Re: [Pce] [PCE]: Draft-ietf-pce-sid-algo: Prefer Intra vs Inter-domain

Hi Samuel,

I stand corrected, how did i forget the long debate on metric-type and FAD
:)
What I wanted to convey was if you need to signal this, do look for
mechanisms that already exist!

Thanks!
Dhruv

On Tue, Sep 19, 2023 at 12:59 PM Samuel Sidor (ssidor) <ssidor=
40cisco.com@dmarc.ietf.org> wrote:

> Hi Dhruv,
>
>
>
> In case of path-computation done by PCE based on content of FAD (probably
> vast majority of cases), optimization metric will be specified in FAD, so
> it will not be possible to optimize based on other metric type on top of
> that.
>
>
>
> For original question:
>
>
>
> I agree with PSF – it would be probably too complex to try to define such
> behavior in the draft. On top of that, such requirement can potentially
> come for non-Flex-algo paths as well.
>
>
>
> I can still imagine achieving something like that for example with 2
> candidate-paths:
>
>    - 1st CP (preferred) which will be limited to intra-domain paths using
>    some constraints
>    - 2nd CP which will not have any restrictions and which can be used in
>    case of no intra-domain path
>
>
>
> That can be achieved with metric bound of metric pointed out by Dhruv,
> affinity,… set for 1st CP. Theoretically same thing can be achieved by
> setting MSD bound in 1st CP as with Flex-algo path-computation will
> probably result in just one SID anyway (Flex-algo SID of destination) – at
> least if other constraints are not applied on top of that.
>
>
>
> Regards,
>
> Samuel
>
>
>
> *From:* Pce <pce-bounces@ietf.org> *On Behalf Of * Dhruv Dhody
> *Sent:* Tuesday, September 19, 2023 5:48 AM
> *To:* peng.shaofu@zte.com.cn
> *Cc:* pce@ietf.org
> *Subject:* Re: [Pce] [PCE]: Draft-ietf-pce-sid-algo: Prefer Intra vs
> Inter-domain
>
>
>
> Hi Marcel, PSF,
>
>
>
> Speaking as a WG participant...
>
>
>
> Note that we do have a metric type "T=20: Domain Count metric (number of
> domains crossed)."; we can simply use this metric type, asking the PCE to
> optimize based on this which should lead to preferring intra-domain paths.
> See https://www.rfc-editor.org/rfc/rfc8685.html#section-3.5
>
>
>
> Thanks!
>
> Dhruv
>
>
>
> On Tue, Sep 19, 2023 at 9:04 AM <peng.shaofu@zte.com.cn> wrote:
>
>
>
> Hi Marcel,
>
>
>
> May it be a local policy of PCE ?
>
> For a given <ingress PE, egress PE> that belongs to the same domain, it
> may be
>
> the default policy for PCE to calculate a candidate path intra domain.
>
> Otherwise, it may bring unnecessary complexity. For example, for a real
> inter-domain
>
> path requirement of <ingress PE, egress PE> that belongs to the different
> domain,
>
> the intention is to split the path calculation requirements into multiple
> domains, e.g,
>
> <ingress PE, ABR1> for domain 1, <ABR1, ABR2> for domain 2, etc. Now, in
> this case,
>
> does <ingress PE, ABR1> itself again get a inter-domain path ? In theory,
> yes. But in
>
> reality, it doesn't make sense.
>
>
>
> Regards,
>
> PSF
>
>
>
> Original
>
> *From: *MarcelReuter(External) <marcel.reuter.external@telefonica.com>
>
> *To: *pce@ietf.org <pce@ietf.org>;
>
> *Date: *2023年09月15日 16:25
>
> *Subject: [Pce] [PCE]: Draft-ietf-pce-sid-algo: Prefer Intra vs
> Inter-domain*
>
> _______________________________________________
> Pce mailing list
> Pce@ietf.org
> https://www.ietf.org/mailman/listinfo/pce
>
> Aloha,
>
> Dear colleagues,
>
>
>
> I have a question regarding the PCE with SR Flex-algo and multiple IGP
> domains.
>
>
>
> In my understanding in each IGP Domain the Flex-Algo is calculated
> independently of each other domain.
>
> The PCE should have the view of all IGP domains, including IGP metrics and
> delay metrics.
>
>
>
> So if the PCE calculate a path and ingress and egress PE are in the same
> IGP domain,
>
> It would be preferable to choose an IGP intra domain vs using another IGP
> as transit.
>
> Or at least have the possibility to choose or prefer an Intra-Domain path
> (with a flag maybe?)
>
>
>
> Reason:
>
> Especially in mobile operator RAN networks, there could be bandwidth
> limitations in RAN IGP domains, but still a lower delay path.
>
>
>
> What’s your opinion about this?
>
>
>
> Thanks
>
> Marcel
>
>
>
>
>
>
>
>
>
>
>
>
>
>
> ------------------------------
>
>
> 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
> Pce@ietf.org
> https://www.ietf.org/mailman/listinfo/pce
>
> _______________________________________________
> Pce mailing list
> Pce@ietf.org
> https://www.ietf.org/mailman/listinfo/pce
>