Actually, since I wrote this: > 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.
I read this in draft-ietf-pce-lsp-setup-type: > The absence of the PATH-SETUP-TYPE TLV is equivalent to an PATH-SETUP-TYPE > TLV with an PST value of 0. What it doesn't say, but I think it means to say, is "... unless there is some other way to infer the path setup type from the message." So, if we follow my suggestion below, we would have to make it explicit that the path setup type for a PCUpd can be inferred from the current path setup type of the LSP (unless it is given explicitly), which is a change to draft-ietf-pce-lsp-setup-type. Does anyone else have an opinion on this? Thanks Jon From: Pce [mailto:pce-boun...@ietf.org] On Behalf Of Jonathan Hardwick Sent: 15 November 2017 09:28 To: stephane.litkow...@orange.com; pce@ietf.org Subject: Re: [Pce] 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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