Minutes IETF97: spring
minutes-97-spring-01

SPRING WG - Source Packet Routing in Networking

        Thursday, November 17, 2016
        9:30-11:00  Thursday Morning session I
        Room:    Grand Ballroom 3
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WG Chairs status
Chairs, 15 min

http://recs.conf.meetecho.com/Playout/watch.jsp?recording=IETF97_SPRING&chapter=chapter_1&t=0

Serious issue in responsiveness of authors to IPR polls
Chairs stress the importance of authors' and wg's engagement with regards to
challenging objective which is being set: pack of 4 documents to IESG within 1
month, 2nd pack of 4 before next meeting.

Chris: any update on architecture document? What is expected in v10?
Stefano: under review between authors, integrates strict spf comments, should
be submitted next week. Chris: Does it include the SRLB additions to the IGP
drafts. Stefano: no, no impact on architecture. Chris: thanks for clarification

o Segment Routing Conflict Resolution
draft-ietf-spring-conflict-resolution-02
Les, 15 min

Presentation:
http://recs.conf.meetecho.com/Playout/watch.jsp?recording=IETF97_SPRING&chapter=chapter_1&t=622

currently draft has chosen the path of ignore overlap only. introduces
implementation complexity and potential interop issues. competing goals:
maximize traffic delivery Vs keep conflict resolution policy simple

Discussion:
http://recs.conf.meetecho.com/Playout/watch.jsp?recording=IETF97_SPRING&chapter=chapter_1&t=1640

[?]: if order not followed then interop issues?
Les: yes
[?]: but you don't control the receive order
Les: true but transient
[?]: keep it simple is important, for debugging also.

Shraddha: shouldn?t we also have a protocol preference? and that it be most
important. Les: this is explicitly stated in the draft. Forwarding plane is
agnostic to the protocol. Thus intentionally not included. Shraddha: if
conflicting entries between ISIS and OSPF, protocol preference should be used.
Shraddha: let's discuss on the list

George: if there is a conflict something is broken. whatever allows to find
what is broken is goodness

Robin: problem would not exist with global label. also vendors do not use SRGB.
This mainly a config issue, we should not spend that much time on this.

Jessy?: some other scenario of conflict exist (same prefix with same SID,
anycast SID) Les: covered in draft Jessy?: other scenario, different IGPs,
different domains, ... How to resolve the associated conflicts. Les: on
protocols, covered in the draft; On domain, we are not trying to resolve
conflicts across domains.

Robin: could have other issues with other protocols. policy will become even
more complex. we don't want that.

Wim: operators should speak-up.

Stefano: just want to emphasize what Wim just said.

John (Google): not interested in this solution Would like the simple one.

St?phane (Orange): yes, but errors can happen so we want to maximize traffic
delivery

Jeff: SR deployments exist. go talk to operators.

o YANG Data Model for Segment Routing
draft-ietf-spring-sr-yang-05
St?phane, 15 min
Presentation:
http://recs.conf.meetecho.com/Playout/watch.jsp?recording=IETF97_SPRING&chapter=chapter_1&t=2410

Discussion:
http://recs.conf.meetecho.com/Playout/watch.jsp?recording=IETF97_SPRING&chapter=chapter_1&t=2730

Robin: My ideas are not represented in this yang model
St?phane: document reflects the WG consensus. We need to focus on stable
elements. Could be enhanced in the future. Chair: I second that

o SPRING non protected paths
draft-litkowski-spring-non-protected-paths-00
St?phane, 15 min

Presentation:
http://recs.conf.meetecho.com/Playout/watch.jsp?recording=IETF97_SPRING&chapter=chapter_1&t=2914

Discussion:
http://recs.conf.meetecho.com/Playout/watch.jsp?recording=IETF97_SPRING&chapter=chapter_1&t=3354

Jeff: destination based forwarding isn't it?
Stephane: from service or transport PoV?
Jeff: transport
St?phane: a customer may indeed want a protected path, another a non-protected
path, ... Jeff: that an overload of semantics

Acee: 3 SIDs with different attributes. not an issue.

Jeff: not really different from FRR over optical restoration. Only need to make
sure that upper layer kicks-in before re optimization under layer St?phane:
yes, but we don't know the timers. Jeff: I mean scope is wide. It's a valid
problem worth working on.

Chris: with node-SID solution, it's going to converge with IGP. Is that a
problem? St?phane: regular convergence is acceptable. automatic is needed.

Acee: 2nd solution is best.
St?phane: which flavour?
Acee: with an additional flag on Node SID
Acee: worth working on

Jeff: with IGP reconvergence you might end up back on shortest path.

Shraddha: protection is not really important for customers.
St?phane: yes here. This is similar to optical transport service.
Shraddha: If you use Node-Sid it can change.
St?phane: True

Robin: what is application scenario?
St?phane: SR-TE
Robin: Which status are you targeting?
St?phane: Standard Track

o Segment Routing Recursive Information
draft-filsfils-spring-sr-recursing-info-03
Stefano, 15 min

Presentation:
http://recs.conf.meetecho.com/Playout/watch.jsp?recording=IETF97_SPRING&chapter=chapter_1&t=3900

Discussion:
http://recs.conf.meetecho.com/Playout/watch.jsp?recording=IETF97_SPRING&chapter=chapter_1&t=4200

Robin: we have proposed the same two years ago. Did you read my draft?
Stefano: no I did not read it
Robin: also I proposed this on the list.
Stefano: if that is the case and we are in agreement then we merge the drafts

Dave Allan: PHP could not be used, is that correct?
Stefano: no, you can still use PHP, you know the significance of that local
label.

Robin: I hope you will read the mailing list of the SPRING WG to remind your
memory Stefano: send to me your ideas and not assume I will dig into the
archives two to three years back

[?]: useful cases for that, but could be achieved with IS-IS SID and Labeled
BGP sessions between local node and target node, ... Stefano: this draft
follows a requirement expressed in IGP WGs, but I agree there are plenty other
ways to solve this [?]: some discussion on this would be useful