* WGs marked with an * asterisk has had at least one new draft made available during the last 5 days

Spring Status Pages

Source Packet Routing in Networking (Active WG)
Rtg Area: Alvaro Retana, Deborah Brungard, Martin Vigoureux | 2013-Oct-25 —  

IETF-106 spring minutes

Session 2019-11-18 1000-1200: Padang - Audio stream - spring chatroom
Session 2019-11-21 1550-1720: Canning - Audio stream - spring chatroom


minutes-106-spring-02 minute

           SPRING WG - Source Packet Routing in Networking
                  Bruno Decraene
                  Rob Shakir
                  Shuping Peng
              Monday, November 18, 2019
              10:00 - 12:00, Monday Morning Session I
              Room: Padang
          o Administrivia
          [ 10 minutes ]
                  - Note Well
                  - Scribe
                  - Blue Sheets
                  - Document Status
          Comments on the slide - Beyond SRv6
              On the slides: The WG should continue to progress SRv6. Regarding the
              several solutions reducing the header size, the authors need to be
              explicit about the goals and the costs of their proposals in their
              document. Let's complete SRv6 work that we have and we engaged with
              6man, use the learnings there to try and guide some of these future
              decisions as to what the next steps after that should be.
              Kireeti Kompella: Is it the best approach for the IETF to complete
              SRv6 before really digging into these other proposals? Or is it better
              for us to look at all of them and see if maybe there is something
              there that either we come back to SRv6 and do it slightly differently
              or maybe even say that it is not completely the best approach.
              Rob Shakir: It is pretty clear across the comments on the mailing
              list that there are folks who are using this technology. So it is
              not unusable if we publish it.
              Kireeti Kompella: I was saying more like get a little further
              down the path of what's right and what's wrong about the current
              approach, and what are the things we want to fix? And if we then
              say the current approach is fine and then go ahead with that. But
              the idea that we complete this and use the learnings from this to
              inform the rest is fine but I think we could actually go a little
              further down the path of doing the analysis.
              Rob Shakir: I think absolutely we should continue to examining these
              other bits of work but we would like to do, the Chairs and the ADs of
              SPRING, is to allow that to happen not necessarily in the framework
              for them being working group drafts.
              Kireeti Kompella: Ok, all right thanks.
              Darren Dukes: Just to reiterate what you said. There are a lot of
              deployments. This stuff is deployed and this work is functional. It
              is implemented by multiple vendors. The standardization of it by
              this working group seems obvious at this point for SRv6.
              Andrew Alston:The last bullet point is creating a potential situation
              where some work is potentially hostage to other work.
              Rob Shakir: SRv6 is something that has been consensus of this working
              group to adopt. We have rough consensus for SRv6. There is rough
              consensus and running code, at this point I think it is difficult
              to argue though that we should not progress it. I don't think it is
              blocking other work. SR-MPLS progressed outside of having a working
              group and was adopted and had running code way before that time,
              and it did not stop that solution progressing.
              James Guichard: IETF works on certain principles and processes. One
              of those processes is that the working group will work based on
              the charter. The current SPRING charter says that the working group
              is there to work on SR-MPLS and SRv6. We should not be working on
              anything that is incompatible in the data plane with the existing
              solutions that we are working on. Some of the other solutions that
              are not compatible with SRv6. If other work wants to be done use
              the right IETF process, go and get your own working group, change
              the charter and do whatever you need to do.
              Darren Dukes: We have done that process for SR-MPLS and SRv6. We have
              architecture and a lot of maturity. If these other solutions want to
              progress, at the very least they need to define why they are better
              and why this working group should be interested in them. There is
              no justification for these other solutions.
              Rob Shakir: I think that is true for all proposals, not just true
              for alternative proposals, should be true for the amendments to the
              existing proposals. We should remember that the documents that we have
              adopted as working group are not individually owned any more.They are
              owned by the working group.Things go into the working group document
              should be by the consensus of working group not by the consensus of
              the authors of that work.
