:* Wednesday, November 15, 2017 09:28 >> *To:* LITKOWSKI Stephane OBS/OINIS; pce@ietf.org <mailto:pce@ietf.org> >> *Subject:* RE: Clarifications on PST handling in >> draft-ietf-pce-lsp-setup-type & draft-ietf-pce-segment-routing >> >> >> >> I think it should be acceptable for the PCUpd not to include the >> PATH-SETUP-TYPE, with the implication that there is no change to the >> path type. >> >> >> >> Although I'm not convinced it would be a good idea operationally, I >> don't think there's any need to prevent the path type changing on the >> PCUpd, if an explicit PATH-SETUP-TYPE is given. That is, >> draft-ietf-pce-lsp-setup-type, as a base draft, should allow that >> flexibility. A given device may choose not to allow that, of course. >> >> >> >> Does that sound reasonable? >> >> Cheers >> >> Jon >> >> >> >> >> >> *From:*Pce [mailto:pce-boun...@ietf.org] *On Behalf Of >> *stephane.litkow...@orange.com <mailto:stephane.litkow...@orange.com> >> *Sent:* 14 November 2017 00:38 >> *To:* pce@ietf.org <mailto:pce@ietf.org> >> *Subject:* [Pce] Clarifications on PST handling in >> draft-ietf-pce-lsp-setup-type & draft-ietf-pce-segment-routing >> >> >> >> Hi WG, >> >> >> >> I'm facing an interop issue between two PCEP implementations. >> >> PCE from vendor1 sends the PCInitiate for an SRTE LSP using the PST=1 >> in the SRP Object. >> >> PCC from vendor2 handles it correctly and delegates the LSP to the PCE >> using PST=1. >> >> When the PCE sends a PCUpdate message, it does not set the PST TLV in >> the SRP Object. >> >> The PCC rejects the PCUpdate because of a bad ERO subobject type. It >> reads the PCUpdate as having PST type=0. >> >> >> >> Based on my reading of draft-ietf-pce-lsp-setup-type & >> draft-ietf-pce-segment-routing. >> >> PST draft tells that for the PCE Initiation case, the PCE MAY include >> the PST if the message does not ave any other means of indicating the >> path setup type. SR draft tells "In order to setup an SR-TE LSP using >> SR, RP or SRP object MUST include PATH-SETUP-TYPE TLV". Unfortunately >> it does not specify explicitly in which message. From a reading >> perspective, we can understand from "In order to setup" that it >> applies to the PCInitiate message. But nothing tells about the >> PCUpdate message. >> >> However draft-ietf-pce-lsp-setup-type tells for the stateful PCE case >> that: "if the path setup type cannot be unambiguously inferred from >> ERO or any other object or TLV, PATH-SETUP-TYPE TLV MAY be used in >> PCRpt and PCUpd messages." >> >> In our case (PCE initiated) as the LSP has initially been setup >> through a PCInitiate message having the PST TLV, the PCC can infer >> that futher updates will use EROs associated with the same PST. >> >> >> >> Or do we allow to change the PST through PCUpdate messages which may >> require to always set the PST ? (moving from RSVP-TE to SR or the >> other way for a particular LSP) >> >> >> >> I would like to hear opinions of the WG on that problem ? >> >> >> >> Thanks, >> >> >> >> Brgds, >> >> >> >> >> >> Orange logo <http://www.orange.com/> >> >> >> >> *Stephane Litkowski * >> Network Architect >> Orange/SCE/EQUANT/OINIS/NET >> >> Orange Expert Future Networks >> >> phone: +33 2 23 *06* 49 83 >> <https://monsi.sso.francetelecom.fr/index.asp?target=http%3A%2F%2Fclicvoice.sso.francetelecom.fr%2FClicvoiceV2%2FToolBar.do%3Faction%3Ddefault%26rootservice%3DSIGNATURE%26to%3D+33%202%2023%2028%2049%2083%20> >> NEW ! >> mobile: +33 6 71 63 27 50 >> <https://monsi.sso.francetelecom.fr/index.asp?target=http%3A%2F%2Fclicvoice.sso.francetelecom.fr%2FClicvoiceV2%2FToolBar.do%3Faction%3Ddefault%26rootservice%3DSIGNATURE%26to%3D+33%206%2037%2086%2097%2052%20> >> NEW ! >> stephane.litkow...@orange.com <mailto:stephane.litkow...@orange.com> >> >> >> >> ______________________________________________________________________ >> ___________________________________________________ >> >> 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. 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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 >> Pce@ietf.org >> https://www.ietf.org/mailman/listinfo/pce > _______________________________________________ Pce mailing list Pce@ietf.org https://www.ietf.org/mailman/listinfo/pce
