Re: [Detnet] Regarding the model for Active OAM packet

[Greg Mirsky <[e-mail]>]

Hi Loa,
that may work but the problem how ACH-based OAM packet been treated by
PREF, in my view, will still be there. d-CW and ACH/d-ACH both immediately
follow BoS label. d-CW includes the 28 bits-long Sequence Number field that
is used by the Elimination sub-function. PW ACH doesn't have any field that
may be monotonically increased. d-ACH may define the eight bits-long
Reserved field of PW ACH as Sequence Number, and then the Elimination
sub-function may treat 28 most significant bits as the sequence number.
That is what Mach and I will explore. There could be some problems but it
might work.

Regards,
Greg

On Fri, Sep 21, 2018 at 10:06 PM Loa Andersson <[e-mail]> wrote:

> Greg,
>
> can't this be done in a uniform way? E.g. :
>
> 0                                  31
> +--------+--------+--------+--------+
> |         MPLS Label Stack          |
> +--------+--------+--------+--------+
> |          GAL (s-bit = 1)          |
> +--------+--------+--------+--------+
> |    ACH – Type = DetNet OAM |
> +--------+--------+--------+--------+
> |     Header of DetNet OAM          | tot len and number of elements
> +--------+--------+--------+--------+
> |                                   | e.g. proactive Fault Man. OAM
> ~   DetNet OAM Element (DOE) 1      ~
> |                                   |
> +--------+--------+--------+--------+
> ~                                   ~ etc.
> +--------+--------+--------+--------+
> |                                   |
> ~  DetNet OAM Element (DOE) n-1     ~ e.g Perf. Mon. OAM tool(s)
> |                                   |
> +--------+--------+--------+--------+
> |                                   |
> ~   DetNet OAM Element (DOE) n      ~ etc.
> |                                   |
> +--------+--------+--------+--------+
> |                                   |
> ~   Upper Layer Protocols/Payload   ~
> |                                   |
> +--------+--------+--------+--------+
>
> The you just give each lemenet a structure, reuse whatever you want.
>
> /Loa
>
> On 2018-09-21 23:30, Greg Mirsky wrote:
> > Hi Loa,
> > DetNet OAM, in my view, is not another OAM function but includes FM and
> > PM OAM functions we have in any networking layer, e.g., IP or MPLS. I
> > believe we must have on-demand and proactive Fault Management OAM, as
> > well as Performance Monitoring OAM tool(s). Also, because of PREF,
> > on-demand OAM must be extended. Hence, my thought that BFD, RFC 6374,
> > etc. ACH types may be re-used on DetNet layer.
> >
> > Regards,
> > Greg
> >
> > On Fri, Sep 21, 2018 at 3:44 AM Loa Andersson <[e-mail]
> > <mailto:[e-mail]>> wrote:
> >
> >     Greg,
> >
> >     On 2018-09-20 20:55, Greg Mirsky wrote:
> >      > Hi Loa,
> >      > I agree that we can define new ACH Type that will have Sequence
> >     Number
> >      > immediately following the ACH.
> >
> >     OK!
> >
> >          > But then we'll need to re-define number
> >      > of Types, e.g., BFD, RFC 6374, etc. Or I misunderstood
> >     your suggestion.this probably
> >      >
> >     This probably the key, why do you need to redefine?
> >
> >     /Loa
> >      > Regards,
> >      > Greg
> >      >
> >      > On Thu, Sep 20, 2018 at 3:13 AM Loa Andersson <[e-mail]
> >     <mailto:[e-mail]>
> >      > <mailto:[e-mail] <mailto:[e-mail]>>> wrote:
> >      >
> >      >     Mach,
> >      >
> >      >     I'd like Stewart or Matthew to look at this, but as I
> >     understand it it
> >      >     is possible to define a new ACH-type that can do exactly what
> >     you want.
> >      >
> >      >     /Loa
> >      >
> >      >     On 2018-09-20 17:58, Mach Chen wrote:
> >      >      > Loa,
> >      >      >
> >      >      > GAL is just an OAM indicator, the problem here is that
> when do
> >      >     DetNet OAM, the d-CW will replaced by ACH or by GAL+ACH. No
> >     matter
> >      >     which way is used, to support the replication or elimination,
> >     there
> >      >     has to be a sequence number filed. But ACH (as its current
> >     defined)
> >      >     does not have such a field.
