Re: [ippm] [sfc] WGLC for https://datatracker.ietf.org/doc/draft-ietf-sfc-ioam-nsh/

[Shwetha Bhandari <[e-mail]>]

Med,

Thanks for the details: this is exactly what we had before the latest
revision:

4.2 <https://datatracker.ietf.org/doc/html/draft-ietf-sfc-ioam-nsh-06#section-4.2>.
IOAM and the use of the NSH O-bit

   [RFC8300] defines an "O bit" for OAM packets.  Per [RFC8300
<https://datatracker.ietf.org/doc/html/rfc8300>] the O
   bit must be set for OAM packets and must not be set for non-OAM
   packets.  Packets with IOAM data included MUST follow this
   definition, i.e. the O bit MUST NOT be set for regular customer
   traffic which also carries IOAM data and the O bit MUST be set for
   OAM packets which carry only IOAM data without any regular data
   payload.


This was removed as per the discussion in this thread. Please check
https://mailarchive.ietf.org/arch/msg/sfc/srMit5zE8UseNOhxknAw_dqvj6M/

It looks like we are going in a loop here. This definition of SFC OAM
packet to include the OAM data that comes in inner packets via the next
protocol header chain is introduced in draft-ietf-sfc-oam-packet to update
the RFC8300.
Jim, What are you thoughts on this? Should we reintroduce the above text ?

Thanks,
Shwetha



On Tue, Apr 12, 2022 at 8:09 PM <[e-mail]> wrote:

> Hi Franck,
>
>
>
> Thank you for the clarification even if I don’t think there is a
> confusion.
>
>
>
> Please note that SFC OAM packet is defined as follows:
>
>
>
> ==
>
>       Such a packet
>
>       is any NSH-encapsulated packet that exclusively includes OAM data.
>
>       An OAM data can be included in the Fixed-Length Context Header,
>
>       optional Context Headers, and/or the inner packet.
>
> ==
>
>
>
> Things are pretty clear (as per draft-ietf-sfc-oam-packet) that the O bit
> must be unset when IOAM data is included + user data.
>
>
>
> The concern I had is that you are pointing to RFC8300 for the IOAM next
> protocol, which makes both “none” (i.e., no payload) and IOAM (as you
> request a new code) legitimate values.
>
>
>
> Cheers,
>
> Med
>
>
>
> *De :* sfc <[e-mail]> *De la part de* Frank Brockners
> (fbrockne)
> *Envoyé :* mardi 12 avril 2022 13:55
> *À :* BOUCADAIR Mohamed INNOV/NET <[e-mail]>; Shwetha
> Bhandari <[e-mail]>; Greg Mirsky <
> [e-mail]>
> *Cc :* [e-mail]; [e-mail]; [e-mail]; James Guichard <
> [e-mail]>; Tal Mizrahi <[e-mail]>;
> [e-mail]
> *Objet :* Re: [sfc] WGLC for
> https://datatracker.ietf.org/doc/draft-ietf-sfc-ioam-nsh/
> <https://urldefense.com/v3/__https://datatracker.ietf.org/doc/draft-ietf-sfc-ioam-nsh/__;!!MZ3Fw45to5uY!JpBZ4H2-MNm5lJDGjooVj_3Sq-aX7gdh5qeoNPyZ69CXOFRhgdYmSOyreClzKvZDgPAiwaGN2YTO2qUw70GqHI4QEKQpGnBw0LXBXQ$>
>
>
>
> Hi Med,
>
>
>
> Sorry for arriving late to the party. Reading through your message below,
> there seems to be a confusion about the scope and concept of different OAM
> mechanisms.
>
>
>
> IOAM is scoped and designed to be protocol agnostic. IOAM data can be
> encapsulated into various protocols – and NSH is one example – but there is
> no semantic link between IOAM and the protocol used to encapsulate IOAM
> data.
>
>
>
> Protocols can have their protocol specific OAM methods and solutions, like
> SFC OAM. Those protocol specific solutions (like SFC OAM as an example) are
> orthogonal to IOAM from a concept and scope perspective.
>
>
>
> From an SFC OAM perspective, your draft-ietf-sfc-oam-packet-00 clearly and
> rightly states that “O bit: Setting this bit indicates an SFC OAM packet.”
> The O bit is about SFC OAM, and as such is orthogonal to “anything IOAM”.
> In earlier versions of draft-ietf-sfc-ioam-nsh we had text which stated
> that the O bit remains unchanged whether IOAM is present or not. To avoid
> any confusion, in -08 we removed this statement – just to make it crystal
> clear that there is no link between “IOAM” and “SFC OAM”.
>
>
>
> In addition, I don’t think that draft-ietf-sfc-ioam-nsh would be the
> appropriate place to discuss and restrict deployment options. E.g., I’m not
> sure why we’d want to restrict a deployment to using a single IOAM header
> only. E.g., one could think of using different headers for different
> namespaces or groups of namespaces for operational reasons. IMHO, such a
> discussion – if we really need it - would belong into
> draft-ietf-ippm-ioam-deployment, rather than into a draft that defines the
> encap of IOAM into NSH.
>
>
>
> Hope this clarifies things – and we can finish up draft-ietf-sfc-ioam-nsh
> :-).
>
>
>
> Cc’ing the ippm working group as an FYI.
>
>
>
> Thanks & Cheers, Frank
>
>
>
>
>
>
>
> *From:* [e-mail] <[e-mail]>
> *Sent:* Monday, 4 April 2022 07:40
> *To:* Shwetha Bhandari <[e-mail]>; Greg Mirsky <
> [e-mail]>
> *Cc:* [e-mail]; Frank Brockners (fbrockne) <[e-mail]>;
> [e-mail]; James Guichard <[e-mail]>; Tal
> Mizrahi <[e-mail]>; [e-mail]
> *Subject:* RE: [sfc] WGLC for
> https://datatracker.ietf.org/doc/draft-ietf-sfc-ioam-nsh/
> <https://urldefense.com/v3/__https://datatracker.ietf.org/doc/draft-ietf-sfc-ioam-nsh/__;!!MZ3Fw45to5uY!JpBZ4H2-MNm5lJDGjooVj_3Sq-aX7gdh5qeoNPyZ69CXOFRhgdYmSOyreClzKvZDgPAiwaGN2YTO2qUw70GqHI4QEKQpGnBw0LXBXQ$>
>
>
>
> Hi Shwetha, all,
>
>
>
> I agree with Greg that a statement is needed to be added to
> draft-ietf-sfc-oam-packet.
