Re: [ippm] [sfc] WGLC for https://datatracker.ietf.org/doc/draft-ietf-sfc-ioam-nsh/
Greg Mirsky <gregimirsky@gmail.com> Tue, 12 April 2022 15:54 UTC
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From: Greg Mirsky <gregimirsky@gmail.com>
Date: Tue, 12 Apr 2022 08:53:56 -0700
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To: Shwetha Bhandari <shwetha.bhandari@thoughtspot.com>
Cc: Med Boucadair <mohamed.boucadair@orange.com>, "Frank Brockners (fbrockne)" <fbrockne=40cisco.com@dmarc.ietf.org>, "sfc-chairs@ietf.org" <sfc-chairs@ietf.org>, "sfc@ietf.org" <sfc@ietf.org>, "ippm@ietf.org" <ippm@ietf.org>, James Guichard <james.n.guichard@futurewei.com>, Tal Mizrahi <tal.mizrahi.phd@gmail.com>, "draft-ietf-sfc-ioam-nsh@ietf.org" <draft-ietf-sfc-ioam-nsh@ietf.org>
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Subject: Re: [ippm] [sfc] WGLC for https://datatracker.ietf.org/doc/draft-ietf-sfc-ioam-nsh/
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Hi Shwetha, I believe that the text you've quoted is helpful. I would suggest changing references from [RFC8300] to [I-D.ietf-sfc-oam-packet] throughout that paragraph. Regards, Greg On Tue, Apr 12, 2022 at 7:56 AM Shwetha Bhandari < shwetha.bhandari@thoughtspot.com> wrote: > 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 <mohamed.boucadair@orange.com> 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 <sfc-bounces@ietf.org> *De la part de* Frank Brockners >> (fbrockne) >> *Envoyé :* mardi 12 avril 2022 13:55 >> *À :* BOUCADAIR Mohamed INNOV/NET <mohamed.boucadair@orange.com>; >> Shwetha Bhandari <shwetha.bhandari@thoughtspot.com>; Greg Mirsky < >> gregimirsky@gmail.com> >> *Cc :* sfc-chairs@ietf.org; sfc@ietf.org; ippm@ietf.org; James Guichard < >> james.n.guichard@futurewei.com>; Tal Mizrahi <tal.mizrahi.phd@gmail.com>; >> draft-ietf-sfc-ioam-nsh@ietf.org >> *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:* mohamed.boucadair@orange.com <mohamed.boucadair@orange.com> >> *Sent:* Monday, 4 April 2022 07:40 >> *To:* Shwetha Bhandari <shwetha.bhandari@thoughtspot.com>; Greg Mirsky < >> gregimirsky@gmail.com> >> *Cc:* sfc-chairs@ietf.org; Frank Brockners (fbrockne) <fbrockne@cisco.com>; >> sfc@ietf.org; James Guichard <james.n.guichard@futurewei.com>; Tal >> Mizrahi <tal.mizrahi.phd@gmail.com>; draft-ietf-sfc-ioam-nsh@ietf.org >> *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$> >> ]. >> >> >> >> which means that “None” is authorized. The O-bit must be set for such >> packets, while it should be unset for other values indicating user payload >> as per draft-ietf-sfc-oam-packet. Absent a pointer to the OAM packet, an >> implementer will have to guess the behavior to follow. >> >> >> >> BTW, the text quoted above when combined with: >> >> >> >> IANA is requested to allocate protocol numbers for the following "NSH >> >> Next Protocol" related to IOAM: >> >> >> >> …means that IOAM data can be encapsulated in IOAM data. I don’t think you >> want such a behavior. No? >> >> >> >> One last comment: please update the security considerations with >> NSH-specific considerations. An approach is to simply refer to Section 5 of >> draft-ietf-sfc-oam-packet. >> >> >> >> Cheers, >> >> Med >> >> >> >> *De :* sfc <sfc-bounces@ietf.org> *De la part de* Shwetha Bhandari >> *Envoyé :* lundi 4 avril 2022 02:41 >> *À :* Greg Mirsky <gregimirsky@gmail.com> >> *Cc :* sfc-chairs@ietf.org; Frank Brockners (fbrockne) < >> fbrockne@cisco.com>; sfc@ietf.org; James Guichard < >> james.n.guichard@futurewei.com>; Tal Mizrahi <tal.mizrahi.phd@gmail.com>; >> draft-ietf-sfc-ioam-nsh@ietf.org >> *Objet :* Re: [sfc] WGLC for >> https://datatracker.ietf.org/doc/draft-ietf-sfc-ioam-nsh/ >> <https://urldefense.com/v3/__https://datatracker.ietf.org/doc/draft-ietf-sfc-ioam-nsh/__;!!MZ3Fw45to5uY!JpBZ4H2-MNm5lJDGjooVj_3Sq-aX7gdh5qeoNPyZ69CXOFRhgdYmSOyreClzKvZDgPAiwaGN2YTO2qUw70GqHI4QEKQpGnBw0LXBXQ$> >> >> >> >> 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 <gregimirsky@gmail.com> 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$> like >> the following: >> >> For the IOAM functionality is SFC NSH described in this document the O bit >> >> in NSH MUST be set clear according to [I-D.ietf-sfc-oam-packet]. >> >> >> >> Regards, >> >> Greg >> >> >> >> On Sun, Apr 3, 2022 at 1:06 AM Shwetha Bhandari < >> shwetha.bhandari@thoughtspot.com> wrote: >> >> Hi Jim, Greg, >> >> >> >> We have addressed the additional comments received in this discussion. >> Can you please take a look : >> >> https://www.ietf.org/rfcdiff?url2=draft-ietf-sfc-ioam-nsh-08.txt >> <https://urldefense.com/v3/__https:/www.ietf.org/rfcdiff?url2=draft-ietf-sfc-ioam-nsh-08.txt__;!!MZ3Fw45to5uY!JYVtUwScRxFf7rDoRMpiv7YwbRTcaHXzsGIxr9eVEi_p_xSQUWAjDvFy_UhGEQbl8530VaLM0Tj7k5Wzu6YfUSVd4KRpUCA$> >> >> >> >> Thanks, >> >> Shwetha >> >> >> >> On Thu, Feb 10, 2022 at 11:27 PM James Guichard < >> james.n.guichard@futurewei.com> 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 <shwetha.bhandari@thoughtspot.com> >> *Sent:* Wednesday, February 9, 2022 9:57 AM >> *To:* Greg Mirsky <gregimirsky@gmail.com> >> *Cc:* James Guichard <james.n.guichard@futurewei.com>; >> draft-ietf-sfc-ioam-nsh@ietf.org; sfc@ietf.org; sfc-chairs@ietf.org >> *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 <gregimirsky@gmail.com> 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 < >> shwetha.bhandari@thoughtspot.com> 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$> - >> there is nothing specific for NSH on how the flags are to be handled. The >> IOAM specific fields are to be handled as recommended by the respective >> IOAM drafts. Do you see any specific NSH considerations to be documented >> for IOAM fields? >> >> >> >> Thanks, >> >> Shwetha >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> On Tue, Feb 1, 2022 at 4:29 PM James Guichard < >> james.n.guichard@futurewei.com> wrote: >> >> Hi Shwetha & Greg, >> >> >> >> Thank you for the update. >> >> >> >> I still believe however that more work is necessary to reconcile how SFC >> OAM is supposed to work. RFC 8300 says: >> >> >> >> O bit: Setting this bit indicates an OAM packet (see [RFC6291 >> <https://urldefense.com/v3/__https:/nam11.safelinks.protection.outlook.com/?url=https*3A*2F*2Furldefense.com*2Fv3*2F__https*3A*2F*2Fdatatracker.ietf.org*2Fdoc*2Fhtml*2Frfc6291__*3B!!MZ3Fw45to5uY!bzL7Vb_jHltGMCbCwne2rywfzpGjZW4o3fVr4clCr4Ir10KydDyJy5gHA8obfbMABJs06rKUNw*24&data=04*7C01*7Cjames.n.guichard*40futurewei.com*7Ca5db82494c32402334fc08d9ebdc83cf*7C0fee8ff2a3b240189c753a1d5591fedc*7C1*7C0*7C637800154631277005*7CUnknown*7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0*3D*7C3000&sdata=4wRcNgj93har9TlylAfX*2BtbW24VCqfneSZd0rD9CRzs*3D&reserved=0__;JSUlJSUlJSUlJSUlJSUlJSUlJSUlJSUlJSUl!!MZ3Fw45to5uY!f5SSgs9VAH1xxjFWgJMfr5ZlZH93z6GJlXoOgCmY8AVbjdeh2YlaUz632nE-HqDItW8b5uw-Yg$> >> ]). >> >> 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 <shwetha.bhandari@thoughtspot.com> >> *Sent:* Monday, January 31, 2022 11:25 PM >> *To:* Greg Mirsky <gregimirsky@gmail.com> >> *Cc:* James Guichard <james.n.guichard@futurewei.com>; >> draft-ietf-sfc-ioam-nsh@ietf.org; sfc@ietf.org; sfc-chairs@ietf.org >> *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 <gregimirsky@gmail.com> >> 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 < >> shwetha.bhandari@thoughtspot.com> 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 <gregimirsky@gmail.com> 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 < >> james.n.guichard@futurewei.com> 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 >> sfc@ietf.org >> >> _________________________________________________________________________________________________________________________ >> >> 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. >> >>
- Re: [ippm] [sfc] WGLC for https://datatracker.iet… Frank Brockners (fbrockne)
- Re: [ippm] [sfc] WGLC for https://datatracker.iet… mohamed.boucadair
- Re: [ippm] [sfc] WGLC for https://datatracker.iet… Shwetha Bhandari
- Re: [ippm] [sfc] WGLC for https://datatracker.iet… mohamed.boucadair
- Re: [ippm] [sfc] WGLC for https://datatracker.iet… Greg Mirsky
- Re: [ippm] [sfc] WGLC for https://datatracker.iet… mohamed.boucadair
- Re: [ippm] [sfc] WGLC for https://datatracker.iet… Shwetha Bhandari
- Re: [ippm] [sfc] WGLC for https://datatracker.iet… Greg Mirsky
- Re: [ippm] [sfc] WGLC for https://datatracker.iet… mohamed.boucadair
- Re: [ippm] [sfc] WGLC for https://datatracker.iet… Frank Brockners (fbrockne)
- Re: [ippm] [sfc] WGLC for https://datatracker.iet… Frank Brockners (fbrockne)
- Re: [ippm] [sfc] WGLC for https://datatracker.iet… Shwetha Bhandari
- Re: [ippm] [sfc] WGLC for https://datatracker.iet… mohamed.boucadair
- Re: [ippm] [sfc] WGLC for https://datatracker.iet… xiao.min2
- Re: [ippm] [sfc] WGLC for https://datatracker.iet… Shwetha Bhandari
- Re: [ippm] [sfc] WGLC for https://datatracker.iet… Shwetha Bhandari
- Re: [ippm] [sfc] WGLC for https://datatracker.iet… mohamed.boucadair
- Re: [ippm] [sfc] WGLC for https://datatracker.iet… Greg Mirsky
- Re: [ippm] [sfc] WGLC for https://datatracker.iet… Shwetha Bhandari
- Re: [ippm] [sfc] WGLC for https://datatracker.iet… Joel Halpern
- Re: [ippm] [sfc] WGLC for https://datatracker.iet… Greg Mirsky
- Re: [ippm] [sfc] WGLC for https://datatracker.iet… Joel Halpern
- Re: [ippm] [sfc] WGLC for https://datatracker.iet… Joel Halpern
- Re: [ippm] [sfc] WGLC for https://datatracker.iet… Shwetha Bhandari
- Re: [ippm] [sfc] WGLC for https://datatracker.iet… Shwetha Bhandari
- Re: [ippm] [sfc] WGLC for https://datatracker.iet… Shwetha Bhandari
- Re: [ippm] [sfc] WGLC for https://datatracker.iet… Joel Halpern
- Re: [ippm] [sfc] WGLC for https://datatracker.iet… Shwetha Bhandari