> >      >      >
> >      >      > My suggestion is to use the reserved field of ACH to carry
> >      >     sequence number of OAM packet,  and for those replication or
> >      >     elimination nodes, they do not have to differentiate whether a
> >      >     packet is OAM packet or a normal packet, they could just
> >     treat the
> >      >     right 28 bits of the ACH as the sequence number ( or treat
> >     the ACH
> >      >     as the d-CW), then both OAM and replication/elimination can be
> >      >     supported.
> >      >      >
> >      >      > Best regards,
> >      >      > Mach
> >      >      >
> >      >      >> -----Original Message-----
> >      >      >> From: detnet [mailto:[e-mail]
> >     <mailto:[e-mail]>
> >      >     <mailto:[e-mail]
> >     <mailto:[e-mail]>>] On Behalf Of Loa Andersson
> >      >      >> Sent: Thursday, September 20, 2018 3:21 PM
> >      >      >> To: Mach Chen <[e-mail]
> >     <mailto:[e-mail]>
> >      >     <mailto:[e-mail] <mailto:[e-mail]>>>;
> >     Greg Mirsky
> >      >      >> <[e-mail] <mailto:[e-mail]>
> >     <mailto:[e-mail] <mailto:[e-mail]>>>
> >      >      >> Cc: DetNet WG <[e-mail] <mailto:[e-mail]>
> >     <mailto:[e-mail] <mailto:[e-mail]>>>; János
> >      >     Farkas
> >      >      >> <[e-mail]
> >     <mailto:[e-mail]> <mailto:[e-mail]
> >     <mailto:[e-mail]>>>;
> >      > [e-mail] <mailto:[e-mail]>
> >     <mailto:[e-mail] <mailto:[e-mail]>>
> >      >      >> Subject: Re: [Detnet] Regarding the model for Active OAM
> >     packet
> >      >      >>
> >      >      >> Mach,
> >      >      >>
> >      >      >> If I understand you correctly this is for an LSP in an
> MPLS
> >      >     network, can you
> >      >      >> help me understand why GAL does not enough. Given that
> there
> >      >     might be
> >      >      >> some minor extensions to GAL because of replication and
> >     elimination.
> >      >      >>
> >      >      >> /Loa
> >      >      >>
> >      >      >> On 2018-09-19 14:31, Mach Chen wrote:
> >      >      >>> Hi Greg,
> >      >      >>>
> >      >      >>> Indeed, there is no DetNet Associated Channel defined in
> >      >      >>> draft-ietf-detnet-dp-sol-mpls for now, I think there
> >     should be.  I
> >      >      >>> also assume that PW ACH will be used for DetNet OAM.
> >      >      >>>
> >      >      >>> Assume that PW ACH will be used for DetNet OAM and the
> >     reserved
> >      >     filed
> >      >      >>> of the PW ACH will be used to carry sequence number for
> >     OAM packet.
> >      >      >>> But
> >      >      >>>    for PREF, a tricky way is to treat the “Version”+
> >     “Reserved” +
> >      >      >>> ”Channel type” as the Sequence number, the replication or
> >      >     elimination
> >      >      >>> nodes do not need to differentiate whether it is a d-CW
> >     or  a
> >      >     PW ACH .
> >      >      >>> This way, OAM can be supported without additional
> processing
> >      >     and states.
> >      >      >>>
> >      >      >>>          0                   1
> >      >     2                   3
> >      >      >>>
> >      >      >>>          0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3
> >     4 5 6
> >      >     7 8 9 0
> >      >      >>> 1
> >      >      >>>
> >      >      >>>
> >      >      >>>
> >     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
> >      >      >>>
> >      >      >>>         |0 0 0 1|Verion |    Reserved   |
> >     Channel Type
> >      >      >>> |
> >      >      >>>
> >      >      >>>
> >      >      >>>
> >     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
> >      >      >>>
> >      >      >>> Regarding sequence number, there are two ways to
> >     generate the
> >      >      >> sequence
> >      >      >>> number IMHO:  1) generated by the edge node, but it may
> >     need to
> >      >      >>> configure the start number, or 2) copied from the
> >      >     application-flow (if
> >      >      >>> there is). If the WG agree with this, the model can be
> >     updated
> >      >     reflect
> >      >      >>> this.