>
>
>
> For example, the current text says the following:
>
>
>
>       Next Protocol:  8-bit unsigned integer that determines the type of
>
>          header following IOAM.  The semantics of this field are
>
>          identical to the Next Protocol field in [RFC8300
> <https://urldefense.com/v3/__https://datatracker.ietf.org/doc/html/rfc8300__;!!MZ3Fw45to5uY!JpBZ4H2-MNm5lJDGjooVj_3Sq-aX7gdh5qeoNPyZ69CXOFRhgdYmSOyreClzKvZDgPAiwaGN2YTO2qUw70GqHI4QEKQpGnDoYxXlRw$>
> ].
>
>
>
> which means that “None” is authorized. The O-bit must be set for such
> packets, while it should be unset for other values indicating user payload
> as per draft-ietf-sfc-oam-packet. Absent a pointer to the OAM packet, an
> implementer will have to guess the behavior to follow.
>
>
>
> BTW, the text quoted above when combined with:
>
>
>
>    IANA is requested to allocate protocol numbers for the following "NSH
>
>    Next Protocol" related to IOAM:
>
>
>
> …means that IOAM data can be encapsulated in IOAM data. I don’t think you
> want such a behavior. No?
>
>
>
> One last comment: please update the security considerations with
> NSH-specific considerations. An approach is to simply refer to Section 5 of
> draft-ietf-sfc-oam-packet.
>
>
>
> Cheers,
>
> Med
>
>
>
> *De :* sfc <[e-mail]> *De la part de* Shwetha Bhandari
> *Envoyé :* lundi 4 avril 2022 02:41
> *À :* Greg Mirsky <[e-mail]>
> *Cc :* [e-mail]; Frank Brockners (fbrockne) <[e-mail]>;
> [e-mail]; James Guichard <[e-mail]>; Tal
> Mizrahi <[e-mail]>; [e-mail]
> *Objet :* Re: [sfc] WGLC for
> https://datatracker.ietf.org/doc/draft-ietf-sfc-ioam-nsh/
> <https://urldefense.com/v3/__https://datatracker.ietf.org/doc/draft-ietf-sfc-ioam-nsh/__;!!MZ3Fw45to5uY!JpBZ4H2-MNm5lJDGjooVj_3Sq-aX7gdh5qeoNPyZ69CXOFRhgdYmSOyreClzKvZDgPAiwaGN2YTO2qUw70GqHI4QEKQpGnBw0LXBXQ$>
>
>
>
> Hi Greg,
>
>
>
> Thanks for the feedback. From the discussion and Jim's feedback
>
>  "My only point was that in the case of IOAM the O-bit seems to be
> obsolete as you use the next protocol field rather than the context
> headers. It seems to me that the definition of the O-bit should be that if
> set then the context headers are used to obtain the OAM instructions."
>
> Which makes sense. The O-bit does not influence IOAM handling as it is
> carried as a next protocol.
>
> Hence the consideration section on O-bit is removed in the new revision.
> What do you think?
>
>
>
> Thanks
>
> Shwetha
>
>
>
> On Mon, Apr 4, 2022, 1:41 AM Greg Mirsky <[e-mail]> wrote:
>
> Hi Shwetha,
>
> thank you for your kind consideration of my comments and for
> thoroughly addressing those in the new version. I've noticed that you've
> decided to remove the discussion of the O bit in the NSH from the draft
> altogether. I think that it might be helpful to a reader if the document
> includes a short clarification and the reference to
> draft-ietf-sfc-oam-packet
> <https://urldefense.com/v3/__https:/www.ietf.org/id/draft-ietf-sfc-oam-packet-00.html__;!!MZ3Fw45to5uY!JYVtUwScRxFf7rDoRMpiv7YwbRTcaHXzsGIxr9eVEi_p_xSQUWAjDvFy_UhGEQbl8530VaLM0Tj7k5Wzu6YfUSVditWyZ_8$> like
> the following:
>
> For the IOAM functionality is SFC NSH described in this document the O bit
>
> in NSH MUST be set clear according to [I-D.ietf-sfc-oam-packet].
>
>
>
> Regards,
>
> Greg
>
>
>
> On Sun, Apr 3, 2022 at 1:06 AM Shwetha Bhandari <
> [e-mail]> wrote:
>
> Hi Jim, Greg,
>
>
>
> We have addressed the additional comments received in this discussion. Can
> you please take a look :
>
> https://www.ietf.org/rfcdiff?url2=draft-ietf-sfc-ioam-nsh-08.txt
> <https://urldefense.com/v3/__https:/www.ietf.org/rfcdiff?url2=draft-ietf-sfc-ioam-nsh-08.txt__;!!MZ3Fw45to5uY!JYVtUwScRxFf7rDoRMpiv7YwbRTcaHXzsGIxr9eVEi_p_xSQUWAjDvFy_UhGEQbl8530VaLM0Tj7k5Wzu6YfUSVd4KRpUCA$>
>
>
>
> Thanks,
>
> Shwetha
>
>
>
> On Thu, Feb 10, 2022 at 11:27 PM James Guichard <
> [e-mail]> wrote:
>
> Hi Shwetha,
>
>
>
> My only point was that in the case of IOAM the O-bit seems to be obsolete
> as you use the next protocol field rather than the context headers. It
> seems to me that the definition of the O-bit should be that if set then the
> context headers are used to obtain the OAM instructions. Currently that is
> not what 8300 says. As I said in my previous emails I would really like to
> hear the WGs opinion on what to do with the O-bit and we certainly need to
> reconcile the various documents to be following the same standard.
>
>
>
> Jim
>
>
>
> *From:* Shwetha Bhandari <[e-mail]>
> *Sent:* Wednesday, February 9, 2022 9:57 AM
> *To:* Greg Mirsky <[e-mail]>
> *Cc:* James Guichard <[e-mail]>;
> [e-mail]; [e-mail]; [e-mail]
> *Subject:* Re: [sfc] WGLC for
> https://datatracker.ietf.org/doc/draft-ietf-sfc-ioam-nsh/
> <https://urldefense.com/v3/__https:/datatracker.ietf.org/doc/draft-ietf-sfc-ioam-nsh/__;!!MZ3Fw45to5uY!f5SSgs9VAH1xxjFWgJMfr5ZlZH93z6GJlXoOgCmY8AVbjdeh2YlaUz632nE-HqDItW_8pjQ1iQ$>
>
>
>
> Hi Jim,
>
>
>
> On the O bit handling, are you suggesting that the O-bit for IOAM, that is
> carried as a next protocol following NSH header, is not applicable? Would
> removing the section on O-bit considerations resolve your concern?
