Re: [pim] Call for adoption: draft-voyer-pim-sr-p2mp-policy-00

[Gyan Mishra <[e-mail]>]

Hi Rishabh

Response in-line

Kind regards

Gyan

On Tue, Jan 21, 2020 at 1:31 PM Rishabh Parekh <[e-mail]> wrote:

> Gyan,
>
> >This draft documents the data plane aspects of instantiation of P2MP
> trees for ASM and SSM or MP2MP for PIM Birdir over SR-MPLS via centralized
> PCE controller. Does this model support distributed and hybrid models of
> tree instantiation.  That is not >mentioned in the draft.  Please point out
> where mentioned if it is so.  If this draft does not support hybrid or
> distributed instantiation please explain why.
>
> This draft do not cover distributed tree building protocols since
> these are already specified for both IP and MPLS.
>

    Gyan>I believe the main goal of this draft is introducing the P2MP MDT
instantiation root Tree-SID and leaf replication-SID over SR-MPLS.  Is this
the first draft that introduces these two new SIDs for multicast?

Gyan> Distributed tree building protocols over SR-MPLS would also use the
same MVPN procedures in RFC 6513 and 6514 ; however for P2MP trees to be
instantiation they would need the root tree-sid and leaf replication-sid
and use of binding sid for SR policy to steer traffic into the P2MP p-tree
as described in this draft.    What is sister draft if it exists that talks
about this very topic of  SR-MPLS P2MP p-tree instantiation using tree-sid
and replication-sid in a  distributed or hybrid model?


> >The document mentions SR but does not state SR-MPLS.  There are two
> flavors of SR via SR-MPLS reusing MPLS dataplane or SRv6 using IPv6
> dataplane.
> >I am guessing SRv6 MDT instantiation is out of scope of this document
> which should be mentioned
>
> Trees using SRv6 data plane can also be instantiated using SR-PCE,
> similar to SR-MPLS. This would be added in future revision of the doc.
>
> >Does this draft use reuse the MVPN procedures defined in RFC 6513 and
> 6514 instantiation of UI-PMSI MI-PMSI inclusive Default MDT and S-PMSI
> selective Data MDT.  In the draft I don’t see mention of reuse of the BGP
> MVPN procedures.
>
> This draft is just for tree instantiation.
> draft-parekh-bess-mvpn-sr-p2mp-01 documents use of such trees for
> MVPN.
>

 Gyan>  From the MVPN draft appears all the MVPN procedures are the same
for P2MP tree instantiation over SR using the new tree-sid and
replication-sid.  As far as the p-tree tunnel id  types that would be
supported I am guessing only IR (ingress replication)
and all the PIM trees for Rosen tunnels.  Anything RSVP TE or mLDP based
would not be supported.  I am guessing PIM Birdir c-multicast over p-tree
would not be supported since MP2MP would now not be possible over SR due to
lack of mLDP MP2MP LSP.  Im

Gyan>As far as MVPN since mostly there is no change for instantiation of
trees are the route types numbering 1-7 am guessing stays the same.  Not
sure if that is vendor specific with the MVPN route type numbering.

Gyan>Would BIER (bit indexes replication) for stateless trees be supported
with this draft or future updates?  I believe BIER supports MP2MP MDT trees
so If SR supports BIER then that could provide support for MP2MP.

>
>
> >This document does not talk about fast reroute of MDT in the context of
> SR-MPLS SR-TE
>
> There is a brief mention of FRR in Section 4.4.1
>
> Gyan>With FRR I see 1:1  backup  but would facility backup be supported
> N:1 .  Since SR-MPLS reused the ldp data plane with label stack traffic
> steering I think N:1 facility backup is still relevant. There maybe a
> future separate draft  on SR-TE P2P LSP unicast protection and P2MP MDT
> tree protection.


> Thanks,
>
> -Rishabh
>
>
>
>
> On Mon, Jan 20, 2020 at 3:18 PM Gyan Mishra <[e-mail]> wrote:
> >
> >
> > Authors
> >
> > I support but do have a few comments and questions on the draft below.
> >
> > This draft documents the data plane aspects of instantiation of P2MP
> trees for ASM and SSM or MP2MP for PIM Birdir over SR-MPLS via centralized
> PCE controller. Does this model support distributed and hybrid models of
> tree instantiation.  That is not mentioned in the draft.  Please point out
> where mentioned if it is so.  If this draft does not support hybrid or
> distributed instantiation please explain why.
> >
> > The document mentions SR but does not state SR-MPLS.  There are two
> flavors of SR via SR-MPLS reusing MPLS dataplane or SRv6 using IPv6
> dataplane.
> >
> > I am guessing SRv6 MDT instantiation is out of scope of this document
> which should be mentioned.
> >
> > Does this draft use reuse the MVPN procedures defined in RFC 6513 and
> 6514 instantiation of UI-PMSI MI-PMSI inclusive Default MDT and S-PMSI
> selective Data MDT.  In the draft I don’t see mention of reuse of the BGP
> MVPN procedures.
> >
> > This document does not talk about fast reroute of MDT in the context of
> SR-MPLS SR-TE.
> >
> >
> > Kind regards
> >
> > Gyan
> >
> > On Mon, Jan 20, 2020 at 6:03 PM Mehta, Dhaval (Nokia - US/Mountain View)
> <[e-mail]> wrote:
> >>
> >> I support.
> >>
> >>
> >>
> >> Thank you,
> >>
> >> Dhaval
> >>
> >>
> >>
> >> From: pim <[e-mail]> On Behalf Of Michael McBride
> >> Sent: Monday, January 13, 2020 4:25 PM
> >> To: [e-mail]
> >> Subject: [pim] Call for adoption: draft-voyer-pim-sr-p2mp-policy-00
> >>
> >>
> >>
> >> Happy New Year PIMers,
> >>
> >>
> >>
> >> Today begins a two week call for adoption of
> draft-voyer-pim-sr-p2mp-policy-00 involving p2mp tree construction in a
> segment routing domain.
> >>
> >>
> >>
> >> This draft has been presented in our face to face meetings, including
> most recently in Singapore, and the authors have asked for a call for
> adoption.
> >>
> >>
> >>
> >> https://tools.ietf.org/html/draft-voyer-pim-sr-p2mp-policy-00
> >>
> >>
> >>
> >> Please read the draft and let the wg know if you think it’s ready, or
> not, for adoption.
> >>
> >>
> >>
> >> thanks,
> >>
> >> mike
> >>
> >> _______________________________________________
> >> pim mailing list
> >> [e-mail]
> >> https://www.ietf.org/mailman/listinfo/pim
> >
> > --
> >
> > Gyan  Mishra
> >
> > Network Engineering & Technology
> >
> > Verizon
> >
> > Silver Spring, MD 20904
> >
> > Phone: [phone]
> >
> > Email: [e-mail]
> >
> >
> >
> > _______________________________________________
> > pim mailing list
> > [e-mail]
> > https://www.ietf.org/mailman/listinfo/pim
>
-- 

Gyan  Mishra

Network Engineering & Technology

Verizon

Silver Spring, MD 20904

Phone: [phone]

Email: [e-mail]