Re: [Pce] Mail regarding draft-ietf-pce-pcep

["Samuel Sidor (ssidor)" <[e-mail]>]

Hi Pavan,

Is it possible to specify usecase a bit?

I’m not against allowing Vendor Info object in OPEN message, but I personally tend to agree with Dhruv’s explanation. In general, PCEP open message is supposed to exchange/negotiate various capabilities of PCEP peers, timer values, path-setup-types,… but all of them seems to be related to Open object, so vendor TLV seems to be sufficient for something like that.

In general, I can see benefit in using PCEP object over PCEP TLV (on top of logical association with underlaying object) in already defined flags in object header (P/I flags), which can help if you want to mark that object as mandatory/optional while TLV is always optional and can be ignored during parsing. In case of Vendor Info object, I don’t see good reason to mark it as mandatory, so flags are not adding any extra value. If you will mark vendor object as mandatory, then you will restrict processing of PCEP messages for specific LSPs to specific vendor only (logical assumption is that other vendors will not be able to process vendor object from other vendors), other vendors will have to reject it (if you want to do that, then you don’t need any standardization at all as you can use any private format).

So is there really any reason to use vendor info object instead of vendor TLV, which should be already allowed?

For argument about consistency – would it be really consistent even after that change? My understanding (but others can correct me) that TLVs can be included in a lot of PCEP objects (still probably not all as some objects are specifying explicitly that optional TLVs can be included, but some PCEP objects have fixed length) and all PCEP messages, where PCEP objects with optional TLVs can be included. But including any PCEP object MUST be explicitly allowed - including potential expected ordering of objects in that PCEP message (considering draft-dhody-pce-pcep-object-order).

Thanks,
Samuel

From: Vishnu Pavan Beeram <[e-mail]>
Sent: Wednesday, August 2, 2023 7:01 PM
To: Dhruv Dhody <[e-mail]>
Cc: Dhruv Dhody <[e-mail]>; Marcel Reuter (External) <[e-mail]>; [e-mail]; [e-mail]
Subject: Re: [Pce] Mail regarding draft-ietf-pce-pcep

I'm asking for the usage of the VENDOR_INFORMATION object to be allowed in the OPEN message (and not in notification, close and any other message where it is not already included). I would let the WG decide if it needs to be part of draft-ietf-pce-stateful-pce-vendor (case can be made to include it) or be discussed separately.

Regards,
-Pavan

On Wed, Aug 2, 2023 at 9:45 PM Dhruv Dhody <[e-mail]<mailto:[e-mail]>> wrote:
Hi Pavan,

In my personal opinion, the vendor TLV makes sense when the TLV is associated with an existing PCEP Object (and it allows optional TLV) and the vendor Object for something new! I would mostly consider anything sent in Open message to be related to existing OPEN object :)

Just to be clear, do you want this for OPEN message only or ALL PCEP messages (that would additionally include notification and close message as well)? If we go this route, we may need to change the name of the draft as it is no longer just stateful!

Thanks!
Dhruv (no hats)






On Wed, Aug 2, 2023 at 10:19 AM Vishnu Pavan Beeram <[e-mail]<mailto:[e-mail]>> wrote:
Please see inline..

On Wed, Aug 2, 2023 at 7:19 PM Dhruv Dhody <[e-mail]<mailto:[e-mail]>> wrote:
Hi Pavan,

On Wed, Aug 2, 2023 at 8:39 AM Vishnu Pavan Beeram <[e-mail]<mailto:[e-mail]>> wrote:
Marcel, Hi!
Thanks for bringing this to the list! I interpret the text in RFC5440 regarding "one OPEN object" to just mean that the Open Message cannot carry more than one "OPEN" object.

Dhruv, Hi!
I would propose updating draft-ietf-pce-stateful-pce-vendor to explicitly allow the use of the "VENDOR-INFORMATION" object in the Open message. For example, implementations may choose to carry "versioning" information in this object during the Open message exchange (this information may or may not have any impact on the establishment of the PCEP session). As you mentioned, carrying the "VENDOR-INFORMATION" TLV in the Open Object is already allowed. I don't see any good reason to preclude the use of the "VENDOR-INFORMATION" object in the Open message.


Hmm, with that reasoning do we need to do that for all PCEP messages?
[VPB] It is hard to envision what proprietary use-case someone may come up with. But allowing the VENDOR-INFORMATION usage in Open message along with PCReq, PCReply, PCRpt, PCUpd and PCInitiate messages seems reasonable to me.