>
>
>
> Hi Greg,
>
>
>
> >I have one more question. As the draft now mentions the option of using
> IOAM Direct Export to collect the IOAM data, it might be helpful reflecting
> that in the figure on p.2. I think that the caption "IOAM Option and Data
> Space" might be reworded to "IOAM Option and Optional Data Space".
>
> What are your thoughts?
>
> Yes, that will make it accurate. I will update the diagram and publish a
> new version.
>
>
>
> >I cannot find the text in the draft suggesting that an SFF that does not
> support IOAM may forward the packet with the NSH Next Protocol field equal
> to IOAM protocol identifier. Could you help me find it?
>
> Can you suggest text to help with this ? This would be a generic problem
> for NSH implementation when a next protocol is set to a value it does not
> understand. What should is recommended action in this situation?
>
>
>
>
>
> > For example, if the Loopback IOAM flag is set, the node is required to
> send a copy of the packet back to the IOAM encapsulating node. It is not
> clear to me how an SFF learns the identity of the IOAM encapsulating node
> and how it encapsulates the loopbacked packet. Can you help me find how it
> is supposed to work in the NSH?
>
>
> https://datatracker.ietf.org/doc/html/draft-ietf-ippm-ioam-flags#section-4.2
> <https://urldefense.com/v3/__https:/nam11.safelinks.protection.outlook.com/?url=https*3A*2F*2Fdatatracker.ietf.org*2Fdoc*2Fhtml*2Fdraft-ietf-ippm-ioam-flags*23section-4.2&data=04*7C01*7Cjames.n.guichard*40futurewei.com*7Ca5db82494c32402334fc08d9ebdc83cf*7C0fee8ff2a3b240189c753a1d5591fedc*7C1*7C0*7C637800154631120774*7CUnknown*7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0*3D*7C3000&sdata=zcOpC0Gzzi8xzhttBqWaeaU3pMd0KDo*2FZYdGsEPG0uE*3D&reserved=0__;JSUlJSUlJSUlJSUlJSUlJSUlJSUl!!MZ3Fw45to5uY!f5SSgs9VAH1xxjFWgJMfr5ZlZH93z6GJlXoOgCmY8AVbjdeh2YlaUz632nE-HqDItW_cH_6kAg$>
> :
>
>   A Loopback flag that is set indicates to the transit nodes processing
>
>    this option that they are to create a copy of the received packet and
>
>    send the copy back to the source of the packet.
>
> Given this is explained in the flag handling, do you see a need to define
> it again in NSH? IMHO the explanation of flag handling is quite generic for
> any packet based transport.
>
> Please share your thoughts and text suggestions to improve the draft for
> flag handling if it requires clarification.
>
>
>
>
>
> Thanks,
>
> Shwetha
>
>
>
> On Thu, Feb 3, 2022 at 6:48 AM Greg Mirsky <[e-mail]> wrote:
>
> Hi Shwetha,
>
> I have one more question. As the draft now mentions the option of using
> IOAM Direct Export to collect the IOAM data, it might be helpful reflecting
> that in the figure on p.2. I think that the caption "IOAM Option and Data
> Space" might be reworded to "IOAM Option and Optional Data Space".
>
> What are your thoughts?
>
>
>
> Regards,
>
> Greg
>
>
>
> On Wed, Feb 2, 2022 at 7:29 AM Shwetha Bhandari <
> [e-mail]> wrote:
>
> Hi Jim, Greg,
>
>
>
> Thanks for the follow up.
>
> 1) On O-bit: I am a bit confused about the O-bit feedback. Are you
> suggesting that it should not be a consideration for IOAM as it is handled
> as a next protocol and not as NSH context headers?
>
> What should a SFC element handle a packet containing IOAM as next header
> and does not implement IOAM and hence does not understand IOAM? I think
> O-bit helps in such situations to help such elements decide to drop or
> forward without processing the IOAM header.
>
> Let me know if that is not the case and if simply not considering O-bit in
> the context of IOAM is what you would recommend.
>
> 2) Active or Loopback flags
> <https://urldefense.com/v3/__https:/nam11.safelinks.protection.outlook.com/?url=https*3A*2F*2Furldefense.com*2Fv3*2F__https*3A*2F*2Fdatatracker.ietf.org*2Fdoc*2Fdraft-ietf-ippm-ioam-flags*2F__*3B!!MZ3Fw45to5uY!eu05ObEvXtnVX2OXFzl0g16vk36xSqTyjMReG_i6BavtG_ru2AnjQSjXHiZ_Ve3sBjJRuHMBUg*24&data=04*7C01*7Cjames.n.guichard*40futurewei.com*7Ca5db82494c32402334fc08d9ebdc83cf*7C0fee8ff2a3b240189c753a1d5591fedc*7C1*7C0*7C637800154631277005*7CUnknown*7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0*3D*7C3000&sdata=DvpZHlkn0PNCP5*2BzFQzGayutZGPUMxJXtPll6nR8Ay8*3D&reserved=0__;JSUlJSUlJSUlJSUlJSUlJSUlJSUlJSUlJSUl!!MZ3Fw45to5uY!f5SSgs9VAH1xxjFWgJMfr5ZlZH93z6GJlXoOgCmY8AVbjdeh2YlaUz632nE-HqDItW_4eduZWg$> -
> there is nothing specific for NSH on how the flags are to be handled.  The
> IOAM specific fields are to be handled as recommended by the respective
> IOAM drafts. Do you see any specific NSH considerations to be documented
> for IOAM fields?
>
>
>
> Thanks,
>
> Shwetha
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
> On Tue, Feb 1, 2022 at 4:29 PM James Guichard <
> [e-mail]> wrote:
>
> Hi Shwetha & Greg,
>
>
>
> Thank you for the update.
>
>
>
> I still believe however that more work is necessary to reconcile how SFC
> OAM is supposed to work. RFC 8300 says:
>
>
>
>    O bit:  Setting this bit indicates an OAM packet (see [RFC6291
> <https://urldefense.com/v3/__https:/nam11.safelinks.protection.outlook.com/?url=https*3A*2F*2Furldefense.com*2Fv3*2F__https*3A*2F*2Fdatatracker.ietf.org*2Fdoc*2Fhtml*2Frfc6291__*3B!!MZ3Fw45to5uY!bzL7Vb_jHltGMCbCwne2rywfzpGjZW4o3fVr4clCr4Ir10KydDyJy5gHA8obfbMABJs06rKUNw*24&data=04*7C01*7Cjames.n.guichard*40futurewei.com*7Ca5db82494c32402334fc08d9ebdc83cf*7C0fee8ff2a3b240189c753a1d5591fedc*7C1*7C0*7C637800154631277005*7CUnknown*7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0*3D*7C3000&sdata=4wRcNgj93har9TlylAfX*2BtbW24VCqfneSZd0rD9CRzs*3D&reserved=0__;JSUlJSUlJSUlJSUlJSUlJSUlJSUlJSUlJSUl!!MZ3Fw45to5uY!f5SSgs9VAH1xxjFWgJMfr5ZlZH93z6GJlXoOgCmY8AVbjdeh2YlaUz632nE-HqDItW8b5uw-Yg$>
> ]).
