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

[Loa Andersson <[e-mail]>]

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]
>      >      >>
>      >      >> _______________________________________________
>      >      >> 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]