Re: [mpls] FW: New Version Notification for draft-jags-mpls-ps-mna-hdr-00.txt
Loa Andersson <[email protected]> Thu, 20 Apr 2023 11:20:39 +0200
| Newsgroups | gmane.ietf.pwe3,gmane.ietf.mpls |
|---|---|
| Message-ID | <[email protected]> |
Authors, Working Group,
It is is a mystery to me why adding a new first nibble that is not
precise, rather than to trust the the P-bit in the LSE following the MNA
label:
0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Opcode | Data |P|IHS|S| Res |U| NASL |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
which give you a precise pointer to the PSD, is not considered "cleaner"
than trusting the first nibble.
/Loa
On 2023-03-28 22:58, Rakesh Gandhi wrote:
> Hi Loa,
>
> We, authors, feel that having a new first Nibble IANA assigned would be
> a cleaner solution, but we also like to hear from the other side of the
> house.
>
> Thanks,
> Rakesh
>
>
> On Fri, Mar 17, 2023 at 3:56 AM Loa Andersson <[email protected]
> <mailto:[email protected]>> wrote:
>
> Rakesh,
>
> Thanks for response, I'd like to point out
>
> - the first nibble is never on its own a sufficient indication for what
> the payload a a packet is, it might be an Ethernet PW without
> control
> word, where the first nibble accidentally is a value that we
> assigned
> for some payload.
> - something more is needed to with sufficient accuracy understand what
> the payload is, for PSD this is the P-bit in the OpCode LSE.
> - actually the the P-bit in the OpCode LSE is sufficient in itself, we
> don't need the first nibble, unless we for some reason want both
> brace and waist belt, but I can't see why
> - first nibbles is a scarce resource that should only be allocated if we
> really need it.
>
> Maybe someone from the the pseudo wire side of the house can confirm
> this.
>
> /Loa
>
>
> On 2023-03-15 13:16, Rakesh Gandhi wrote:
> > Hi Loa,
> >
> > Authors discussed the first nibble after BOS.
> > Re-using any existing Nibble (e.g. 0000b for CW or 0001b for
> G-ACH) can
> > lead to backwards compatibility issues on the legacy devices.
> > Note that legacy devices may not support MNA sub-stack.
> > It would be good to assign a new nibble (e.g., 0x2 = 0010b,
> currently
> > not assigned) to avoid such issues.
> > We can agree on this (i.e. assigning a new nibble for PSD), we can
> > update the draft accordingly.
> >
> > thanks,
> > Rakesh
> >
> >
> >
> >
> > On Fri, Mar 10, 2023 at 9:40 AM Loa Andersson
> <[email protected] <mailto:[email protected]>
> > <mailto:[email protected] <mailto:[email protected]>>> wrote:
> >
> > All,
> >
> > I have a question that is not new, and I’m still uncertain
> what the
> > correct answer is.
> >
> > I’m not certain that we should consider “the first nibble” as
> part
> > of the MNA PSD. Admittedly it is part of PSD, but not part of the
> > MNA PSD.
> >
> > We could say that MNA PSD start after the first nibble. If the
> > PSD-bit is set in the MNA-label LSE, we can safely ignore the
> first
> > nibble, if it is not set we need to look at the first nibble, and
> > the data following the first nibble is not MNA ancillary data.
> >
> > I see no meed to define a PSD first nibble. It would also avoid a
> > potential ambiguity in using the Generic Associated Channel
> nibble.
> >
> > For MNA the first should be set to 0000b when sent, and
> ignored when
> > received.
> >
> > /Loa
> >
> > Sent from my iPhone
> >
> >> On 10 Mar 2023, at 13:59, Jaganbabu Rajamanickam (jrajaman)
> >> <[email protected]
> <mailto:[email protected]>
> >> <mailto:[email protected]
> <mailto:[email protected]>>> wrote:
> >>
> >>
> >>
> >> Hello Everyone,____
> >>
> >> __ __
> >>
> >> We like to introduce our new draft on Post-Stack MNA
> solution.____
> >>
> >> Welcome your review comments and suggestions.____
> >>
> >> __ __
> >>
> >> Thanx,____
> >>
> >> Jags____
> >>
> >> __ __
> >>
> >> *From: *[email protected]
> <mailto:[email protected]> <mailto:[email protected]
> <mailto:[email protected]>>
> >> <[email protected] <mailto:[email protected]>
> <mailto:[email protected] <mailto:[email protected]>>>
> >> *Date: *Friday, March 10, 2023 at 7:52 AM
> >> *To: *Jaganbabu Rajamanickam (jrajaman) <[email protected]
> <mailto:[email protected]>
> >> <mailto:[email protected] <mailto:[email protected]>>>,
> Jie Dong <[email protected] <mailto:[email protected]>
> >> <mailto:[email protected] <mailto:[email protected]>>>,
> Rakesh Gandhi (rgandhi)
> >> <[email protected] <mailto:[email protected]>
> <mailto:[email protected] <mailto:[email protected]>>>, Royi Zigler
> >> <[email protected] <mailto:[email protected]>
> <mailto:[email protected]
> <mailto:[email protected]>>>, Tony
> >> Li <[email protected] <mailto:[email protected]>
> <mailto:[email protected] <mailto:[email protected]>>>
> >> *Subject: *New Version Notification for
> >> draft-jags-mpls-ps-mna-hdr-00.txt____
> >>
> >>
> >> A new version of I-D, draft-jags-mpls-ps-mna-hdr-00.txt
> >> has been successfully submitted by Jaganbabu Rajamanickam and
> >> posted to the
> >> IETF repository.
