[mpls] Re: Working Group Last Call for draft-ietf-mpls-spring-lsp-ping-path-sid (was Re: Working Group Last Call on draft-xp-mpls-spring-lsp-ping-path-sid)

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Hi Greg,

I have to admit that we have different understandings on whether the PCEP and BGP documents must be listed as normative references.
Anyway, I find the discussion on PCEP and BGP encodings helpful for further clarifications in the related PCEP and BGP documents.
I noticed that the primary author is the same for draft-ietf-pce-sr-path-segment and draft-ietf-idr-sr-policy-path-segment, so I believe there is alignment between the two control protocols, in other words, I doubt there exist a fundamental problem with the BGP part. Please continue the discussion on BGP part.

Cheers,
Xiao Min

Original


From: GregMirsky <[e-mail]>
To: 肖敏10093570;
Cc: 熊泉00091065;[e-mail] <[e-mail]>;[e-mail] <[e-mail]>;[e-mail] <[e-mail]>;
Date: 2024年08月21日 10:32
Subject: Re: [mpls] Re: Working Group Last Call for draft-ietf-mpls-spring-lsp-ping-path-sid (was Re: Working Group Last Call on draft-xp-mpls-spring-lsp-ping-path-sid)




Hi Xiao Min,I will quote the IESG Statement: Normative and Informative References:


Within an RFC, references to other documents fall into two general categories: "normative" and "informative". Normative references specify documents that must be read to understand or implement the technology in the new RFC, or whose technology must be present for the technology in the new RFC to work. An informative reference is not normative; rather, it only provides additional information. For example, an informative reference might provide background or historical information. Informative references are not required to implement the technology in the RFC. 

Note 1: Even references that are relevant only for optional features must be classified as normative if they meet the above conditions for normative references. 



I believe that PCE and BGP documents referenced in the relationship to the validation process must be normative, not informative, even if that will cause dependency and may delay the publication of this draft.

Furthermore, I believe that there exist a fundamental problem with BGP SR Policy as explained in my discussion with Yao Liu. I believe that cases when an endpoint of an BGP SR Policy are not informaed of the BGP SR Policy must be discussed by the MPLS and IDR WGs and reflected in this draft accordingly.

Regards,
Greg




On Tue, Aug 20, 2024 at 7:02 PM <[e-mail]> wrote:


Hi Greg,

Glad to know Quan's responses satisfactorily answer your questions. Thanks to Quan!
Now it seems your concern goes back to that you think PCEP and BGP specs must be listed as normative references.
I disagree with that and I'd like to repeat the reasons as below.
* This is an LSP Ping document and introducing PCEP and BGP encoding details is overspecified.
* RFC 9256 and 9545 provide enough basis to this document, how the necessary fields are encoded in PCEP and BGP won't affect how the interoperable LSP Ping works.
* Waiting for the publications of PCEP and BGP specs won't bring much value to this document.

Best Regards,
Xiao Min

Original

From: GregMirsky <[e-mail]>
To: 熊泉00091065;
Cc: [e-mail] <[e-mail]>;[e-mail] <[e-mail]>;[e-mail] <[e-mail]>;
Date: 2024年08月21日 06:14
Subject: [mpls] Re: Working Group Last Call for draft-ietf-mpls-spring-lsp-ping-path-sid (was Re: Working Group Last Call on draft-xp-mpls-spring-lsp-ping-path-sid)

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Hi Quan,thank you for your patience and the detailed response, it is clear to me now how the PCE configures an SR Policy at its headend and endpoint. Considering that in-depth understanding of PCE is critical for producing an interoperable implementation of this draft, I strongly believe that RFC 8697, draft-ietf-pce-segment-routing-policy-cp, and draft-ietf-pce-sr-path-segment must be listed as the Normative references.

Regards,
Greg






On Tue, Aug 20, 2024 at 1:39 AM <[e-mail]> wrote:



Hi Greg,

From my view, as shown in figure 3,4 and 5 draft-ietf-pce-sr-path-segment, the PCE will send PCInitiate message to Egress PCC. And the  PCInitiate message will not only include the PATH-SEGMENT TLV in the LSP object, but also carry the association object. As specified in RFC8697 section 6.3.1 [1], the PCInitiate message is as following shown.
<PCE-initiated-lsp-instantiation> ::= <SRP> <LSP> [<END-POINTS>] <ERO> [<association-list>] [<attribute-list>]
Where:
<association-list> ::= <ASSOCIATION> [<association-list>]
[1]https://www.rfc-editor.org/rfc/rfc8697.html#name-stateful-pcep-messages 

From this message, the LSP object will include PATH-SEGMENT TLV and the ASSOCIATION object which is related to the SR policy will carry the assication source (headend). 
Hope that will help! Thanks!

Best,
Quan





From: GregMirsky <[e-mail]>
To: 熊泉00091065;
Cc: [e-mail] <[e-mail]>;[e-mail] <[e-mail]>;[e-mail] <[e-mail]>;
Date: 2024年08月20日 11:39
Subject: Re: Working Group Last Call for draft-ietf-mpls-spring-lsp-ping-path-sid (was Re: Working Group Last Call on draft-xp-mpls-spring-lsp-ping-path-sid)



Hi Quan,thank you for clarifying that to me. I hope that you can help me in understanding how the ASSOCIATION object of SR Policy type is related to figures 3, 4, and 5 draft-ietf-pce-sr-path-segment. AFAICS, only flow of PATH-SEGMENT TLV from PCEP to PCC in both headend and endpoint of the SR Policy is reflected in these figures. At which phase the ASSOCIATION object is communicated to the endpoint?

