Re: [mpls] Comments on draft draft-cheng-mpls-inband-pm-encapsulation

[Greg Mirsky <[e-mail]>]

Hi Loa,
I think that the IPPM document already exists - it is RFC 8321. Also, there
are a number of drafts, e.g., in BIER, SFC, and NVO3 WGs, that describe how
the Alternate Marking method can be applied to the particular network.

Regards,
Greg

Regards,
Greg

On Tue, Nov 19, 2019 at 9:03 AM Loa Andersson <[e-mail]> wrote:

> Rakesh,
>
> Good idea, would be enough if we captured this in the MPLS document, or
> should it be in the IPPM draft also?
>
> /Loa
>
> PS
> I added the IPPM chairs to this thread.
>
> On 19/11/2019 07:52, Rakesh Gandhi wrote:
> > Hi Folks,
> > Many thanks for providing the detailed comparison information for the
> > two approaches. It would be good to capture them in the draft.
> >
> > Thanks,
> > Rakesh
> >
> >
> > On Mon, Nov 18, 2019 at 5:55 PM Haoyu Song <[e-mail]
> > <mailto:[e-mail]>> wrote:
> >
> >     I agree the two techniques covers different use cases with different
> >     cost. Each has its own merits. Sometimes header overhead and data
> >     export bandwidth  are big concerns.  If AM is all user needs,
> >     there's  no point to use a more powerful yet more costly technique.
> >
> >     Haoyu
> >
> >
> >
> >
>  ------------------------------------------------------------------------
> >     *发件人:* mpls <[e-mail] <mailto:mpls-
> >     [e-mail]>> 代表 Giuseppe Fioccola
> >     <[e-mail] <mailto:[e-mail]>>
> >     *发送时间:* 2019年11月18日星期一 下午5:17
> >     *收件人:* Greg Mirsky; Rakesh Gandhi
> >     *抄送:* [e-mail] <mailto:[e-mail]>;
> >     [e-mail]
> >     <mailto:[e-mail]>
> >     *主题:* Re: [mpls] Comments on draft
> >     draft-cheng-mpls-inband-pm-encapsulation
> >
> >     Hi All,
> >
> >     I agree with Greg. And there are at least 3 big differences between
> >     IOAM/IOAM-DEX and Alternate Marking:
> >
> >     1) IOAM/IOAM-DEX is a packet level monitoring while Alternate
> >     Marking is a flow monitoring solution
> >
> >     2) IOAM/IOAM-DEX introduces a new encapsulation while Alternate
> >     Marking can be encapsulated more easily and with less overhead (e.g.
> >     dedicated bits or TLV)
> >
> >     3) IOAM/IOAM-DEX architecture is more static (i.e. data specified by
> >     the IOAM-Trace-Type are exported by the nodes) while Alternate
> >     Marking includes a dynamic approach and can be adapted to the
> >     network conditions (i.e. draft-ietf-ippm-multipoint-alt-mark)
> >
> >     Best Regards,
> >
> >     Giuseppe
> >
> >     *From:*mpls [mailto:[e-mail]
> >     <mailto:[e-mail]>] *On Behalf Of *Greg Mirsky
> >     *Sent:* Monday, November 18, 2019 8:07 AM
> >     *To:* Rakesh Gandhi <[e-mail]
> >     <mailto:[e-mail]>>
> >     *Cc:* [e-mail] <mailto:[e-mail]>;
> >     [e-mail]
> >     <mailto:[e-mail]>
> >     *Subject:* Re: [mpls] Comments on draft
> >     draft-cheng-mpls-inband-pm-encapsulation
> >
> >     Hi Rakesh, et al.,
> >
> >     I don't consider AltMark/SFL as just a lighter version of DEX. One
> >     of the benefits of Alt.Marking, in my opinion, is that a node may be
> >     aggregating measurements, and export not the raw data, as with DEX,
> >     but calculated performance metrics.
> >
> >     Regards,
> >
> >     Greg
> >
> >     On Mon, Nov 18, 2019 at 2:57 PM Rakesh Gandhi
> >     <[e-mail] <mailto:[e-mail]>> wrote:
> >
> >         Hi Tianran,
> >
> >         Thanks for your reply. But this does not answer my question:)
> >
> >         Question is why a light way is required when there is already
> >         direct export IOAM available.
> >
> >         Regarding the SFL comment, when SFLs are used, we do not need
> >         L/D flags in the header for coloring, as an SFL itself indicates
> >         the color.
> >
> >         Thanks,
> >
> >         Rakesh
> >
> >         On Mon, Nov 18, 2019 at 1:57 PM Tianran Zhou
> >         <zhoutianran@huawei..com <mailto:[e-mail]>> wrote:
> >
> >             Hi Rakesh,
> >
> >             Thanks for your interest.
> >
> >             I think the requirement of using alternate marking for mpls