Also, is there anything that cannot be achieved via the TLV, and you would need the Object in the Open message case? Just wondering...
[VPB] You can achieve everything by using just the Object or just the TLV (this is true for other messages as well). I'm advocating a consistent semantic -- allow for the use of both VENDOR-INFORMATION object and TLV in all the aforementioned messages.


Thanks!
Dhruv



Regards,
-Pavan

On Wed, Aug 2, 2023 at 6:51 PM Dhruv Dhody <[e-mail]<mailto:[e-mail]>> wrote:
Hi Marcel,

Welcome, please consider joining the PCE mailing list so that we don't have to manually approve your email to the list - https://www.ietf.org/mailman/listinfo/pce

See inline...

On Wed, Aug 2, 2023 at 8:11 AM Marcel Reuter (External) <[e-mail]<mailto:[e-mail]>> wrote:
Aloha,

dear colleagues!

This is my very first E-mail ever to IETF.
So please forgive me, if I dont follow all rules.

I have a question about the RFC5440
Section 6-2


https://www.rfc-editor.org/rfc/rfc5440.html#section-6.2

The RFC says:

6.2.  Open Message

...
   The format of an Open message is as follows:

   <Open Message>::= <Common Header>
                     <OPEN>
 The Open message MUST contain exactly one OPEN object (see
   Section 7.3).


Unfortunately, Im not very firm in BNF syntax
My question here is to  understand the last sentence.

Is it allowed, just from a pure protocol standpoint,
to send in the open message
1 (one) open object
AND also
1(one)  VENDOR-INFORMATION object with the P-flag not set?


We are an operator and using PCE from one vendor and router from different other vendors and have currently some interesting discussing about that topic

RFC 7470 (https://datatracker.ietf.org/doc/rfc7470/) added a VENDOR-INFORMATION Object for PCReq and PCRep messages!
https://datatracker.ietf.org/doc/draft-ietf-pce-stateful-pce-vendor/ addes the same for PCRpt and PCUpd messages!

We have not specified the use of the Object within the Open message!
If there is a need to carry vendor specific information, then using the VENDOR-INFORMATION-TLV within the Open object is allowed.

In case they have a need for the object within the Open message, please provide a usecase and perhaps it can be added in the draft!

Hope this helps!

Thanks!
Dhruv



Thanks a lot
Marcel

:-)


VG
Marcel Reuter

--
Marcel Reuter
Im Auftrag der Telefónica Germany GmbH & Co. OHG
Überseering 33a
22297 Hamburg

[e-mail]<mailto:[e-mail]>

________________________________

Este mensaje y sus adjuntos se dirigen exclusivamente a su destinatario, puede contener información privilegiada o confidencial y es para uso exclusivo de la persona o entidad de destino. Si no es usted. el destinatario indicado, queda notificado de que la lectura, utilización, divulgación y/o copia sin autorización puede estar prohibida en virtud de la legislación vigente. Si ha recibido este mensaje por error, le rogamos que nos lo comunique inmediatamente por esta misma vía y proceda a su destrucción.

The information contained in this transmission is confidential and privileged information intended only for the use of the individual or entity named above. If the reader of this message is not the intended recipient, you are hereby notified that any dissemination, distribution or copying of this communication is strictly prohibited. If you have received this transmission in error, do not read it. Please immediately reply to the sender that you have received this communication in error and then delete it.

Esta mensagem e seus anexos se dirigem exclusivamente ao seu destinatário, pode conter informação privilegiada ou confidencial e é para uso exclusivo da pessoa ou entidade de destino. Se não é vossa senhoria o destinatário indicado, fica notificado de que a leitura, utilização, divulgação e/ou cópia sem autorização pode estar proibida em virtude da legislação vigente. Se recebeu esta mensagem por erro, rogamos-lhe que nos o comunique imediatamente por esta mesma via e proceda a sua destruição

_______________________________________________
Pce mailing list
[e-mail]<mailto:[e-mail]>
https://www.ietf.org/mailman/listinfo/pce
_______________________________________________
Pce mailing list
[e-mail]<mailto:[e-mail]>
https://www.ietf.org/mailman/listinfo/pce
_______________________________________________
Pce mailing list
[e-mail]<mailto:[e-mail]>
https://www.ietf.org/mailman/listinfo/pce