Re: [Detnet] Magnus Westerlund's Discuss on draft-ietf-detnet-mpls-over-udp-ip-07: (with DISCUSS)

[Magnus Westerlund <[e-mail]>]

Hi

Thanks for your work. Yes, what you propose do solve my discuss. Please publish
and I will clear.

Cheers

Magnus


On Thu, 2020-12-10 at 15:17 +0000, Balázs Varga A wrote:
> Hi Magnus,
> 
> We have discussed the update with the authors + DavidB with the result below.
> One more bullet added + clarification text to the paragraph after the list.
> 
> OLD TEXT
> 5.  Management and Control Information Summary
>    The following summarizes the set of information that is needed to
>    configure DetNet MPLS over UDP/IP:
>    o  Label information (A-labels, S-labels and F-labels) to be mapped
>       to UDP/IP flow.  Note that for example, a single S-Label can map
>       to multiple sets of UDP/IP information when PREOF is used.
>    o  IPv4 or IPv6 source address field.
>    o  IPv4 or IPv6 destination address field.
>    o  DSCP Field in either IPv4 Type of Service or IPv6 Traffic Class
>       Fields.
>    o  UDP Source Port.
>    o  UDP Destination Port.
>    This information MUST be provisioned per DetNet flow via
>    configuration, e.g., via the controller [RFC8655] or management
>    plane.
>  
> NEW TEXT
> 5.  Management and Control Information Summary
>    The following summarizes the minimum set of information that is needed to
>    configure DetNet MPLS over UDP/IP:
>    o  Label information (A-labels, S-labels and F-labels) to be mapped
>       to UDP/IP flow.  Note that for example, a single S-Label can map
>       to multiple sets of UDP/IP information when PREOF is used.
>    o  IPv4 or IPv6 source address field.
>    o  IPv4 or IPv6 destination address field.
>    o  DSCP Field in either IPv4 Type of Service or IPv6 Traffic Class
>       Fields.
>    o  UDP Source Port.
>    o  UDP Destination Port.
>    o  use/non-use of UDP checksum.
>    This information MUST be provisioned per DetNet flow via
>    configuration, e.g., via the controller [RFC8655] or management
>    plane. Not using the UDP checksum has to be evaluated on a
>    case-by-case basis for a given network scenario based on the
>    exception criteria’s defined in [RFC7510], particularly when 
>    IPv6 is used.
> END
> 
> I hope that has resolved your concerns, please confirm.
> 
> Many thanks
> Bala'zs
> 
> 
> -----Original Message-----
> From: Magnus Westerlund <[e-mail]> 
> Sent: Thursday, December 3, 2020 10:13 AM
> To: [e-mail]; balazs.a.varga=[e-mail]; 
> [e-mail]
> Cc: [e-mail]; [e-mail]; 
> [e-mail]; [e-mail]
> Subject: Re: [Detnet] Magnus Westerlund's Discuss on draft-ietf-detnet-mpls-
> over-udp-ip-07: (with DISCUSS)
> 
> Hi,
> 
> David's suggestions is definitely the direction I was considering to resolve
> this.
> 
> Cheers
> 
> Magnus
> 
> On Wed, 2020-12-02 at 22:40 +0000, Black, David wrote:
> > Hi Balazs,
> > 
> > Digging in a little deeper, I concur with Magnus's underlying concern that
> > this draft ought to say something about UDP checksums with IPv6.  There's a
> > useful starting point at the end of the Introduction (Section 1):
> > 
> >    As specified in [RFC7510]: "MPLS-in-UDP MUST NOT be used over the
> >    general Internet, or over non-cooperating network operators, to carry
> >    traffic that is not congestion controlled."  This does apply to
> >    DetNet networks as this document focuses on solutions for networks
> >    that are under a single administrative control or within a closed
> >    group of administrative control.
> > 
> > That suggests that the first two exceptions (a & b)  in Section 3.1 of RFC
> > 7510 (both of which involve single administrative control) are more likely
> > to
> > apply to DetNet than the third one (c, based on higher layer recovery and/or
> > error tolerance).  It could be helpful to say that in an added paragraph on
> > UDP checksums (for both v4 and v6) at the end of Section 4 in this draft.
> > 
> > I would also suggest aligning the text quoted above (from the end of Section