>
>       The actual format and processing of SFC OAM packets is outside the
>
>       scope of this specification (for example, see [SFC-OAM-FRAMEWORK
> <https://urldefense.com/v3/__https:/nam11.safelinks.protection.outlook.com/?url=https*3A*2F*2Furldefense.com*2Fv3*2F__https*3A*2F*2Fdatatracker.ietf.org*2Fdoc*2Fhtml*2Frfc8300*ref-SFC-OAM-FRAMEWORK__*3BIw!!MZ3Fw45to5uY!bzL7Vb_jHltGMCbCwne2rywfzpGjZW4o3fVr4clCr4Ir10KydDyJy5gHA8obfbMABJsisioAug*24&data=04*7C01*7Cjames.n.guichard*40futurewei.com*7Ca5db82494c32402334fc08d9ebdc83cf*7C0fee8ff2a3b240189c753a1d5591fedc*7C1*7C0*7C637800154631277005*7CUnknown*7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0*3D*7C3000&sdata=A6fkAO8CwRJeW5tLLEpU0GhZrqsBOm7nUiE1QiMxwVQ*3D&reserved=0__;JSUlJSUlJSUlJSUqJSUlJSUlJSUlJSUlJSUl!!MZ3Fw45to5uY!f5SSgs9VAH1xxjFWgJMfr5ZlZH93z6GJlXoOgCmY8AVbjdeh2YlaUz632nE-HqDItW_b7k_TUA$>
> ]
>
>       for one approach).
>
>
>
>       The O bit MUST be set for OAM packets and MUST NOT be set for
>
>       non-OAM packets.
>
>
>
> If we look at RFC6291 it simply describes what OAM is supposed to mean and
> this is independent from SFC. The SFC-OAM-Framework (now RFC 8924) in
> section 6.3 says:
>
>
>
>    The Next Protocol field in the NSH header may be used to indicate what
> OAM function is intended
>
>    or what toolset is used.  Any other overlay encapsulations used at the
> service layer must have a
>
>    similar way to indicate the intended OAM function.
>
>
>
> So my reading of this is that if you take 8300 together with the framework
> then 1. The O-bit MUST be set for OAM packets, and 2. The Next Protocol
> field may or may not be used to indicate which OAM function is to be
> applied. From this I can determine that iOAM has taken the approach of
> using the next protocol field to indicate how to process the OAM packet and
> does NOT use the NSH context headers in any way shape or form. This seems
> consistent with the current definitions of the O-bit from RFC 8300 and
> processing guidelines from RFC 8924.
>
>
>
> However, your document says:
>
>
>
> *4.1
> <https://urldefense.com/v3/__https:/nam11.safelinks.protection.outlook.com/?url=https*3A*2F*2Furldefense.com*2Fv3*2F__https*3A*2F*2Fdatatracker.ietf.org*2Fdoc*2Fhtml*2Fdraft-ietf-sfc-ioam-nsh-07*section-4.1__*3BIw!!MZ3Fw45to5uY!bzL7Vb_jHltGMCbCwne2rywfzpGjZW4o3fVr4clCr4Ir10KydDyJy5gHA8obfbMABJtXMLMQUw*24&data=04*7C01*7Cjames.n.guichard*40futurewei.com*7Ca5db82494c32402334fc08d9ebdc83cf*7C0fee8ff2a3b240189c753a1d5591fedc*7C1*7C0*7C637800154631277005*7CUnknown*7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0*3D*7C3000&sdata=w3hANsqqvVWz5oeH*2BLfPwS*2Fxwh2hNERJwCw5zwdrAMA*3D&reserved=0__;JSUlJSUlJSUlJSUqJSUlJSUlJSUlJSUlJSUlJSU!!MZ3Fw45to5uY!f5SSgs9VAH1xxjFWgJMfr5ZlZH93z6GJlXoOgCmY8AVbjdeh2YlaUz632nE-HqDItW9Fp7_C8w$>.
> IOAM and the use of the NSH O-bit*
>
>
>
>    [RFC8300] defines an "O bit" for OAM packets.  Per [RFC8300
> <https://urldefense.com/v3/__https:/nam11.safelinks.protection.outlook.com/?url=https*3A*2F*2Furldefense.com*2Fv3*2F__https*3A*2F*2Fdatatracker.ietf.org*2Fdoc*2Fhtml*2Frfc8300__*3B!!MZ3Fw45to5uY!bzL7Vb_jHltGMCbCwne2rywfzpGjZW4o3fVr4clCr4Ir10KydDyJy5gHA8obfbMABJuMIrqXAQ*24&data=04*7C01*7Cjames.n.guichard*40futurewei.com*7Ca5db82494c32402334fc08d9ebdc83cf*7C0fee8ff2a3b240189c753a1d5591fedc*7C1*7C0*7C637800154631277005*7CUnknown*7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0*3D*7C3000&sdata=a*2BVevL6noSzqRzdWg6dscjiqevlLbxcgEdTEmfJAY7U*3D&reserved=0__;JSUlJSUlJSUlJSUlJSUlJSUlJSUlJSUlJSUl!!MZ3Fw45to5uY!f5SSgs9VAH1xxjFWgJMfr5ZlZH93z6GJlXoOgCmY8AVbjdeh2YlaUz632nE-HqDItW92fQLzlQ$>]
> the O
>
>    bit must be set for OAM packets and must not be set for non-OAM
>
>    packets.  Packets with IOAM data included MUST follow this
>
>    definition, i.e. the O bit MUST NOT be set for regular customer
>
>    traffic which also carries IOAM data and the O bit MUST be set for
>
>    OAM packets which carry only IOAM data without any regular data
>
>    payload.
>
>
>
> This text basically says that if the packet is customer traffic and
> happens to carry iOAM data then it is NOT an OAM packet.  What am I
> missing, customer traffic or not, both carry iOAM data so how are they
> different within an SFC domain?
