Hi Tom,
I'll let Frank answer your question as it is on iOAM, not OOAM.

Regards,
Greg

On Thu, Apr 12, 2018 at 11:53 PM, Tom Herbert <t...@herbertland.com> wrote:

> On Thu, Apr 12, 2018 at 2:50 PM, Greg Mirsky <gregimir...@gmail.com>
> wrote:
> > Hi Tom,
> > could you please mention which drafts, iOAM or OOAM, you refer to. Please
> > note, that OOAM supports both active and hybrid OAM methods, while iOAM
> only
> > the latter.
>
> Section 3 of draft-brockners-ippm-ioam-geneve-00 for instance.
>
> >
> > Regards,
> > Greg
> >
> > On Thu, Apr 12, 2018 at 11:46 PM, Tom Herbert <t...@herbertland.com>
> wrote:
> >>
> >> On Thu, Apr 12, 2018 at 9:54 AM, Greg Mirsky <gregimir...@gmail.com>
> >> wrote:
> >> > Hi Frank,
> >> > thank you for sharing your points. Please find my notes in-line and
> >> > tagged
> >> > GIM>>. I believe that this is very much relevant to work of other
> >> > working
> >> > groups that directly work on the overlay encapsulations in the center
> of
> >> > the
> >> > discussion and hence I've added them to the list. Hope we'll have more
> >> > opinions to reach the conclusion that is acceptable to all.
> >> >
> >> > Regards,
> >> > Greg
> >> >
> >> > On Wed, Apr 11, 2018 at 12:02 PM, Frank Brockners (fbrockne)
> >> > <fbroc...@cisco.com> wrote:
> >> >>
> >> >> Back at the IPPM meeting in London, we discussed several drafts
> dealing
> >> >> with the encapsulation of IOAM data in various protocols
> >> >> (draft-brockners-ippm-ioam-vxlan-gpe-00,
> >> >> draft-brockners-ippm-ioam-geneve-00, draft-weis-ippm-ioam-gre-00).
> One
> >> >> discussion topic that we decided to take to the list was the question
> >> >> on
> >> >> whether draft-ooamdt-rtgwg-ooam-header could be leveraged.  After
> >> >> carefully
> >> >> considering draft-ooamdt-rtgwg-ooam-header, I came to the conclusion
> >> >> that
> >> >> the “OOAM header” does not meet the needs of IOAM:
> >> >>
> >> >> * Efficiency: IOAM adds data to live user traffic. As such, an
> >> >> encapsulation needs to be as efficient as possible. The “OOAM header”
> >> >> is 8
> >> >> bytes long. The approach for IOAM data encapsulation in the above
> >> >> mentioned
> >> >> drafts only requires 4 bytes. Using the OOAM header approach would
> add
> >> >> an
> >> >> unnecessary overhead of 4 bytes – which is significant.
> >> Greg,
> >>
> >> I'm missing something here. I looked at the drafts you referenced and
> >> each of them looks like the overhead for OAM is greater that four
> >> bytes. In each there is some overhead equivalent to type/length, for
> >> instance in Geneve four bytes are needed for option class, type, and
> >> length. Unless the the OAM data is zero length, I don't see how this
> >> adds up to only four bytes of overhead.
> >>
> >> Tom
> >>
> >> >
> >> > GIM>> The difference in four octets is because OOAM Header:
> >> >
> >> > provides more flexibility, e.g. Flags field and Reserved fields;
> >> > supports larger OAM packets than iOAM header;
> >> > is future proof by supporting versioning (Version field).
> >> >>
> >> >> * Maturity: IOAM has several implementations, which were also shown
> at
> >> >> recent IETF hackathons – and we’re expecting additional
> implementations
> >> >> to
> >> >> be publicized soon. Interoperable implementations need timely
> >> >> specifications. Despite the question being asked, the recent thread
> on
> >> >> OOAM
> >> >> in the NVO3 list hasn’t revealed any implementation of the OOAM
> header.
> >> >> In
> >> >> addition, the thread revealed that several fundamental questions
> about
> >> >> the
> >> >> OOAM header are still open, such as whether or how active OAM
> >> >> mechanisms
> >> >> within protocols such as Geneve would apply to the OOAM header. This
> >> >> ultimately means that we won’t get to a timely specification.
> >> >
> >> > GIM>> May I ask which encapsulations supported by the implementations
> >> > you
> >> > refer to. Until very recently all iOAM proposals were to use meta-data
> >> > TLV
> >> > in, e.g. Geneve and NSH. And if these or some of these implementations
> >> > already updated to the newly proposed iOAM shim, I don't see problem
> in
> >> > making them use OOAM Header. Would you agree?
> >> >
> >> >>
> >> >> * Scope: It isn’t entirely clear to which protocols the OOAM header
> >> >> would
> >> >> ultimately apply to. The way the OOAM header is defined, OOAM uses a
> >> >> 8-bit
> >> >> field for “Next Prot”, the next protocol. Some protocols that IOAM
> data
> >> >> needs to be encapsulated into use 16-bits for their next protocol
> code
> >> >> points. See e.g. the GRE encapsulation – as specified in
> >> >> draft-weis-ippm-ioam-gre-00.
> >> >
> >> > GIM>> The first paragraph of the Introduction section states:
> >> >    New protocols that support overlay networks like VxLAN-GPE
> >> >    [I-D.ietf-nvo3-vxlan-gpe], GUE [I-D.ietf-nvo3-gue], Geneve
> >> >    [I-D.ietf-nvo3-geneve], BIER [I-D.ietf-bier-mpls-encapsulation],
> and
> >> >    NSH [I-D.ietf-sfc-nsh] support multi-protocol payload, e.g.
> >> >    Ethernet, IPv4/IPv6, and recognize Operations, Administration, and
> >> >    Maintenance (OAM) as one of distinct types.  That ensures that
> >> >    Overlay OAM (OOAM)packets are sharing fate with Overlay data packet
> >> >    traversing the underlay.
> >> > I'm updating the OOAM Header draft and along with cleaning nits will
> >> > update
> >> > reference to GUE. I think that the list and the statemnt are quite
> clear
> >> > in
> >> > identifying the scope of networks that may benefit from using not only
> >> > common OOAM Header but common OOAM mechanisms, e.g. Echo
> Request/Reply.
> >> >
> >> >> With the above in mind, I’d suggest that the WG moves forward with
> >> >> specific definitions for encapsulating IOAM data into protocols – per
> >> >> the
> >> >> above mentioned drafts.
> >> >>
> >> >>
> >> >>
> >> >> Regards, Frank
> >> >>
> >> >>
> >> >> _______________________________________________
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> >> >> i...@ietf.org
> >> >> https://www.ietf.org/mailman/listinfo/ippm
> >> >>
> >> >
> >> >
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> >> >
> >
> >
>
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