Re: [Teas] Robert Wilton's Discuss on draft-ietf-teas-gmpls-signaling-smp-11: (with DISCUSS)

["Rob Wilton (rwilton)" <[e-mail]>]

Hi Jeong-dong & John

Thanks.  I've now cleared my discuss.

Regards,
Rob


> -----Original Message-----
> From: [e-mail] <[e-mail]>
> Sent: 19 April 2022 11:34
> To: The IESG <[e-mail]>; Rob Wilton (rwilton) <[e-mail]>
> Cc: [e-mail]; [e-mail];
> [e-mail]; [e-mail]
> Subject: RE: Robert Wilton's Discuss on draft-ietf-teas-gmpls-signaling-smp-
> 11: (with DISCUSS)
> 
> Hi, Robert.
> 
> 
> Thank you for your review and comments.
> 
> Indeed, it is possible that the current text may lead to confusion and
> ambiguity.
> 
> The co-authors of this draft would like to revise the draft as per your first
> suggestion. We want to keep the "If 0x20 (SMP), the N bit MUST be set to 1."
> sentence, since it can be helpful to have an explicit statement in the part that
> defines the values of the message bits.
> 
> We will upload a revised text shortly.
> 
> 
> Best regards,
> 
> Jeong-dong (on behalf of the co-authors)
> 
> 
> 
> -----Original Message-----
> From:  "Robert Wilton via Datatracker" <[e-mail]>
> To:     "The IESG" <[e-mail]>;
> Cc:      <[e-mail]>;   <teas-
> [e-mail]>;   <[e-mail]>;   <[e-mail]>;
> <[e-mail]>;
> Sent:  2022-04-07 (목) 20:43:42 (UTC+09:00)
> Subject: Robert Wilton's Discuss on draft-ietf-teas-gmpls-signaling-smp-11:
> (with DISCUSS)
> 
> Robert Wilton has entered the following ballot position for
> draft-ietf-teas-gmpls-signaling-smp-11: Discuss
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> 
> ----------------------------------------------------------------------
> DISCUSS:
> ----------------------------------------------------------------------
> 
> Thanks for this document, and sorry for the late discuss, which should
> hopefully be trivial to fix.
> 
>    Notification (N): 1 bit
> 
>       When set to 1, this bit indicates that the control plane message
>       exchange is only used for notification during protection
>       switching.  When set to 0 (default), it indicates that the control
>       plane message exchanges are used for protection-switching
>       purposes.  The N bit is only applicable when the LSP Protection
>       Type Flag is set to 0x04 (1:N Protection with Extra- Traffic),
>       0x08 (1+1 Unidirectional Protection), 0x10 (1+1 Bidirectional
>       Protection), or 0x20 (Shared Mesh Protection).  If 0x20 (SMP), the
>       N bit MUST be set to 1.  The N bit MUST be set to 0 in any other
>       case.
> 
> I think that the way that this RFC4872 text has been updated makes this text
> unclear/ambiguous.
> 
> Specifically, I think that somebody could reasonably interpret this as saying
> that the N bit is set to 1 for SMP, and otherwise it must always be set to 0,
> but I don't think that is the intention.  So please can this be clarified.
> 
> One fix could be to swap the order of the last 2 sentences.  E.g.,
> 
>       or 0x20 (Shared Mesh Protection).  The N bit MUST
>       be set to 0 in any other case. If 0x20 (SMP), the
>       N bit MUST be set to 1.
> 
> Alternatively, I think that you could possibly just remove the "If 0x20 (SMP),
> the N bit MUST be set to 1." and instead rely on the text in 5.2/5.3, (perhaps
> strengthening with RFC 2119 language if required).
> 
> Regards,
> Rob
> 
> 
> 
> 
>