              Ron Shakir: Let's complete SRv6. But you have not mentioned is the
              degree to which other solutions are blocked. The other solution got
              flow time? Will they be able to ask for call for adoption?
              Rob Shakir: Flow time. If you look at the agenda over last n IETF
              the majority of our flow time is not all about the working group
              drafts. So absolutely we have been giving the individual drafts the
              time of the working group. If it is relevant to SPRING and specially
              there are discussions in the mailing list, it is fine to have flow
              time in this working group.
              Ron Bonica: Adoption call?
              Rob Shakir: That is the discussion that we will have to have. It isnt
              clear to me that we have got a good pattern that says that this is the
              level of benefits that one has to demonstrate to adopt different. We
              do have huge amount of competing solutions that we are looking to
              adopt. Maybe what we did like the NSH draft and service programming
              draft. We had technical discussions about what the two work solve,
              and we adopted both. I dont think adoption is blocked. But we do
              have to have the consensus of the group about the work.
              Ron Bonica:
              Andrew Alston: Fair enough Adoption call is not out of the question.
              Rob Shakir: The adoption will be based on the consensus of the
              working group. If charter update is required, then it is something
              that needs to be discussed with ADs.
          o SRv6 Network Programming
          [ 20 minutes ]
              Pablo Camarillo
              Pablo Camarillo: Ask for WG Last call
              Ron Shakir: In the terminology section, you mentioned that a single
              packet can carry two SRHs, is it one per IP header or two for the
              same IP header?
              Pablo Camarillo: In SRv6 network programming, we are not suggesting
              to craft a packet with two SRHs. But if we receive a packet with
              two SRHs, we must process according to RFC8200
              Ron Shakir: Can you add some text refer to RFC8200 saying that
              the packet should not carry two SRHs. But you will process it if
              it does.
              Pablo Camarillo: But the draft is not suggesting to craft a packet
              with two SRHs.
              Ron Bonica: Actually if you read the terminology section, it makes
              the suggestion.
              Pablo Camarillo: We can discuss in the mailing list.
              Greg Mirsky: If there are multiple SRHs, what would be the order
              of processing multiple headers? If segments left is zero in first
              header, what happens then?
              Darren Dukes: RFC8200 says to process them in the order received.
              Ron Bonica: Whether you can always skip over the routing header when
              the segment left equals to zero where you still need to look at the
              Type and Lengths in TLVs.
              Pablo Camarillo: The SRv6 network programming is defining how you
              process the SRH. Regarding the processing of other headers please
              refer to RFC 8200. It is not part of network programming.
              Ron Bonica: What you are saying is if segment left equals to zero,
              you may ignore all the flags and tags and TLVs.
              Pablo Camarillo: If segment left equals to zero then we dont process
              the SRH.
              Ron Bonica: OK, excellent.
              Darren Dukes: I think that we need text to describe that behavior,
              because I dont think it is necessarily the case. We need to add
              something there.
              Zafar Ali: Ron's comment is more applicable to OAM. OAM draft does
              explain that and was discussed in the mailing list. When a packet
              received with its segment left equals to zero, and if the O bit is
              set and the TLV will be processed.
              Ron Bonica: A bit of conflict. Needs to check RFC8200's requirement to
              skip over the routing header when the segment left equals to zero.
              Zafar Ali: Let's discuss it in the context of OAM draft. It does
              not affect the network programming draft.
              The authors think that it is ready for the WG Last Call.
          o YANG Data Model for SRv6 Base and Static
          [  5 minutes ]
              Sonal Agarwal
              Acee Lindem: We did that in the base for a lot of things we thought
              would need to be augmented. It forces to use identities. This will
              help in the future to add more functions with augmentation.
              Sonal Agarwal: Ask for WG adoption
                  Who read the draft?  about 15 persons
                  Who believe it's a good start for a WG document? about 15 persons
                  Who believe it's not a good start for a WG dcoument? nobody
          o YANG Data Model for Segment Routing Policy
          [ 10 minutes ]
              Kamran Raza
              Kamran Raza: Ask for WG adoption
              Shraddha Hegde: Config-Attributes tree. There is attribute section
              and affinity-map. Is it that you are modeling this SR policy as a
              link? Is it why there is this affinity-map here?
