SPRING @IETF-126

Wednesday 22 July 2026
Room: Grand Park Hall 1
9:00 - 11:00, Local
Log into the IETF datatracker to access:

SPRING WG Meeting Agenda

9:00 SPRING Status - Chairs (10 mins)

9:10 SRv6 for Redundancy Protection (10 mins)

Presenter: Bala'zs Varga
draft-ietf-spring-sr-redundancy-protection

no comments from the community

Bruno: When to have the next version?

Bala'zs: End of summer

Bruno: We will check the latest verion and may do another call.

9:20 Segment Routing Policy Extension for Network Resource Partition (10 mins)

Presenter: Shengnan Yue
draft-ietf-spring-sr-policy-nrp

Zafar Ali: Another CP level is an issue.

Jie Dong: In the draft we show that it is valid to have NRPID associated
with different CPs.

Zafar Ali: It is difficult for the hardware to switch NRPID on the fly.

Joel: Zafar, you ask for NRPID or NRP selector ID?

Zafar Ali: I ask from the hardware perspective.

Jie: Add as a policy-level attribute?

Zafar: Yes, more discussions offline.

Jie: We can discuss how to describe it in the architecture draft.

9:30 SRv6 Service Programming (10 mins)

Presenter: Ahmed Abdelsalam
draft-ietf-spring-srv6-service-programming

no comments from the community

Alvaro: Please pay attention to the draft since it will unlock the YANG
models. Please review.

9:40 SID as source address in SRv6 (10 mins)

Presenter: Feng Yang
draft-yang-spring-sid-as-source-address

Daniel Bernier: A few other usecases, such as optimizing Reverse Path
Forwarding (RPF) for Service Function Chaining (SFC) and return path
optimization, will contact offline.

9:50 Multipath Traffic Engineering for Segment Routing (10 mins)

Presenter: Andrew Stone
draft-stone-spring-mpte-sr

Bruno: Extensions to PCEP or BGP?

Andrew: At this moment no.

Chris Martin: how downstream path failures are communicated to the
headend.

Andrew: SBFD runs independently on downstream junction nodes and
cascades back. If all outgoing paths of a junction node fail, the node
stops processing the binding SID, triggering the upstream node's SBFD
session to fail.

Chris Martin: Align the SBFD behavior with ongoing work on BFD strict
mode additions.

Himanshu Shah: whether a centralized DAG computation is necessary when
nodes could compute paths locally using FlexAlgo and ECMP.

Andrew Stone: When routing off the shortest path to spread traffic, the
path explosion makes ingress-only representation unscaleable. A DAG
efficiently compresses these paths across intermediate junction nodes.

Sue Hares: Please sync, so we can feed into BGP.

Bruno: In terms of adoption, we will wait for the progress of the
architecture in the TEAS WG.

if time allows

10:00 ICMP Error Handling for VPNs in SRv6 Networks (10 mins)

Presenter: Balazs Varga / Zafar Ali
draft-varhal-6man-icmp-srv6-vpn

Bruno: We want to discuss requirements but too much details on the
solution.

Sasha Vainshtein: How a P-node would handle layer 2 VPN services.

Zafar Ali: When an exception occurs, the packet goes to the slow path,
which determines the appropriate forwarding action based on local policy
and packet content.

Joel: As a co-author, we need to get agreement on this merged approach,
after which the working group can determine which components fall under
SPRING versus 6man.

10:10 SRv6 BSID with Notification Message Relay (10 mins)

Presenter: Yao Liu
draft-liu-spring-srv6-bsid-relay

Joel: Slide 4, whether the headend receiving the relayed ICMPv6 packet
would be confused by receiving error messages for outer headers it did
not generate.

Zafar: The merged ICMP error handling proposal solves this without
requiring new relay states.

Yao Liu: It describes a generic P-node ping/trace behavior.

Daniel Bernier: Merge this work as a specific flavor or use case within
the SID source address draft to avoid creating separate independent
specifications.

10:20 SRv6 Path Verification (10 mins)

Presenter: Feng Yang
draft-yang-spring-srv6-verification

no comments from the community

10:30 SRv6 behavior extention for Flow Control in WAN (10 mins)

Presenter: Zhengxin Han
draft-ruan-spring-priority-flow-control-sid

no comments from the community

10:40 SRv6 for PPPoE Transport (10 mins)

Presenter: Cancan Huang
draft-song-spring-pppoe-srv6

Daniel Bernier: Whether using PPPoE over SRv6 is necessary when PPP over
SRv6 could be run directly. Suggested bringing the subscriber steering
requirements to the Broadband Forum (BBF).

Sasha Vainshtein: Slide 7. Typo or mistake? PPPoE is an EtherType inside
the Ethernet frame rather than an upper-layer header type in SRv6. PPPoE
has been successfully carried over MPLS pseudowires for two decades
without requiring special pseudowire types.

Joel: Talk about potential deployment. Please dont talk about revenue,
cost, and profit.