>
>
>
> In addition to the above I will note that there is still a conflict with
> Greg’s draft namely this text from section 4:
>
>    *  O bit set and the "Next Protocol" value does not match the value
>
>       Active SFC OAM (TBA1), defined in Section 10.1
> <https://urldefense.com/v3/__https:/nam11.safelinks.protection.outlook.com/?url=https*3A*2F*2Furldefense.com*2Fv3*2F__https*3A*2F*2Fdatatracker.ietf.org*2Fdoc*2Fhtml*2Fdraft-ietf-sfc-multi-layer-oam*section-10.1__*3BIw!!MZ3Fw45to5uY!bzL7Vb_jHltGMCbCwne2rywfzpGjZW4o3fVr4clCr4Ir10KydDyJy5gHA8obfbMABJv1ohYIeg*24&data=04*7C01*7Cjames.n.guichard*40futurewei.com*7Ca5db82494c32402334fc08d9ebdc83cf*7C0fee8ff2a3b240189c753a1d5591fedc*7C1*7C0*7C637800154631277005*7CUnknown*7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0*3D*7C3000&sdata=HTLx6e4sQCvsjXZKxG1GA8XPvdswsQKEMIEABitkprw*3D&reserved=0__;JSUlJSUlJSUlJSUqJSUlJSUlJSUlJSUlJSUl!!MZ3Fw45to5uY!f5SSgs9VAH1xxjFWgJMfr5ZlZH93z6GJlXoOgCmY8AVbjdeh2YlaUz632nE-HqDItW-EwTZ2zw$>
> :
>
>
>
>          - An SFC NSH Context Header(s) contain an OAM processing
>
>          instructions or data.
>
>
>
>          - The "Next Protocol" field determines the type of the payload.
>
>
>
> The above text suggests to me that if the O-bit is set and the next
> protocol is not active SFC OAM then it is **required** that OAM data will
> be in the NSH context headers (which is not the case for iOAM) and the next
> protocol will indicate what follows the NSH header. While iOAM does follow
> the NSH header as indicated by the next protocol there is still an
> expectation that OAM is also carried in the NSH context headers. This seems
> to be in conflict with RFC 8300 AND RFC 8924.
>
>
>
> This of course is just my reading of the text and I would like to hear
> yours and other folks thoughts.
>
>
>
> Jim
>
>
>
> *From:* Shwetha Bhandari <[e-mail]>
> *Sent:* Monday, January 31, 2022 11:25 PM
> *To:* Greg Mirsky <[e-mail]>
> *Cc:* James Guichard <[e-mail]>;
> [e-mail]; [e-mail]; [e-mail]
> *Subject:* Re: [sfc] WGLC for
> https://datatracker.ietf.org/doc/draft-ietf-sfc-ioam-nsh/
> <https://urldefense.com/v3/__https:/nam11.safelinks.protection.outlook.com/?url=https*3A*2F*2Furldefense.com*2Fv3*2F__https*3A*2F*2Fdatatracker.ietf.org*2Fdoc*2Fdraft-ietf-sfc-ioam-nsh*2F__*3B!!MZ3Fw45to5uY!bzL7Vb_jHltGMCbCwne2rywfzpGjZW4o3fVr4clCr4Ir10KydDyJy5gHA8obfbMABJu3416GCQ*24&data=04*7C01*7Cjames.n.guichard*40futurewei.com*7Ca5db82494c32402334fc08d9ebdc83cf*7C0fee8ff2a3b240189c753a1d5591fedc*7C1*7C0*7C637800154631277005*7CUnknown*7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0*3D*7C3000&sdata=NKz8*2Fm*2Fh7WXjK0OP8NF4j5cQ*2FYgSrSMULRmDt*2FkX*2B10*3D&reserved=0__;JSUlJSUlJSUlJSUlJSUlJSUlJSUlJSUlJSUlJSUlJQ!!MZ3Fw45to5uY!f5SSgs9VAH1xxjFWgJMfr5ZlZH93z6GJlXoOgCmY8AVbjdeh2YlaUz632nE-HqDItW8EWrHtpA$>
>
>
>
> Hi Greg,
>
>
>
> Sorry for the late action on this.
> https://datatracker.ietf.org/doc/html/draft-ietf-sfc-ioam-nsh-07
> <https://urldefense.com/v3/__https:/nam11.safelinks.protection.outlook.com/?url=https*3A*2F*2Furldefense.com*2Fv3*2F__https*3A*2F*2Fnam11.safelinks.protection.outlook.com*2F*3Furl*3Dhttps*3A*2F*2Fdatatracker.ietf.org*2Fdoc*2Fhtml*2Fdraft-ietf-sfc-ioam-nsh-07*26data*3D04*7C01*7Cjames.n.guichard*40futurewei.com*7Caf9cde32be65486e459d08d9e53ac90c*7C0fee8ff2a3b240189c753a1d5591fedc*7C1*7C1*7C637792862928234181*7CUnknown*7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0*3D*7C3000*26sdata*3Dpl23JSzuzl5p2F8vooPyxVcUnWRdcWx*2F26MRFfJAIh4*3D*26reserved*3D0__*3BJSUlJSUlJSUlJSUlJSUlJSUlJSU!!MZ3Fw45to5uY!bzL7Vb_jHltGMCbCwne2rywfzpGjZW4o3fVr4clCr4Ir10KydDyJy5gHA8obfbMABJvEbkwM5w*24&data=04*7C01*7Cjames.n.guichard*40futurewei.com*7Ca5db82494c32402334fc08d9ebdc83cf*7C0fee8ff2a3b240189c753a1d5591fedc*7C1*7C0*7C637800154631277005*7CUnknown*7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0*3D*7C3000&sdata=dpoyXLu*2F9fGVSgLtewdI7wNfSPdrkhs7FtBdD3Aq7*2B0*3D&reserved=0__;JSUlJSUlJSUlJSUqKioqKiolJSoqKioqKioqKioqKiUlKiolJSUlJSUlJSUlJSUlJSUlJSUl!!MZ3Fw45to5uY!f5SSgs9VAH1xxjFWgJMfr5ZlZH93z6GJlXoOgCmY8AVbjdeh2YlaUz632nE-HqDItW9PuM1neA$>
> has been now posted with the edits per this discussion.
>
>
>
> Hi Jim,
>
>
>
> After Greg's review please let us know if the changes are good to progress
> the draft to the next step.
>
>
>
> Thanks,
>
> Shwetha
>
>
>
> On Wed, Oct 27, 2021 at 7:31 PM Greg Mirsky <[e-mail]> wrote:
>
> Hi Shwetha,
>
> thank you for the detailed response to my comments. Please feel free to
> share any updates you're considering for the next version. I'll be glad to
> work together on these.