              Kamran Raza: The affinity map is for some of the dynamic constraint
              that you want to add to the policy. This could be leveraged from
              existing TE modelling. We are looking forward to see that how we
              can align with the color.
              Shraddha Hegde: The constraints for the dynamic policy?
              Kamran Raza: It is about constraints.
                  Who has read the draft?  about 15 persons
                  Who believe it's a good start for a WG document? about 15 persons
                  Who believe it's not a good start for a WG dcoument? nobody
          Unified Identifier in SRv6: use case and the solution
          [ 10 minutes ]
          o Unified Identifier usecase in IPv6 Segment Routing Networks
          o Unified Identifier in IPv6 Segment Routing Networks
              Weiqiang Cheng
              Ketan Talaulikar: The proposal is to put a lot of different mappings
              into the SRH which was meant for SRv6 SID. We have developed solutions
              in SPRING and MPLS WG for IPv6 using mappings and labels. SRv6 and
              SR-MPLS interworking draft is also related, we are looking for inputs
              on it.
              Greg Mirsky: True, there is a proposal to do SR-MPLS over IP. The
              important benefit of SRH is that preserves the path information
              from the source to the destination. SR-MPLS does not do that. The
              differentiator of the unified SID proposal is to use SRH to preserve
              the path information of a SR-MPLS path, which is a benefit. Using SRH
              gives the benefit of path information being available to the egress.
              Ketan: SRH is designed to carry SRv6 SID. Just using the header for
              carrying something different it is not really the same SRH. We have
              the interworking solution already, and should look at it.
              Greg Mirsky: Surprised that SRH can only carry specific size of
              SID. Let's discuss on the list.
              Ketan Talaulikar: To clarify, I was saying that SRH carries the SRv6
              SID. I didnot talk about the size of the SID.
              Kireeti Kompella: In the draft, you say that this is a way to
              upgrade from SRv6 to SR-MPLS. It is like going in the opposite
              direction. There are more SR-MPLS deployments than there are
              SRv6. It is useful to talk about that particular option. There are
              two bits. Are you also going to interoperate with SRm6?
              Weiqiang Cheng: Free reserved bits are used. We just gave some
              examples. I dont think it breaks the SRv6 rules.
              Greg Mirsky: It is good to emphasize that SR-MPLS and SRv6 are
              primary scenarios. In terms of the two-bit flag, we need to be
              compatible with the IPv6 SIDs, so 00 is given. Two others are open
              for discusions. Suggestions are welcomed.
              Darren Dukes: SR architecture is already RFC. SR-MPLS and SRv6
              interworking draft. We have couple of compression mechanisms that
              work without mapping table. We have 18 implementations from different
              vendors and merchant silicon vendors are implementing SRv6 without a
              mapping table. There is no description of what this work (and also
              SRm6) brings to the working group or the community in large over
              what has been already defined in RFCs. What are the benefits?
              Weiqiang Cheng: In the current POC, only the lookingup table. We
              could develop more smart way to optimise that.
              Darren Dukes: A new document for describing the processing in details
              and comparison and justification of why this work is needed?
              Weiqiang Cheng: Yes, the document will be built, and welcome
              Kamran Raza: Question about performance impact because of 2 lookup
              Greg Mirsky: No additonal impact comparing with SR-MPLS over IP.
              Robin Li: Requirement is important. Statics information is good to
              have from CMCC on the size of the SID and its distribution. Once the
              requirement is clear then we can work on the solutions and analyze
              the cost accordingly.
              Weiqiang Cheng: Ongoing work to deploy 35k nodes to support 5G
              backhaul in Bejing and have detailed calculation of required number
              of SIDs. Need to support more than 10 SIDs. Because of SRH overhead
              there is only 60% of capacity. We have optimise it otherwise we can
              not have large scale deployment. Future, we will have more detailed
              analysis in the control plane and management plane.
              David Melman: Compared with micro-SID solution?
              Greg Mirsky: Activities for the future work.