> >             pm has already been acknowledged by this wg. As Tarek
> >             mentioned several times, the SFL is produced for this usage.
> >
> >             We bring a new encapsulation here to mitigate the deployment
> >             issue when we try to apply the SFL.
> >
> >             That’s our simple motivation.
> >
> >             BR,
> >
> >             Tianran
> >
> >             *发件人**:*Rakesh Gandhi [mailto:[e-mail]
> >             <mailto:[e-mail]>]
> >             *发送时间:* 2019年11月18日 6:20
> >             *收件人:* Tianran Zhou <[e-mail]
> >             <mailto:[e-mail]>>
> >             *抄送:* Weiqiang Cheng <[e-mail]
> >             <mailto:[e-mail]>>; Tarek Saad
> >             <[e-mail] <mailto:[e-mail]>>;
> >             [e-mail]
> >             <mailto:[e-mail]>;
> >             [e-mail] <mailto:[e-mail]>
> >             *主题:* Re: [mpls] Comments on draft
> >             draft-cheng-mpls-inband-pm-encapsulation
> >
> >             Hi Tianran,
> >
> >             Thanks for your reply.
> >
> >             Right, IOAM Direct Export covers more than just PM. Both
> >             drafts would also require special labels for the direct
> >             export for MPLS case. With this in mind, you may clarify in
> >             the draft why lite way is required for PM for MPLS case and
> >             how it is achieved with your draft compared to the IOAM
> >             direct export.
> >
> >             Thanks,
> >
> >             Rakesh
> >
> >             On Sun, Nov 17, 2019 at 12:44 PM Tianran Zhou
> >             <[e-mail] <mailto:[e-mail]>>
> wrote:
> >
> >                 Hi Rakesh,
> >
> >                 As the coauthor of both drafts, I think they are
> different.
> >
> >                 This draft is only for performance measurement in a lite
> >                 way.
> >
> >                 IOAM-DEX is to collect data based on the trace type
> >                 instruction.
> >
> >                 Thanks,
> >
> >                 Tianran
> >
> >                 *发件人**:*Rakesh Gandhi [mailto:[e-mail]
> >                 <mailto:[e-mail]>]
> >                 *发送时间**:*2019年11月13日5:12
> >                 *收件人**:*Weiqiang Cheng <[e-mail]
> >                 <mailto:[e-mail]>>
> >                 *抄送**:*Tarek Saad <[e-mail]
> >                 <mailto:[e-mail]>>;
> >                 [e-mail]
> >                 <mailto:
> [e-mail]>;
> >                 [e-mail] <mailto:[e-mail]>
> >                 *主**题**:*Re: [mpls] Comments on draft
> >                 draft-cheng-mpls-inband-pm-encapsulation
> >
> >                 Hi Authors,
> >
> >                 FYI:
> >
> >                 The draft has some similarity with the functionality
> >                 defined in the following draft which is generically
> >                 applicable to the all encap types:
> >
> >
> https://tools.ietf.org/html/draft-ioamteam-ippm-ioam-direct-export-00
> >                 <
> https://nam03.safelinks.protection.outlook.com/?url=https%3A%2F%2Ftools.ietf.org%2Fhtml%2Fdraft-ioamteam-ippm-ioam-direct-export-00&data=02%7C01%7Chaoyu.song%40futurewei.com%7Cb28cbc36bf1c4dc2b1ad08d76c082e64%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C637096654713533899&sdata=8%2FMYlbsByQtiewLK0%2BgHzGu9rAJybEVbozdAG6mH5Jo%3D&reserved=0
> >
> >
> >                 You may want to have a look.
> >
> >                 Thanks,
> >
> >                 Rakesh
> >
> >                 On Wed, Sep 25, 2019 at 3:00 AM Weiqiang Cheng
> >                 <[e-mail]
> >                 <mailto:[e-mail]>> wrote:
> >
> >                     Hi Tarek,
> >
> >                     Thank you very much for your comments.
> >
> >                     We authors had some discussion on it and our
> >                     feedback is in-line.
> >
> >                     B.R.
> >
> >                     Weiqiang Cheng
> >
> >                     *发件人**:*mpls [mailto:[e-mail]
> >                     <mailto:[e-mail]>] *代表***Tarek Saad
> >                     *发送时间**:*2019年7月22日21:34
> >                     *收件人**:*draft-cheng-mpls-inband-pm-