> >      >      >>>
> >      >      >>> Best regards,
> >      >      >>>
> >      >      >>> Mach
> >      >      >>>
> >      >      >>> *From:*Greg Mirsky [mailto:[e-mail]
> >     <mailto:[e-mail]>
> >      >     <mailto:[e-mail] <mailto:[e-mail]
> >>]
> >      >      >>> *Sent:* Wednesday, September 19, 2018 11:29 AM
> >      >      >>> *To:* Mach Chen <[e-mail]
> >     <mailto:[e-mail]>
> >      >     <mailto:[e-mail] <mailto:[e-mail]>>>
> >      >      >>> *Cc:* János Farkas <[e-mail]
> >     <mailto:[e-mail]>
> >      >     <mailto:[e-mail]
> >     <mailto:[e-mail]>>>; DetNet WG
> >      >      >>> <[e-mail] <mailto:[e-mail]>
> >     <mailto:[e-mail] <mailto:[e-mail]>>>;
> >      > [e-mail] <mailto:[e-mail]>
> >     <mailto:[e-mail] <mailto:[e-mail]>>
> >      >      >>> *Subject:* Re: Regarding the model for Active OAM packet
> >      >      >>>
> >      >      >>> Hi Mach,
> >      >      >>>
> >      >      >>> thank you for your attention to my comment and the most
> >     expedient
> >      >      >> response.
> >      >      >>>
> >      >      >>> I don't find the DetNet Associated Channel defined in
> >      >      >>> draft-ietf-detnet-dp-sol-mpls and thus I assumed that OAM
> >      >     packets that
> >      >      >>> follow the data packet encapsulation defined in that
> >     draft use
> >      >     PW ACH
> >      >      >>> as defined in section 5 RFC 4385: True, it includes 8
> >     bits-long
> >      >      >>> Reserved field that may be defined as OAM Sequence
> >     Number but that
> >      >      >> had
> >      >      >>> not been discussed. One is certain, existing nodes do
> >     not check the
> >      >      >>> Reserved field. And without a field to hold the sequence
> >      >     number, PREF
> >      >      >>> will not handle the OAM packets. Another question,
> >     additional
> >      >      >>> processing and amount of state introduced in the fast
> >     path by
> >      >     the fact
> >      >      >>> that OAM's Sequence Number will have different length and
> >      >     location in
> >      >      >>> d-CW (differentiating cases by the first nibble).
> >      >      >>>
> >      >      >>> Now, if we step back from DetnNet in MPLS data plane
> >     encapsulation,
> >      >      >>> why the control-word, as I understand, is configurable?
> >     I think
> >      >     that
> >      >      >>> the Sequence Number is not configurable, nor the first
> >     nibble.
> >      >     What do
> >      >      >>> you think?
> >      >      >>>
> >      >      >>> Regards,
> >      >      >>>
> >      >      >>> Greg
> >      >      >>>
> >      >      >>> On Tue, Sep 18, 2018 at 7:48 PM Mach Chen
> >     <[e-mail] <mailto:[e-mail]>
> >      >     <mailto:[e-mail] <mailto:[e-mail]>>
> >      >      >>> <mailto:[e-mail]
> >     <mailto:[e-mail]> <mailto:[e-mail]
> >     <mailto:[e-mail]>>>> wrote:
> >      >      >>>
> >      >      >>>      Hi Greg,
> >      >      >>>
> >      >      >>>      The MPLS DetNet header is defined as below:
> >      >      >>>
> >      >      >>>      grouping mpls-detnet-header {
> >      >      >>>           description
> >      >      >>>               "The MPLS DetNet encapsulation header
> >     information.";
> >      >      >>>           leaf service-label {
> >      >      >>>             type uint32;
> >      >      >>>             mandatory true;
> >      >      >>>             description
> >      >      >>>               "The service label of the DetNet header.";
> >      >      >>>           }
> >      >      >>>           leaf control-word {
> >      >      >>>             type uint32;
> >      >      >>>             mandatory true;
> >      >      >>>             description
> >      >      >>>               "The control word of the DetNet header.";
> >      >      >>>           }
> >      >      >>>         }
> >      >      >>>
> >      >      >>>      Although do not consider Active OAM when design the
> >     above
> >      >      >>>      mpls-denet-header,  seems that it can cover Active
> OAM
> >      >     case as well.