>
> I have several follow-up notes in-lined below under the GIM>> tag.
>
>
>
> Regards,
>
> Greg
>
>
>
> On Tue, Oct 26, 2021 at 6:51 PM Shwetha Bhandari <
> [e-mail]> wrote:
>
> Hi Greg,
>
>
>
> Sorry for the very late reply. Please find responses to your comments
> inline @Shwetha:
>
>
>
>
>
>
>
> On Wed, Sep 8, 2021 at 3:30 AM Greg Mirsky <[e-mail]> wrote:
>
> Dear Authors and All,
>
> I've read the current version of the draft and have some comments I'd like
> to share with you. I much appreciate your thoughts on where this work
> should go considering developments in other IETF WGs. Please find my notes
> and questions below:
>
>    - It is stated in the Abstract that:
>
>    In-situ Operations, Administration, and Maintenance (IOAM) records
>    operational and telemetry information in the packet while the packet
>    traverses a path between two points in the network.
>
> But that is the case only for the pre-allocated and incremental trace
> option types. The Direct Export option
> <https://urldefense.com/v3/__https:/nam11.safelinks.protection.outlook.com/?url=https*3A*2F*2Furldefense.com*2Fv3*2F__https*3A*2F*2Fnam11.safelinks.protection.outlook.com*2F*3Furl*3Dhttps*3A*2F*2Furldefense.com*2Fv3*2F__https*3A*2F*2Fdatatracker.ietf.org*2Fdoc*2Fdraft-ietf-ippm-ioam-direct-export*2F__*3B!!MZ3Fw45to5uY!db6q3n8-5YqHkLtf3wyeBoUpO72v7UzeDtfPNhyePahNAYMo9eFdQxxBWM4C7Z0OJKE0jphubQ*24*26data*3D04*7C01*7Cjames.n.guichard*40futurewei.com*7Caf9cde32be65486e459d08d9e53ac90c*7C0fee8ff2a3b240189c753a1d5591fedc*7C1*7C1*7C637792862928234181*7CUnknown*7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0*3D*7C3000*26sdata*3Di7sTr0MtC5qfzx3twOKSpbW8LkQJzsAJBxF*2FZPLUwKc*3D*26reserved*3D0__*3BJSUlJSUlJSUlJSUlJSUlJSUlJSUlJSUlJSUl!!MZ3Fw45to5uY!bzL7Vb_jHltGMCbCwne2rywfzpGjZW4o3fVr4clCr4Ir10KydDyJy5gHA8obfbMABJt0mRguJg*24&data=04*7C01*7Cjames.n.guichard*40futurewei.com*7Ca5db82494c32402334fc08d9ebdc83cf*7C0fee8ff2a3b240189c753a1d5591fedc*7C1*7C0*7C637800154631277005*7CUnknown*7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0*3D*7C3000&sdata=yVGpJY1y6dud5c44HOsptPjqEuXdNUa1DMzjAelvU5c*3D&reserved=0__;JSUlJSUlJSUlJSUqKioqKioqKioqKioqJSUqKioqKioqKioqKiolJSoqJSUlJSUlJSUlJSUlJSUlJSU!!MZ3Fw45to5uY!f5SSgs9VAH1xxjFWgJMfr5ZlZH93z6GJlXoOgCmY8AVbjdeh2YlaUz632nE-HqDItW-BwxdRIg$>
> does not write telemetry data into the data packet itself but export
> telemetry information in a specially constructed packet.
>
> And as we are talking about different IOAM trace options, the question of
> the scope of this document seems appropriate. There is a WGLC on two IOAM
> documents
> <https://urldefense.com/v3/__https:/nam11.safelinks.protection.outlook.com/?url=https*3A*2F*2Furldefense.com*2Fv3*2F__https*3A*2F*2Fnam11.safelinks.protection.outlook.com*2F*3Furl*3Dhttps*3A*2F*2Furldefense.com*2Fv3*2F__https*3A*2F*2Fmailarchive.ietf.org*2Farch*2Fmsg*2Fippm*2FA0OcGQ5LlNjnjfRVp_iUTMYMrcs*2F__*3B!!MZ3Fw45to5uY!db6q3n8-5YqHkLtf3wyeBoUpO72v7UzeDtfPNhyePahNAYMo9eFdQxxBWM4C7Z0OJKHOndSFRg*24*26data*3D04*7C01*7Cjames.n.guichard*40futurewei.com*7Caf9cde32be65486e459d08d9e53ac90c*7C0fee8ff2a3b240189c753a1d5591fedc*7C1*7C1*7C637792862928234181*7CUnknown*7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0*3D*7C3000*26sdata*3DcHtvsgDl*2FuzSv70oS9LN5l2o5nEIwiKHDZ1sfiFJCrE*3D*26reserved*3D0__*3BJSUlJSUlJSUlJSUlJSUlJSUlJSUlJSUlJSUlJSU!!MZ3Fw45to5uY!bzL7Vb_jHltGMCbCwne2rywfzpGjZW4o3fVr4clCr4Ir10KydDyJy5gHA8obfbMABJu2SsX7cg*24&data=04*7C01*7Cjames.n.guichard*40futurewei.com*7Ca5db82494c32402334fc08d9ebdc83cf*7C0fee8ff2a3b240189c753a1d5591fedc*7C1*7C0*7C637800154631277005*7CUnknown*7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0*3D*7C3000&sdata=Y*2BwywuTSj4SpugrjmDTquAY0MZWKoT43CMjsyha*2FnOc*3D&reserved=0__;JSUlJSUlJSUlJSUqKioqKioqKioqKioqKiolJSoqKioqKioqKioqKiUlKiolJSUlJSUlJSUlJSUlJSUlJSUl!!MZ3Fw45to5uY!f5SSgs9VAH1xxjFWgJMfr5ZlZH93z6GJlXoOgCmY8AVbjdeh2YlaUz632nE-HqDItW-FRADPxg$>
> active through September 15th at the IPPM WG. I believe that it would be
> beneficial if we had a single document that describes the applicability of
> IOAM in all its functionality defined by documents in IPPM WG. Of course,
> that cannot be a moving target as that would not be helpful. But since the
> IPPM WG discusses the progress of two IOAM documents, it could be a great
> time to address the applicability of the Direct Export trace type