              Cheng Li: There is also another work on SRv6 compression. It would
              be good to make this kind of comparison.
              Ron Bonica: For the Beijing network if you tried the micro SID
              solution, you would need /32 so it is not a reliable solution.
              Bruno Decraene: It is the topic belongs to "Beyond SRv6". First we
              need to agree with what the goals are. Then we need to discuss the
              benefits and costs of each solution. We would like to converge the
              solutions in SPRING first. So far it is within SPRING.
              Greg Mirsky: Where is this work to continue? Suggestion from Chair.
              Bruno Decraene: So far it is up to the authors.
          o Segment Routing Mapped To IPv6 (SRm6)
          [ 10 minutes ]
              Reji on behalf of Ron Bonica
              Darren Dukes: You have not changed the title of the draft yet. It
              caused confusions.
              Reji Thomas: will update it.
              Darren Dukes: We dont see any justification for this work to be
              involved in SPRING. It is not in the current Charter.
              Reji Thomas: There are customers who are interested in SRm6.
              Andrew Alston: Justification has been pointed out in the mailing
              Darren Dukes: SRv6 has architecture and control plane work, and
              deployments. Now you are suggesting the working group to work on
              something else. But there is no justification. Onus is on the authors
              of this draft.
              Andrew Alston: Both work should exist and progress. Should let the
              operators to choose. SRH is in 6man. The micro SID draft actually
              acknowledged that there is the overhead problem.
              Martin Vigoureux: SRH is in the RFC editor queue, not in 6man
              Darren Dukes: A lot of background work built for SRv6. There is not
              the same background in the working group for SRm6 and SRv6.
              Andrew Alston: Not sure what is wanted from the SRm6
              Ketan Talaulikar: We already have work done on this topic. Why this
              cannot be achieved with what we have done with SR-MPLS?
              Andrew Alston: There is a demand in the market to move away from MPLS
              labels at the top of the packet. No desire to slow down ongoing SRv6
              Ketan Talaulikar: The mechanisms needed have already been done,
              why again?
              Andrew Alston: Operators want a choice. We believe that all
              alternatives should proceed.
              Ron Bonica: The difference of SRm6 is stated at the end of the
              draft. We can call out the motivations in the next revision.
              Darren Dukes: Content in section 9 is resolved with SRv6 in the
              current form. Needs more arugments in the draft to discuss.
              Zafar Ali: SRm6 requires new control plane and new data plane and
              new architecture. Then what about the past many years on SRv6?
              James Guichard: SRm6 is not compatible with SRv6,and it is not in
              the current SPRING Charter.
              Ron Bonica: Nobody is departing a new dataplane.
              Andrew Alston: SRm6 is on the v6 data plane.  Not an incompatible
              data plane.
              James Guichard: That can also be done with SRv6 as well. Two
              completely incompatible solutions are not desired.
              Ron Bonica: In order to really be compliant with the charter we need
              to comply both with RFC8200.
              John Scudder: Disappointing this debate is still going on.
              Robin Li: Requirements must be cleared, and the two types of
              requirements need to be distinguished: 1) to reduce the SRv6 SID size
              2) to propose new IPv6 based SR solutions. It is not reasonable to
              produce a new IPv6 based SR solution just for reducing the SRv6 SID
              size. It is a process issue, AD's email already asked to refocus to
              SRv6. SRm6 work should follow the IETF process, starting with the
              Problem statement and then the following process.
              Pablo Camarillo: This draft is not defining segment routing as
              defined in RFC8402. Why call it segment routing?
              Rob Shakir: Renaming it to something different won't change the
              problem space.
              Xing Li: China Education and Research Network (CERNET2) is the largest
              IPv6 only network and been running SRv6. We found that shorter SID
              has some benefits. We support both proposals. We should open our
              eyes for the new work.
              Kamran Raza: How many are on ASIC based implementation, and how many
              of those options at the line rate you can process?
              Reji Thomas: A VPN level part can be processed on a line rate.
              Cheng Li: Think about the cost of processing DOH TLV when you are
              talking about reducing the overhead of SRH. Overhead and processing
              cost should be considered.
