Re: [sfc] IETF WG state changed for draft-ietf-sfc-proof-of-transit

["Frank Brockners (fbrockne)" <[e-mail]>]

Hi Med,

Thanks a lot for your comments. Please see inline (...FB)

> -----Original Message-----
> From: [e-mail] <[e-mail]>
> Sent: Freitag, 19. Juni 2020 08:36
> To: [e-mail]
> Cc: Joel M. Halpern <[e-mail]>; [e-mail]
> Subject: RE: [sfc] IETF WG state changed for draft-ietf-sfc-proof-of-transit
> 
> Hi Franck, all,
> 
> I know that you are working on this since a while. Please find below some
> comments on the YANG part to hopefully save you some cycles during upcoming
> reviews:
> 
> (1) Remove "?" from the explanation text in Section 5.2.1

...FB: Will do.
> 
> (2)
> 
> OLD:
> The meaning of the symbols in these diagrams is
>    as follows:
> 
>    o  Brackets "[" and "]" enclose list keys.
> 
>    o  Abbreviations before data node names: "rw" means configuration
>       (read-write), and "ro" means state data (read-only).
> 
>    o  Symbols after data node names: "?" means an optional node, "!"
>       means a presence container, and "*" denotes a list and leaf-list.
> 
>    o  Parentheses enclose choice and case nodes, and case nodes are also
>       marked with a colon (":").
> 
>    o  Ellipsis ("...") stands for contents of subtrees that are not
>       shown.
> 
> NEW:
>   The meaning of the symbols in YANG tree diagrams is defined in [RFC8340].

...FB: Good point. We can indeed get rid of the legacy text and refer to RFC8340.
> 
> (3) Remove <CODE BEGINS> and <CODE ENDS> from the tree diagram

...FB: Will do.
> 
> (4) Instead of:
> 
>            +--rw active-profile-index?   profile-index-range
> 
> You can define a status leaf under pot-profile-list to indicate the activation
> status.

...FB: Very doable - especially since the open source implementation in VPP also only uses and active and a standby profile.
> 
> (5) Any reason why are you using version 1? If not, please update to "1.1"

...FB: Nothing specific. The model got defined (and implemented as part of OpenDaylight) back in 2016.

> 
> (6) As your groupings are called only once, and unless you want to define them
> as reusable by other modules, you may just define those as part of the main
> container.

...FB: We could consider doing so. The reason why we kept the model fairly stable so far was that there is an existing implementation in open source (Opendaylight), hence the preference to not change things unless there is a real need. Would you be ok to stay with the current structure?

> 
> (7) IANA Section should be updated as follows:
> 
> OLD:
>    This document does not require any actions from IANA.
> 
> NEW:
> 
>    IANA is requested to register the following URI in the "ns" subregistry within
>    the "IETF XML Registry" [RFC3688]:
> 
>       URI:  urn:ietf:params:xml:ns:yang:ietf-pot-profile
>       Registrant Contact:  The IESG.
>       XML:  N/A; the requested URI is an XML namespace.
> 
>    IANA is requested to register the following YANG module in the "YANG Module
>    Names" subregistry [RFC7950] within the "YANG Parameters" registry.
> 
>       Name:  ietf-pot-profile
>       Maintained by IANA:  N
>       Namespace:  urn:ietf:params:xml:ns:yang:ietf-pot-profile
>       Prefix:  ietf-pot-profile
>       Reference:  RFC XXXX
> 
> (7) You should update the Security Section as per
> https://trac.ietf.org/trac/ops/wiki/yang-security-guideline.

...FB: ACK on both points above.
> 
> And a more general note:
> 
> ==
>    Several deployments use Traffic Engineering, policy routing, Segment
>    Routing (SR), and Service Function Chaining (SFC) [RFC7665] to steer
>    packets through a specific set of nodes.  In certain cases,
>    regulatory obligations or a compliance policy require operators to
>    ^^^^^^^^^^^^^^^^^^^^^^
>    prove that all packets that are supposed to follow a specific path
>    are indeed being forwarded across and exact set of pre-determined
>    nodes.
> ==
> 
> Do you have pointers to such regulatory obligations? It would be good to add a
> pointer if you are aware of any. Thanks.

...FB: One of the co-authors and initiators of POT, Stephen, might have more specific references available. 
>From what I know, there are company policies that require path verification. In case we don't find a formal reference, we'll change the statement in the next revision and avoid mentioning "regulatory obligations".


> 
> Hope this helps.

Very helpful indeed. Thanks again.

Cheers, Frank
> 
> Cheers,
> Med
> 
> > -----Message d'origine-----
> > De : sfc [mailto:[e-mail]] De la part de Joel M. Halpern
> > Envoyé : mardi 16 juin 2020 15:42 À : [e-mail] Objet : Re: [sfc]
> > IETF WG state changed for draft-ietf-sfc-proof-of-transit
> >
> > The chairs are starting the WG last call for
> > draft-ietf-sfc-proof-of-transit.  Please reply explicitly whether you
> > think this is ready to go to the IETF for publication as a
> > Experimental RFC.
> > As noted below, the call runs through June 30.
> >
> > Note that silence does not imply consent, so please speak up.
> >
> > Yours,
> > Joel (& Jim)
> >
> > On 6/16/2020 9:32 AM, IETF Secretariat wrote:
> > >
> > > The IETF WG state of draft-ietf-sfc-proof-of-transit has been
> > > changed to
> > "In
> > > WG Last Call" from "WG Document" by Joel Halpern:
> > >
> > > https://datatracker.ietf.org/doc/draft-ietf-sfc-proof-of-transit/
> > >
> > > Comment:
> > > This starts WG last call for this document, ending June 30.
> > >
> >
> > _______________________________________________
> > sfc mailing list
> > [e-mail]
> > https://www.ietf.org/mailman/listinfo/sfc
> 
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