> <https://urldefense.com/v3/__https:/nam11.safelinks.protection.outlook.com/?url=https*3A*2F*2Furldefense.com*2Fv3*2F__https*3A*2F*2Fnam11.safelinks.protection.outlook.com*2F*3Furl*3Dhttps*3A*2F*2Furldefense.com*2Fv3*2F__https*3A*2F*2Fdatatracker.ietf.org*2Fdoc*2Fdraft-ietf-ippm-ioam-direct-export*2F__*3B!!MZ3Fw45to5uY!db6q3n8-5YqHkLtf3wyeBoUpO72v7UzeDtfPNhyePahNAYMo9eFdQxxBWM4C7Z0OJKE0jphubQ*24*26data*3D04*7C01*7Cjames.n.guichard*40futurewei.com*7Caf9cde32be65486e459d08d9e53ac90c*7C0fee8ff2a3b240189c753a1d5591fedc*7C1*7C1*7C637792862928234181*7CUnknown*7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0*3D*7C3000*26sdata*3Di7sTr0MtC5qfzx3twOKSpbW8LkQJzsAJBxF*2FZPLUwKc*3D*26reserved*3D0__*3BJSUlJSUlJSUlJSUlJSUlJSUlJSUlJSUlJSUl!!MZ3Fw45to5uY!bzL7Vb_jHltGMCbCwne2rywfzpGjZW4o3fVr4clCr4Ir10KydDyJy5gHA8obfbMABJt0mRguJg*24&data=04*7C01*7Cjames.n.guichard*40futurewei.com*7Ca5db82494c32402334fc08d9ebdc83cf*7C0fee8ff2a3b240189c753a1d5591fedc*7C1*7C0*7C637800154631277005*7CUnknown*7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0*3D*7C3000&sdata=yVGpJY1y6dud5c44HOsptPjqEuXdNUa1DMzjAelvU5c*3D&reserved=0__;JSUlJSUlJSUlJSUqKioqKioqKioqKioqJSUqKioqKioqKioqKiolJSoqJSUlJSUlJSUlJSUlJSUlJSU!!MZ3Fw45to5uY!f5SSgs9VAH1xxjFWgJMfr5ZlZH93z6GJlXoOgCmY8AVbjdeh2YlaUz632nE-HqDItW-BwxdRIg$>
> and Loopback and Active flags defined in draft-ietf-ippm-ioam-flags
> <https://urldefense.com/v3/__https:/nam11.safelinks.protection.outlook.com/?url=https*3A*2F*2Furldefense.com*2Fv3*2F__https*3A*2F*2Fnam11.safelinks.protection.outlook.com*2F*3Furl*3Dhttps*3A*2F*2Furldefense.com*2Fv3*2F__https*3A*2F*2Fdatatracker.ietf.org*2Fdoc*2Fdraft-ietf-ippm-ioam-flags*2F__*3B!!MZ3Fw45to5uY!db6q3n8-5YqHkLtf3wyeBoUpO72v7UzeDtfPNhyePahNAYMo9eFdQxxBWM4C7Z0OJKHO7lReVw*24*26data*3D04*7C01*7Cjames.n.guichard*40futurewei.com*7Caf9cde32be65486e459d08d9e53ac90c*7C0fee8ff2a3b240189c753a1d5591fedc*7C1*7C1*7C637792862928234181*7CUnknown*7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0*3D*7C3000*26sdata*3D1kqtcu3xjl1C7ytQ*2BoaKdiQN96rQt94e1S2ElC0nD3M*3D*26reserved*3D0__*3BJSUlJSUlJSUlJSUlJSUlJSUlJSUlJSUlJSUl!!MZ3Fw45to5uY!bzL7Vb_jHltGMCbCwne2rywfzpGjZW4o3fVr4clCr4Ir10KydDyJy5gHA8obfbMABJt8NqRRKg*24&data=04*7C01*7Cjames.n.guichard*40futurewei.com*7Ca5db82494c32402334fc08d9ebdc83cf*7C0fee8ff2a3b240189c753a1d5591fedc*7C1*7C0*7C637800154631277005*7CUnknown*7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0*3D*7C3000&sdata=zzcnXlewWKrtEDv4BmsNNk4pvDlMKNKvPzBZ2dZJm5k*3D&reserved=0__;JSUlJSUlJSUlJSUqKioqKioqKioqKioqJSUqKioqKioqKioqKiolJSoqJSUlJSUlJSUlJSUlJSUlJSU!!MZ3Fw45to5uY!f5SSgs9VAH1xxjFWgJMfr5ZlZH93z6GJlXoOgCmY8AVbjdeh2YlaUz632nE-HqDItW-gOuTqwg$>.
> It would be concerning to have more than one SFC document describing the
> applicability of the generic IOAM mechanisms
>
>
>
> Shwetha> This is a fair point. We will revise the  draft with text in the
> abstract and Section 3 IOAM-Type to be updated to include the usage of
> trace and DEX options.  The encapsulation of IOAM options within NSH itself
> in its current form already supports all the IOAM Option Type defined both
> from draft-ietf-ippm-ioam-data and draft-ietf-ippm-ioam-direct-export
> along with the flags supported within the options. Hence the
> IOAM-data-field definitions in the draft will remain unchanged.
>
> GIM>> I agree that the definitions of the IOAM data-fields are invariant
> in various data plane encapsulations. You likely follow the discussion of
> the IAOM Direct Export and IOAM flags on the IPPM WG list. I think that for
> SFC NSH, IOAM Direct Export could be as simple as "use the local policy".
> The applicability of the Loopback and Active flags seems to require
> detailed explanation by SFP actors.
>
>
>
>
>
>
>    - The location of the IOAM header in the SFC NSH-encapsulated packet
>    is defined in Section 3:
>
>    IOAM-Data-Fields are carried in NSH
>
>    using a next protocol header which follows the NSH MD context
>
>    headers.
>
> I've checked RFC 8300 but couldn't find it defines the Next Protocol
> header. Also, it appears that NSH Context headers are optional. Hence my
> question. Is the presence of an NSH Context header required when using
> IOAM? Could you clarify which mechanism is used to identify the payload of
> an SFC NSH-encapsulated packet as IOAM?
>
> Shwetha> We will reword it, it is not Next Protocol header but using IOAM
> as a Next Protocol as described in Section 4.1 and requested in IANA
> section. Following is the proposed text to align with the RFC 8300
> reference to context headers following base header and service path header:
>
> "The NSH is defined in [RFC8300].  IOAM-Data-Fields are carried in
> NSH using a next protocol to identify IOAM data fields that follows NSH
> context headers."
>
> GIM>> I think that RFC 8300 views data following Context Headers as NSH
> payload, not being "in NSH".