              Andrew Alston: Ask for adoption of the SRm6 overview draft.
              Bruno Decraene: Need to ensure we understand the problem as we're
              hearing different things, also from the draft authors.
              Rob Shakir: Same comments will be raised if we do a call for adoption
              so we need to address those before that.
          o Path Segment for SRv6 (Segment Routing in IPv6)                        [
          7 minutes ]
              Cheng Li
              Cheng Li: ask for WG Adoption
              Weiqiang Cheng: Solution is important, especially for the large
              network operation.
          o Segment Routing Header encapsulation for In-situ OAM Data
          [ 10 minutes ]
              Zafar Ali
          o An Experiment of SRv6 Service Chaining at Interop Tokyo 2019 ShowNet
          [  5 minutes ]
              Ryo Nakamura
          The session is cut off from here.
          o SRv6 Tagging proxy
          [ 10 minutes ]
              Yukito Ueno
          o SRv6 for Deterministic Networking (DetNet)
          [ 10 minutes ]
          o DetNet SRv6 Data Plane Encapsulation
              Xuesong Geng
          Total Presentation Time:            107 minutes
          Speaker Shuffling Time/Buffer:      12 minutes
              Thursday, November 21, 2019
              15:50-17:20, Thursday Afternoon session II
              Room: Canning
          o Administrivia
          [  5 minutes ]
                  - Note Well
                  - Scribe
                  - Blue Sheets
                  - Document Status
              o SR Replication Segment for Multi-point Service Delivery
              [ 10 minutes ]
              Zafar Ali
              Zafar: The authors ask for WG adoption.
              Wim: It is a good idea. It is a easy way to support multicast.
              Himanshu£º Support the draft. Good ingress replication, pretty
              o BGP-LS Extensions for Inter-As TE using EPE based mechanisms
              [  5 minutes ]
              Shraddha Hegde
              Acee Lindem: F stands for FRR, right?
              Shraddha Hegde: Yes.
              Aijun Wang: Doesnt need every ASBR to run the protocol.
              Shraddha Hegde: Yes.
              Aijun Wang: In our network, the nodes are actually connected to ASBR,
              there maybe some extensibility issue.
              Shraddha Hegde: This mechanism is only for Inter-area path.
          o Performance Measurement Using TWAMP Light for Segment Routing Networks
          [ 10 minutes ]
              Bruno Decraene: how many have read the draft? - 10-15 persons
              Bruno Decraene: How many agree to adopt the draft? About the same
              Bruno Decraene: To further confirm in the list.
          o Segment Routing Generic TLV for MPLS Label Switched Path (LSP)
          Ping/Traceroute        [ 10 minutes ]
              Nagendra / Zafar
              Sam Aldrin: If anycast, what is the procedure to use to validate?
              Ketan Talaulikar: As long as it reached the anycast node, it is all
              good. Discuss offline.
              Sam Aldrin: How many other types of SID have been defined? Are you
              going to repeat the definition?
              Zafar Ali: If not covered yet, we will continue. Good to have an
              option for new definition. Asking for more feedback.
              Shraddha Hegde: Agree with Sam. We may find more corner cases.
              Zafar Ali: Please check the slides on Monday.
              Tarek Saad: Valid the assigner, what the SID is assigned to is
              missing. Just to valid the label is reasonable. Dont think you can
              deprecated the other effects that are defined.
              Zafar Ali: Agree.
              Jabber question from Srihari Ramachandra: if the link between 7 and
              8 becomes unidirectional, would you be able to define it?
              Zafar Ali: Yes.
              Greg Mirsky: It is also open to others.
              Zafar Ali: Let's keep the option open. It is SR focused.
          o Segment-Routing over Forwarding Adjacency Links
          [ 10 minutes ]
              Tarek Saad
              Dhruv Dhody: Would you compare this to binding SID?
              Tarek Saad: It can be a BSID. It can multiple LSPs.
              Dhruv Dhody: What is the benefit offering?
              Tarek Saad: There is no standard way how you push it into the TED.
              Dhruv Dhody: When would this link go down?