> >      >      >>>      No matter a normal DetNet packet or an Active OAM
> >     packet,
> >      >     there
> >      >      >>>      should be a CW field, just as defined above.
> >      >      >>>
> >      >      >>>      For normal DetNet packets, the CW is the d-CW as
> >     defined
> >      >     in the
> >      >      >>>      draft-ietf-detnet-dp-sol-mpls.
> >      >      >>>
> >      >      >>>      For OAM packets, the CW is the "DetNet Associated
> >     Channel".
> >      >      >>>
> >      >      >>>      Best regards,
> >      >      >>>      Mach
> >      >      >>>
> >      >      >>>
> >      >      >>>      > -----Original Message-----
> >      >      >>>      > From: detnet [mailto:[e-mail]
> >     <mailto:[e-mail]>
> >      >     <mailto:[e-mail]
> >     <mailto:[e-mail]>> <mailto:detnet- <mailto:detnet->
> >     <mailto:detnet- <mailto:detnet->>
> >      >      >> [e-mail] <mailto:[e-mail]>
> >     <mailto:[e-mail] <mailto:bounces@ietf..org>>>] On Behalf
> >      >      >>>      Of Greg Mirsky
> >      >      >>>      > Sent: Wednesday, September 19, 2018 3:17 AM
> >      >      >>>      > To: János Farkas <[e-mail]
> >     <mailto:[e-mail]>
> >      >     <mailto:[e-mail]
> >     <mailto:[e-mail]>>
> >      >      >> <mailto:[e-mail]
> >     <mailto:[e-mail]>
> >      >     <mailto:[e-mail]
> >     <mailto:[e-mail]>>>>
> >      >      >>>      > Cc: DetNet WG <[e-mail]
> >     <mailto:[e-mail]> <mailto:[e-mail]
> >     <mailto:[e-mail]>>
> >      >     <mailto:[e-mail] <mailto:[e-mail]>
> >     <mailto:[e-mail] <mailto:[e-mail]>>>>; detnet-
> >      >      >> [e-mail] <mailto:[e-mail]>
> >     <mailto:[e-mail] <mailto:[e-mail]>>
> >      >      >>>      <mailto:[e-mail]
> >     <mailto:[e-mail]>
> >      >     <mailto:[e-mail] <mailto:[e-mail]
> >>>
> >      >      >>>      > Subject: Re: [Detnet] WG adoption poll
> >      >     draft-geng-detnet-conf-yang
> >      >      >>>      >
> >      >      >>>      > Hi Janos, et.. al,
> >      >      >>>      > the mpls-detnet-header container is based on the
> >      >     solution described in
> >      >      >>>      > draft-ietf-detnet-dp-sol-mpls. Analysis of active
> SFC
> >      >     OAM in the
> >      >      >> proposed
> >      >      >>>      > MPLS data plane solution in
> draft-mirsky-detnet-oam
> >      >     points to the
> >      >      >> potential
> >      >      >>>      > problem as result the fact that OAM packet doesn't
> >      >     include d-CW. I
> >      >      >> believe
> >      >      >>>      > that this question should be discussed and, if we
> >     agree
> >      >     on the problem
> >      >      >>>      > statement, properly resolved. Until then, I do not
> >      >     support the adoption
> >      >      >> of
> >      >      >>>      > the model that may not be capable to support
> >     active OAM.