>
>
>    - If I understand the format of the IOAM header defined in Section 3
>    correctly, the header's length is limited by 1020 octets, while the
>    effective length containing IOAM options and data - 1016 octets. Is that
>    correct? What is the recommended technique of collecting IOAM data that
>    exceeds that limit?
>
> Shwetha > IOAM options inherently support specifying the size limits at
> the node that added the IOAM options. While operationalizing the solution
> the data types included and number of nodes expected to be adding the data
> should be selected. This is covered in deployment
> considerations draft-brockners-opsawg-ioam-deployment.
>
>
>    - In Section 4.1, I've found the text reflecting the history of the
>    discussion about how to carry the IOAM header using NSH encapsulation. As
>    the text has no normative value, I suggest moving it into an Appendix.
>
> Shwetha > Agreed, revised draft will have this section moved to Appendix.
>
> GIM>> Thank you.
>
>
>    - I find the rules of handling the O-bit in NSH listed in Section 4.2
>    inconsistent and confusing. The IOAM header is not part of NSH
>    encapsulation but is a part of the payload. But in one case, when user data
>    follows it, the O-bit must not be set as. If there's no user data after the
>    IOAM header, then the O-bit must be set. But from the perspective of NSH
>    encapsulation, it includes specially constructed data added for the sole
>    purpose of collecting OAM/telemetry information. Then, why, in one case,
>    the O-bit is cleared and in the other set if, in both cases, the
>    NSH-encapsulated packet is used to perform the OAM function?
>
> Shwetha > The reason for not setting the O-bit for packets that contains
> actual user data is because RFC 8300 has " SF/SFF/SFC Proxy/Classifier
> implementations that do not support
>
>       SFC OAM procedures SHOULD discard packets with O bit set". It will be undesirable to discard packets with O-bit set that carry user data as IOAM can be inserted insitu.
>
> For synthetic traffic created for OAM along with IOAM-data-fields in NSH following the NSH OAM function with 0-bit set is desirable.
>
>  GIM>> This is an interesting situation. I agree that there could be an
> SFC element not supporting "SFC OAM procedures" (not clear what these are).
> By the same token, would such SFC element support IOAM, be capable of
> processing IOAM without adverse impact to user data? I am not certain and
> it seems that it might be better to recommend that NSH packets with IOAM be
> dropped by an SFP element if it does not support "SFC OAM". What are your
> thoughts?
>
>
>
>
>
> Thanks,
>
> Shwetha
>
> I much appreciate your consideration of my comments and questions and
> looking forward to your feedback.
>
>
>
> Regards,
>
> Greg
>
>
>
> On Wed, Aug 18, 2021 at 5:32 AM James Guichard <
> [e-mail]> wrote:
>
> Dear WG:
>
>
>
> This email starts a 2 week Working Group Last Call for
> draft-ietf-sfc-ioam-nsh [1].
>
>
>
> Please read this document if you haven’t read the most recent version and
> send your comments to the SFC WG list no later than September 1st 2021.
>
>
>
> If you are raising a point which you expect will be specifically debated
> on the mailing list, consider using a specific email/thread for this point.
>
>
>
> Lastly, if you are an author or contributor please response to indicate
> whether you know of any undisclosed IPR related to this document.
>
>
>
> Thanks!
>
>
>
> Jim & Joel
>
>
>
> [1] https://datatracker.ietf.org/doc/draft-ietf-sfc-ioam-nsh/
> <https://urldefense.com/v3/__https:/nam11.safelinks.protection.outlook.com/?url=https*3A*2F*2Furldefense.com*2Fv3*2F__https*3A*2F*2Fnam11.safelinks.protection.outlook.com*2F*3Furl*3Dhttps*3A*2F*2Furldefense.com*2Fv3*2F__https*3A*2F*2Fdatatracker.ietf.org*2Fdoc*2Fdraft-ietf-sfc-ioam-nsh*2F__*3B!!MZ3Fw45to5uY!db6q3n8-5YqHkLtf3wyeBoUpO72v7UzeDtfPNhyePahNAYMo9eFdQxxBWM4C7Z0OJKHdTiRE6A*24*26data*3D04*7C01*7Cjames.n.guichard*40futurewei.com*7Caf9cde32be65486e459d08d9e53ac90c*7C0fee8ff2a3b240189c753a1d5591fedc*7C1*7C1*7C637792862928234181*7CUnknown*7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0*3D*7C3000*26sdata*3D9uDdhw0ViwBtWvn52V8UZ2G77lRnSye2Ols5z3U8QwQ*3D*26reserved*3D0__*3BJSUlJSUlJSUlJSUlJSUlJSUlJSUlJSUlJSU!!MZ3Fw45to5uY!bzL7Vb_jHltGMCbCwne2rywfzpGjZW4o3fVr4clCr4Ir10KydDyJy5gHA8obfbMABJv33kGkLw*24&data=04*7C01*7Cjames.n.guichard*40futurewei.com*7Ca5db82494c32402334fc08d9ebdc83cf*7C0fee8ff2a3b240189c753a1d5591fedc*7C1*7C0*7C637800154631277005*7CUnknown*7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0*3D*7C3000&sdata=S6sx7MrrVkzKepVgj45q*2F2KPZzBMyOFnol*2BMfgRQ730*3D&reserved=0__;JSUlJSUlJSUlJSUqKioqKioqKioqKioqJSUqKioqKioqKioqKiolJSolJSUlJSUlJSUlJSUlJSUlJSUl!!MZ3Fw45to5uY!f5SSgs9VAH1xxjFWgJMfr5ZlZH93z6GJlXoOgCmY8AVbjdeh2YlaUz632nE-HqDItW-FOmuSHA$>
>
>
>
>
>
>
>
> _______________________________________________
> sfc mailing list
> [e-mail]
>
> _________________________________________________________________________________________________________________________
>
> Ce message et ses pieces jointes peuvent contenir des informations confidentielles ou privilegiees et ne doivent donc
> pas etre diffuses, exploites ou copies sans autorisation. Si vous avez recu ce message par erreur, veuillez le signaler
> a l'expediteur et le detruire ainsi que les pieces jointes. Les messages electroniques etant susceptibles d'alteration,
> Orange decline toute responsabilite si ce message a ete altere, deforme ou falsifie. Merci.
>
> This message and its attachments may contain confidential or privileged information that may be protected by law;
> they should not be distributed, used or copied without authorisation.
> If you have received this email in error, please notify the sender and delete this message and its attachments.
> As emails may be altered, Orange is not liable for messages that have been modified, changed or falsified.
> Thank you.
>
>