Hi Alia, I spoke to Peter and I think the OSPFv3 Bier Extensions should go into a separate OSPFv3 draft. Heretofore, all the work has been done in the BIER working group and it seems it would make sense to do it here rather than mix much into the overflow draft. As for the OSPF WG, the priority needs to be to publish the OSPFv3 Extended LSA draft. I’ll ask Abhay to start the WG last call and concurrently post the implementation information.
Thanks, Acee From: Alia Atlas <akat...@gmail.com<mailto:akat...@gmail.com>> Date: Monday, October 2, 2017 at 2:32 PM To: "Peter Psenak (ppsenak)" <ppse...@cisco.com<mailto:ppse...@cisco.com>>, Acee Lindem <a...@cisco.com<mailto:a...@cisco.com>> Cc: "b...@ietf.org<mailto:b...@ietf.org>" <b...@ietf.org<mailto:b...@ietf.org>>, OSPF WG List <ospf@ietf.org<mailto:ospf@ietf.org>>, "draft-ietf-bier-ospf-bier-extensi...@ietf.org<mailto:draft-ietf-bier-ospf-bier-extensi...@ietf.org>" <draft-ietf-bier-ospf-bier-extensi...@ietf.org<mailto:draft-ietf-bier-ospf-bier-extensi...@ietf.org>> Subject: Re: early AD review of draft-ietf-bier-ospf-bier-extensions-07 On Mon, Oct 2, 2017 at 2:26 PM, Peter Psenak <ppse...@cisco.com<mailto:ppse...@cisco.com>> wrote: Hi Alia, please see inline: On 02/10/17 17:33 , Alia Atlas wrote: On Mon, Oct 2, 2017 at 11:07 AM, Peter Psenak <ppse...@cisco.com<mailto:ppse...@cisco.com> <mailto:ppse...@cisco.com<mailto:ppse...@cisco.com>>> wrote: Hi Alia, please see inline: On 02/10/17 16:41 , Alia Atlas wrote: Hi Peter, On Mon, Oct 2, 2017 at 10:05 AM, Peter Psenak <ppse...@cisco.com<mailto:ppse...@cisco.com> <mailto:ppse...@cisco.com<mailto:ppse...@cisco.com>> <mailto:ppse...@cisco.com<mailto:ppse...@cisco.com> <mailto:ppse...@cisco.com<mailto:ppse...@cisco.com>>>> wrote: Hi Alia, please see inline: On 27/09/17 00:12 , Alia Atlas wrote: I have done an early AD review of draft-ietf-bier-ospf-bier-extensions-07 in preparation for the publication request. First, I would like to thank the many authors for their work on this draft. Given that there are currently 7 authors listed, I'd recommend appointing a few editors or otherwise reducing down to 5 or fewer. Of course, I am also willing to consider extraordinary circumstances where the shepherd can explain to me privately the deep technical contribution made by each author. I do see a number of major issues. Major Issues: 1) RFC7684 is just for OSPFv2. How is the information carried for OSPFv3? We need a mechanism that works for IPv6 also. BIER extension for OSPFv3 will be covered in a separate draft. It will be based on draft-ietf-ospf-ospfv3-lsa-extend draft. This is similar to what we did for SR and other extensions. I understand that theory - but I think it is getting less tractable. How far along is that draft? I'll need to at least reference it and discuss the IPv6 support in the write-up. Once draft-ietf-ospfv3-lsa-extend is published as an RFC, I would really expect this to stop happening. given that the encoding of the OSPFv3 is way different to OSPFv2 and the fact that the draft-ietf-ospfv3-lsa-extend is still a work in progress I would tend to keep the v2 and v3 extensions separate. Given the second, that's ok - but usually the difference in encoding isn't enough to require a different draft. Please do talk to Acee about this. He's collecting OSPFv3 LSA extensions to add to a separate draft when draft-ietf-osfpv3-lsa-extend progresses - and that draft is just waiting on the implementations (and there are finally 2 of them) so I expect it to move along soon. When you say "discuss the IPv6 support in the write-up" do you mean to mention it in draft-ietf-bier-ospf-bier-extensions? If yes, why? This documents only specifies OSPFv2 extension. No - I mean in the shepherd's write-up - though an informative reference to an OSPFv3 draft or a common one would help. At the moment, there's NOTHING about IPv6 and that's going to make it harder to get IESG agreement on. would stating in this document that OSPFv3 BIER extension will be covered in a separate draft help? It would need more than that. Let's see what Acee thinks is a reasonable approach. My tendency would be to reference the draft that is collecting OSPV3 Extended LSA TLVs - but I'm not sure if that draft is still merely conceptual. I don't know if you noticed that draft-ietf-sunset4-ipv6-ietf-01 ("IETF: End Work on IPv4") is in IETF Last Call. Of course, it has lots of caveats and is getting a number of concerned comments - but the trend is obvious as is the deployment of IPv6 and the need for feature parity. not that I disagree, but let's not get into that discussion here :) Just calling your attention to the current atmosphere :-) 2) In Sec 2.1, the Length is defined as variable and the figure includes additional sub-TLVs. Please clarify in the text what other sub-TLVs can be carried & how the length is calculated (yes, same as always - but clarity helps with interoperability). will change to "Variable, dependent on sub-TLVs" language as we did in SR draft. Sounds good - Variable, 4 + length of sub-TLVs I think. I.e., be clear on the length contributed by this TLV as well as the included sub-TLVs. not that I care too much, but I would like to keep the language same between documents. Unless you insist otherwise, keeping the "Variable, dependent on sub-TLVs" would make it consistent with other docs. Well, I don't deeply care either (beyond bike-shed painting) - but there is content to the TLV so it has length to be included in the calculation. 3) Sec 2.2 "The size of the label range is determined by the number of Set Identifiers (SI) (section 1 of [I-D.ietf-bier-architecture]) that are used in the network. Each SI maps to a single label in the label range. The first label is for SI=0, the second label is for SI=1, etc.: This implies that there is no way to indicate only a label for SI=1 or a range for SI=1 to 3. That seems unfortunate and assumes that the BFR-ids are always allocated from SI=0 up. Is there a reason not to use some of the reserved bits to indicate the starting SI value? I hope this has been clarified by Andrew and Tony already. Sure - I'm fine with what the WG wants here - and labels aren't too limited. My concern was about efficiency and future flexibility. 4) Sec 2.3: The Tree type is a 1 octet value - that doesn't appear to have any IANA allocation or meaning clearly indicated - beyond the parenthetical that 0=SPF. Please fix this. will add description for value 0. Will also add the need for new registry in "IANA Considerations" section. Cool - unless there's a reason, could it be a BIER-related registry that both the IS-IS work and OSPF work can refer to? right, that make sense. In such case, it should be defined outside of IGP BIER drafts, shouldn't it? It's ok to have it here. This is a BIER WG draft and it isn't needed until this or the ISIS one. Either can work. It could be in the mpls-encap draft, but that's ready for IETF Last Call and it isn't used there - so it would need more explanation. ok, I define it here. Sounds good. Thanks! Alia thanks, Peter 5) Sec 2.5: This section could benefit greatly from a diagram - showing the advertising router for a prefix, the ABR, and what is then flooded for the BIER MPLS Sub-TLV for the new areas. can you please clarify what type of diagram do you have in mind? A fairly simple one :-) where there are 3 areas - with the middle being the backbone. Have a BFER in each area. Describe what is advertised by each BFER and then by the ABR. I tend to agree with Andrew that we have similar section in many other documents and we've never included any diagram really. Anyway, I don't have a problem adding it if it helps. Frankly, the language/phrasing was such that I had to stop and think about it for 5 minutes or so to be confident that I understood and agreed with what was there. That's generally my sign that added clarity could be useful - but it could just be me or a bad day. let me try. Thanks, Alia thanks, Peter Minor: 4) Sec 2.3: "Label Range Base: A 3 octet field, where the 20 rightmost bits represent the first label in the label range." What about the top 4 bits? Are they Must Be Zero (MBZ)? How about making that explicit? Are they potential future flags?/ top for bits are ignored. I'll spell that out explicitly. Sounds good. I look forward to getting these from the WG. If I can put them into IETF Last Call by the end of the week, then we can have them on the Oct 26 telechat and hopefully approved before IETF 100. Regards, Alia thanks, Peter Thanks, Alia
_______________________________________________ OSPF mailing list OSPF@ietf.org https://www.ietf.org/mailman/listinfo/ospf