Regards,
Greg





On Mon, Aug 19, 2024 at 7:59 PM <[e-mail]> wrote:


Hi Greg,

Thanks for your questions!

The identity of the SR Policy's Headend has been proposed in the PCE-related specifications. As per draft-ietf-pce-segment-routing-policy-cp section 4.1 [1], the headend is encoded in the 'Association Source' field in the ASSOCIATION object. The color and endpoint are encoded as part of the Extended Association ID TLV.

[1] https://www.ietf.org/archive/id/draft-ietf-pce-segment-routing-policy-cp-17.html#name-association-parameters

Thanks,
Quan




[mpls] Re: Working Group Last Call for draft-ietf-mpls-spring-lsp-ping-path-sid (was Re: Working Group Last Call on draft-xp-mpls-spring-lsp-ping-path-sid)
Greg Mirsky <[e-mail]> Mon, 19 August 2024 23:32 UTCShow header
Dear All, I paused to arrange my concerns about the draft and put them in front of you more clearly. Below is what it came to: - The purpose of Target FEC Stack TLV in LSP echo request, as I understand it, is to verify consistency between the data plane and the control plane view of the data plane. That is why the sender of an echo request with Target FEC Stack TLV includes a sub-TLV that, from the sender's perspective, sufficiently represents the control plane information associated with the verifiable label. - If the above is correct, I move to the next point. All sub-TLVs in the Target FEC Stack TLV must be validated. The validation process is sub-TLV-specific. This draft defines the validation process, using PCEP as an example, as follows: * Validate that the signaled headend, color, end-point, originator ASN, originator address, and discriminator defined in [I-D.ietf-pce-segment-routing-policy-cp] and [I-D.ietf-pce-sr-path-segment], for the PSID, matches with the corresponding fields in the received SR Candidate Path's PSID sub-TLV. Now, my question: What is meant as validation of Headend? - The reason for my question above is that I cannot find that the identity of the Headend is included in PCEP constructs defined for the configuration of an SR Policy. Am I missing something in PCE-related specifications, or must they be enhanced to convey the identity of the SR Policy's Headend? - There's a possible way to use information already available in the IP-encapsulated echo request message and source IP address. Personally, I would consider such a check a security measure rather than validation, but how would validation work if no IP/UDP encapsulation of the echo request is used? I hope that I made my concern more evident now. I welcome your comments and questions. Regards, Greg On Tue, Aug 6, 2024 at 10:13 AM Tarek Saad <[e-mail]> wrote: > Hi WG, > > > > I am correcting a mistake to reference to the WG adopted draft (as opposed > to the individual draft for the same document). Sorry for the confusion. > > > > Regards, > > Tarek > > > > *From: *Tarek Saad <[e-mail]>> > *Date: *Tuesday, August 6, 2024 at 9:53 AM > *To: *[e-mail] <[e-mail]>> *Cc: *MPLS Working Chairs <[e-mail]>, > [e-mail] < > [e-mail]>> *Subject: *Working Group Last Call on > draft-xp-mpls-spring-lsp-ping-path-sid > > Dear WG, > > > > This email starts a two-week working group last call for > draft-ietf-mpls-spring-lsp-ping-path-sid > <https://datatracker.ietf.org/doc/draft-ietf-mpls-spring-lsp-ping-path-sid/> > . > > > > Please indicate your support or concern for this draft. If you are opposed > to the progression of the draft to RFC, please articulate your concern. If > you support it, please indicate that you have read the latest version, and > it is ready for publication in your opinion. As always, review comments and > nits are most welcome. > > > > Please send your comments to the mpls wg mailing list ([e-mail]) > > If necessary, comments may be sent unidirectional to the WG chairs. > > > > Note, currently there are no IPR disclosures > <https://datatracker.ietf.org/ipr/search/?submit=draft&id=draft-xp-mpls-spring-lsp-ping-path-sid> > against this document. > > > > This poll runs until August 20, 2024. > > > > Thank you, > > Tarek (for the MPLS WG co-chairs) > > > _______________________________________________ > mpls mailing list -- [e-mail]> To unsubscribe send an email to [e-mail]>

[mpls] Working Group Last Call on draft-xp-mpls-s…  Tarek Saad

[mpls] Re: Working Group Last Call on draft-xp-mp…  Greg Mirsky

[mpls] Working Group Last Call for draft-ietf-mpl…  Tarek Saad

[mpls] Re: Working Group Last Call for draft-ietf…  Greg Mirsky

[mpls] Re: Working Group Last Call for draft-ietf…  xiao.min2

[mpls] Re: Working Group Last Call for draft-ietf…  Greg Mirsky

[mpls] Re: Working Group Last Call for draft-ietf…  xiao.min2

[mpls] Re: Working Group Last Call for draft-ietf…  Greg Mirsky

[mpls] Re: Working Group Last Call for draft-ietf…  xiao.min2

[mpls] Re: Working Group Last Call for draft-ietf…  Greg Mirsky

[mpls] Re: Working Group Last Call for draft-ietf…  xiao.min2

[mpls] Re: Working Group Last Call for draft-ietf…  xiao.min2

[mpls] Re: Working Group Last Call for draft-ietf…  peng.shaofu

[mpls] Re: Working Group Last Call for draft-ietf…  Rakesh Gandhi

[mpls] Re: Working Group Last Call for draft-ietf…  Liyan Gong

[mpls] Re: Working Group Last Call for draft-ietf…  Greg Mirsky

[mpls] Re: Working Group Last Call for draft-ietf…  Greg Mirsky

[mpls] Re: Working Group Last Call on draft-xp-mp…  高星(联通集团本部)