> >      >      >>>      >
> >      >      >>>      > Regards,
> >      >      >>>      > Greg
> >      >      >>>      > On Tue, Sep 18, 2018 at 12:03 PM Janos Farkas
> >      >      >> <[e-mail]
> >     <mailto:[e-mail]> <mailto:[e-mail]
> >     <mailto:[e-mail]>>
> >      >     <mailto:[e-mail]
> >     <mailto:[e-mail]> <mailto:[e-mail]
> >     <mailto:[e-mail]>>>>
> >      >      >>>      > wrote:
> >      >      >>>      > >
> >      >      >>>      > > Dear all,
> >      >      >>>      > >
> >      >      >>>      > > This is start of a two week poll on making
> >      >      >>>      > > draft-geng-detnet-conf-yang-04 a working group
> >      >     document. Please
> >      >      >> send
> >      >      >>>      > > email to the list indicating "yes/support" or
> >     "no/do
> >      >     not support".  If
> >      >      >>>      > > indicating no, please state your reservations
> >     with the
> >      >     document.  If
> >      >      >>>      > > yes, please also feel free to provide comments
> >     you'd
> >      >     like to see
> >      >      >>>      > > addressed once the document is a WG document.
> >      >      >>>      > >
> >      >      >>>      > > The poll ends Oct 3.
> >      >      >>>      > >
> >      >      >>>      > > Thanks,
> >      >      >>>      > > János and Lou
> >      >      >>>      > >
> >      >      >>>      > > _______________________________________________
> >      >      >>>      > > detnet mailing list
> >      >      >>>      > > [e-mail] <mailto:[e-mail]>
> >     <mailto:[e-mail] <mailto:[e-mail]>>
> >      >     <mailto:[e-mail] <mailto:[e-mail]>
> >     <mailto:[e-mail] <mailto:[e-mail]>>>
> >      >      >>>      > > https://www.ietf.org/mailman/listinfo/detnet
> >      >      >>>      >
> >      >      >>>      > _______________________________________________
> >      >      >>>      > detnet mailing list
> >      >      >>>      > [e-mail] <mailto:[e-mail]>
> >     <mailto:[e-mail] <mailto:[e-mail]>>
> >      >     <mailto:[e-mail] <mailto:[e-mail]>
> >     <mailto:[e-mail] <mailto:[e-mail]>>>
> >      >      >>>      > https://www.ietf.org/mailman/listinfo/detnet
> >      >      >>>
> >      >      >>>
> >      >      >>>
> >      >      >>> _______________________________________________
> >      >      >>> detnet mailing list
> >      >      >>> [e-mail] <mailto:[e-mail]>
> >     <mailto:[e-mail] <mailto:[e-mail]>>
> >      >      >>> https://www.ietf.org/mailman/listinfo/detnet
> >      >      >>>
> >      >      >>
> >      >      >> --
> >      >      >>
> >      >      >>
> >      >      >> Loa Andersson                        email: [e-mail]
> >     <mailto:[e-mail]>
> >      >     <mailto:[e-mail] <mailto:[e-mail]>>
> >      >      >> Senior MPLS Expert
> >      >      >> Bronze Dragon Consulting             phone: [phone]
> 64
> >      >      >>
> >      >      >> _______________________________________________
> >      >      >> detnet mailing list
> >      >      >> [e-mail] <mailto:[e-mail]>
> >     <mailto:[e-mail] <mailto:[e-mail]>>
> >      >      >> https://www.ietf.org/mailman/listinfo/detnet
> >      >      > _______________________________________________
> >      >      > detnet mailing list
> >      >      > [e-mail] <mailto:[e-mail]>
> >     <mailto:[e-mail] <mailto:[e-mail]>>
> >      >      > https://www.ietf.org/mailman/listinfo/detnet
> >      >      >
> >      >
> >      >     --
> >      >
> >      >
> >      >     Loa Andersson                        email: [e-mail]
> >     <mailto:[e-mail]> <mailto:[e-mail] <mailto:[e-mail]>>
> >      >     Senior MPLS Expert
> >      >     Bronze Dragon Consulting             phone: [phone]
> >      >
> >
> >     --
> >
> >
> >     Loa Andersson                        email: [e-mail] <mailto:
> [e-mail]>
> >     Senior MPLS Expert
> >     Bronze Dragon Consulting             phone: [phone]
> >
> >
> >
> > _______________________________________________
> > detnet mailing list
> > [e-mail]
> > https://www.ietf.org/mailman/listinfo/detnet
> >
>
> --
>
>
> Loa Andersson                        email: [e-mail]
> Senior MPLS Expert
> Bronze Dragon Consulting             phone: [phone]
>