> >>
> >> Name: draft-jags-mpls-ps-mna-hdr
> >> Revision: 00
> >> Title: Post-Stack MPLS Network Action (MNA) Solution
> >> Document date: 2023-03-10
> >> Group: Individual Submission
> >> Pages: 17
> >> URL:
> >>
> https://www.ietf.org/archive/id/draft-jags-mpls-ps-mna-hdr-00.txt
> <https://www.ietf.org/archive/id/draft-jags-mpls-ps-mna-hdr-00.txt>
> >>
> <https://www.ietf.org/archive/id/draft-jags-mpls-ps-mna-hdr-00.txt
> <https://www.ietf.org/archive/id/draft-jags-mpls-ps-mna-hdr-00.txt>>
> >> Status:
> >> https://datatracker.ietf.org/doc/draft-jags-mpls-ps-mna-hdr/
> <https://datatracker.ietf.org/doc/draft-jags-mpls-ps-mna-hdr/>
> >>
> <https://datatracker.ietf.org/doc/draft-jags-mpls-ps-mna-hdr/
> <https://datatracker.ietf.org/doc/draft-jags-mpls-ps-mna-hdr/>>
> >> Html:
> >>
> https://www.ietf.org/archive/id/draft-jags-mpls-ps-mna-hdr-00.html
> <https://www.ietf.org/archive/id/draft-jags-mpls-ps-mna-hdr-00.html>
> >>
> <https://www.ietf.org/archive/id/draft-jags-mpls-ps-mna-hdr-00.html <https://www.ietf.org/archive/id/draft-jags-mpls-ps-mna-hdr-00.html>>
> >> Htmlized:
> >> https://datatracker.ietf.org/doc/html/draft-jags-mpls-ps-mna-hdr
> <https://datatracker.ietf.org/doc/html/draft-jags-mpls-ps-mna-hdr>
> >>
> <https://datatracker.ietf.org/doc/html/draft-jags-mpls-ps-mna-hdr
> <https://datatracker.ietf.org/doc/html/draft-jags-mpls-ps-mna-hdr>>
> >>
> >>
> >> Abstract:
> >> This document defines the Post-Stack MPLS Network Action
> (MNA)
> >> solution for carrying Network Actions and Ancillary Data
> after the
> >> MPLS label stack based on In-Stack MNA solution defined
> in draft-
> >> ietf-mpls-mna-hdr. MPLS Network Actions can be used to
> influence
> >> packet forwarding decisions, carry additional OAM information
> >> in the
> >> MPLS packet or perform user-defined operations. This
> document
> >> addresses the MNA requirements specified in
> draft-ietf-mpls-mna-
> >> requirements. This document follows the MNA framework
> specified in
> >> draft-ietf-mpls-mna-fwk.
> >>
> >>
> >>
> >>
> >> The IETF Secretariat
> >>
> >> ____
> >>
> >> _______________________________________________
> >> mpls mailing list
> >> [email protected] <mailto:[email protected]> <mailto:[email protected]
> <mailto:[email protected]>>
> >> https://www.ietf.org/mailman/listinfo/mpls
> <https://www.ietf.org/mailman/listinfo/mpls>
> >> <https://www.ietf.org/mailman/listinfo/mpls
> <https://www.ietf.org/mailman/listinfo/mpls>>
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> >
> >
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>
> --
> Loa Andersson email: [email protected] <mailto:[email protected]>
> Senior MPLS Expert [email protected] <mailto:[email protected]>
> Bronze Dragon Consulting phone: +46 739 81 21 64
>
--
Loa Andersson email: [email protected]
Senior MPLS Expert [email protected]
Bronze Dragon Consulting phone: +46 739 81 21 64
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