> > 1) with the text used in exceptions a. & b. in Section 3.1 of RFC 7510, as I
> > think roughly the same scope is intended.  In particular, it appears to me
> > that this draft's notion of "closed group of administrative control" would
> > fall under the notion of "single administrative control" in RFC 7510 (FWIW,
> > I'm an author of RFC 7510).
> > 
> > The suggestion to add use/non-use of UDP checksum to the list of management
> > and control information in Section 5 is a good idea - that addition ought to
> > cite Section 3.1 of RFC 7510 for the conditions under which the UDP checksum
> > may be disabled for IPv6 (per RFC 7510, UDP checksum for IPv6 "MUST be
> > implemented" for MPLS-in-UDP).
> > 
> > Thanks, --David
> > 
> > > -----Original Message-----
> > > From: detnet <[e-mail]> On Behalf Of Balázs Varga A
> > > Sent: Wednesday, December 2, 2020 12:25 PM
> > > To: Magnus Westerlund; The IESG
> > > Cc: [e-mail]; [e-mail]; draft-ietf-detnet-mpls-over-udp-
> > > [e-mail]; [e-mail]
> > > Subject: Re: [Detnet] Magnus Westerlund's Discuss on draft-ietf-detnet-
> > > mpls-
> > > over-
> > > udp-ip-07: (with DISCUSS)
> > > 
> > > 
> > > [EXTERNAL EMAIL]
> > > 
> > > Hi,
> > > 
> > > Chapter 5. of draft-ietf-detnet-mpls-over-udp-ip provides a _non-
> > > exhaustive_ 
> > > list of
> > > control and management plane information.
> > > DetNet does not changes rules of rfc7510: if the exceptions listed in 3.1
> > > of
> > > rfc7510
> > > applies, then using zero checksum is allowed; otherwise not.
> > > 
> > > A possible solution can be to add an additional information element to the
> > > list in
> > > chapter 5, which allow or not the usage of zero-checksum.
> > > 
> > > Thanks & Cheers
> > > Bala'zs
> > > 
> > > 
> > > -----Original Message-----
> > > From: detnet <[e-mail]> On Behalf Of Magnus Westerlund via
> > > Datatracker
> > > Sent: Wednesday, December 2, 2020 4:47 PM
> > > To: The IESG <[e-mail]>
> > > Cc: [e-mail]; [e-mail]; draft-ietf-detnet-mpls-over-udp-
> > > [e-mail]; [e-mail]
> > > Subject: [Detnet] Magnus Westerlund's Discuss on draft-ietf-detnet-mpls-
> > > over-udp-
> > > ip-07: (with DISCUSS)
> > > 
> > > Magnus Westerlund has entered the following ballot position for
> > > draft-ietf-detnet-mpls-over-udp-ip-07: Discuss
> > > 
> > > When responding, please keep the subject line intact and reply to all
> > > email
> > > addresses included in the To and CC lines. (Feel free to cut this
> > > introductory
> > > paragraph, however.)
> > > 
> > > 
> > > Please refer to https://www.ietf.org/iesg/statement/discuss-criteria.html
> > > for more information about IESG DISCUSS and COMMENT positions.
> > > 
> > > 
> > > The document, along with other ballot positions, can be found here:
> > > https://datatracker.ietf.org/doc/draft-ietf-detnet-mpls-over-udp-ip/
> > > 
> > > 
> > > 
> > > ----------------------------------------------------------------------
> > > DISCUSS:
> > > ----------------------------------------------------------------------
> > > 
> > > So there might be something missing here in regards to zero-checksum in
> > > UDP
> > > when using IPv6. So Section 3.1 in RFC 7510 discusses this for MPLS over
> > > UDP
> > > and
> > > have some considerations that needs to be done if one are intending to use
> > > zero
> > > checksum. To me it appears that DETNET flows can not be guaranteed to
> > > always
> > > fulfill these, and in case you think you can motivate it should probably
> > > be
> > > stated
> > > explicitly and normatively allow it. So if it can't be guaranteed to
> > > fulfill
> > > these
> > > requirements then the next question exists: Do the possibility to use
> > > zero-
> > > checksum
> > > for this flow become something the control plane needs to signal it?
> > > 
> > > 
> > > 
> > > 
> > > 
> > > _______________________________________________
> > > detnet mailing list
> > > [e-mail]
> > > https://www.ietf.org/mailman/listinfo/detnet
> > > 
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