              Peter Psenak: What is the difference from regular SR TE Policy?
              Tarek Saad: FA link can be supported by one SR policy or multiple
              SR policies.
              Peter Psenak: So this is not traditional fowarding adjacency as we
              know it from RSVP-TE?
              Tarek Saad: FA link is a traffic engineering link. Please refer to
              the RFC I listed in the slides.
              Peter Psenak: As long as you dont advertise this as a link in the
              IGP topology it is fine.
              Ketan Talaulikar: Please refer to the draft we have for exporting
              such link via BGP-LS. The difference is not done as a link NLRI but
              as a TE Policy NLRI.
              Tarek Saad: Draft is gone through. Here it is just a link.
              Ketan Talaulikar: Just want to see if you want to add those on the
              SR policy.
              Tarek Saad: Sure, let's talk about it.
              Robin Li: Only SR-MPLS or both SR-MPLS and SRv6?
              Tarek Saad: Both.
              Jeff Tantsura: Please refer to a draft published on integration of
              IP and optical.
              Tarek Saad: ok.
          o Segment Routing for Enhanced VPN Service
          [ 10 minutes ]
              Jie Dong
              WG adoption has been requested.
              Bruno Decraene: The work in TEAS is generic.
              Bruno Decraene: who read the draft and who support? about the same
              Bruno Decraene: who think it is not ready? about 1-2 person. Now
              there is a design team on network slicing. We need to wait a bit
              for the outcome of the design team.
              Jie Done: The work can be decoupled. VPN+ framework is already adopted
              in TEAS. This is a solution for VPN+ and network slicing is one of
              its use cases. No need to rely on the work of design team in TEAS.
              Bruno Decraene: The name of the draft is a bit of marketing,
              could be useful to focus on what is added, such as network resource
              partitioning, and needs to fix the introduction. Terminologies need
              to be clarified.
              Jeff Tantsura: The design team's focus is not about the technology
              as such but the northbound API. Not going to work on this
              specifically. Please use the same term of
              Jie Dong: Sure.
              Fengwei Qin: The draft is a good idea and reflect the use cases.
              Ran Chen: Agree with Jeff. Out of scope of the design team. Another
              proposal will be presented later.
              Jie Dong: This is only on data plane. Control plane extensions are
              in other drafts.
              Bruno Decraene: Please send comments to the mailing list.
              Rakesh Gandhi: Requirement and framework are in the scope of the
              design team. We need to make progress in requirements and framework.
              Greg Mirsky: Encourage to work on the model that includes both
              resource sharing and isolation cases.
              Jie Dong: The two cases are already covered and we have clarified
              in the draft.
              Greg Mirsky: There are other resources.
              Jie Dong: We can discuss more.
              Bruno Decraene: Need to discuss on the list. You need to refine the
              draft to make the abstract and introduction inline with the scope,
              maybe rephrase as partitioning of network resources.
          o Building blocks for Slicing in Segment Routing Network
          [  8 minutes ]
              Zafar Ali
              Bruno Decraene: The first page is a good summary of all the tools
              we have in SPRING. What tools are missing in SPRING to fullfil the
              requirements for network slicing? One part could be a segregation
              of resources within the network.
              Jeff Tantsura: Use terminology correctly. It is not network slicing.
              Bruno Decraene/Zafar Ali: Please send comments on the list.
              Zhenqiang Li: Please add resource segment presented by Jie to the
              building blocks.
          o Packet Network Slicing using Segment Routing
          [ 10 minutes ]
              Fengwei Qin
              Bruno Decraene: Please mainly talk about the difference since we
              know the concept.
              Bruno Decraene: Since we don't have enough time, we dont have time
              for the details. We will refer to the TEAS design team's outcome.
          The session is cut off from here.
          o The Use of Path Segment in SR Inter-domain Scenarios
          [  5 minutes ]
              Quan Xiong
          Total Presentation Time:            83 minutes
          Speaker Shuffling Time/Buffer:      7 minutes

Generated from PyHt script /wg/spring/minutes.pyht Latest update: 24 Oct 2012 16:51 GMT -