> >                     [e-mail]
> >                     <mailto:
> [e-mail]>
> >                     *抄送**:*[e-mail] <mailto:[e-mail]>
> >                     *主**题**:*[mpls] Comments on draft
> >                     draft-cheng-mpls-inband-pm-encapsulation
> >
> >                     Hi authors,
> >
> >                      From reading your draft, have the following
> comments:
> >
> >                       * There’s a similar proposal in
> >                         draft-ietf-mpls-rfc6374-sfl that the WG has
> >                         worked on to achieve similar PM measurements.
> >                         That proposal did not require a special label,
> >                         nor requires carrying 2 new additional labels in
> >                         label stack. Do you see any downside to the
> >                         approach in draft-ietf-mpls-rfc6374-sfl vs. the
> >                         new one introduced one? If so, can this be
> >                         highlighted....
> >
> >                     [Weiqiang]   Yes, the SFL proposal was carefully
> >                     considered before this draft was written, and the
> >                     major downsides of SFL include:
> >
> >                     1. It seems that the current version of SFL targets
> >                     at end-to-end performance measurement,  but our
> >                     draft targets at both end-to-end and hop-by-hop
> >                     performance measurement. Of course, someone may
> >                     argue that the SFL can be extended to support
> >                     hop-by-hop performance measurement, but if that
> >                     happens, the SFL method is too complex for label
> >                     management, because basically it assigns two
> >                     implications to one mpls label.
> >
> >                     2. The SFL method can't be applied when we want to
> >                     achieve performance measurements on both LSP and
> >                     PW synchronously, but the method described in our
> >                     draft can simply achieve that.
> >
> >                       * It appears that the label below the “Flow
> >                         Indicator Label” is used to carry/embed context
> >                         information: including a flow identifier and
> >                         additional flags - that are set by ingress.
> >                         Normally, MPLS labels do not embed any context
> >                         information about the flow they carry within
> >                         them. The context of the label is held by the
> >                         node that allocates the label.
> >
> >                     [Weiqiang]   Your understanding is perfectly
> >                     correct. And please also note that in our draft the
> >                     Flow-ID label values are allocated by an external
> >                     NMS or a controller, that means the context of the
> >                     Flow-ID label is held by all the nodes within the
> >                     administrative domain. Furthermore, I want to stress
> >                     that the method described in our draft has already
> >                     been implemented by more than two vendors, and we
> >                     plan to deploy it in our commercial 5G backhaul
> >                     networks.
> >
> >                     Regards,
> >
> >                     Tarek
> >
> >                     _______________________________________________
> >                     mpls mailing list
> >                     [e-mail] <mailto:[e-mail]>
> >                     https://www.ietf.org/mailman/listinfo/mpls
> >                     <
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> >
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>
> --
>
>
> Loa Andersson                        email: [e-mail]
> Senior MPLS Expert
> Bronze Dragon Consulting             phone: [phone]
>
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