IETF 126 MPLS WG Meeting (version 01)
Date/Time: Tuesday Session I, July 21, 2026 9:00 - 10:30 (local)
Room: Grand Klimt Hall 2
Slides:
https://datatracker.ietf.org/meeting/126/session/mpls/
Codimd for Notes Taking:
https://codimd.ietf.org/notes-ietf-126-mpls/
Meetecho:
http://www.meetecho.com/ietf126/mpls/
Zulip:
https://zulip.ietf.org/#narrow/stream/126-mpls
WG Status Update (Agenda Bashing) - 9:00
Duration: 10 mins
Presenter: WG Chairs
Tarek presents the chairs status update to the WG.
MNA Flag for MPLS On-path Telemetry - 9:10
ID:
https://datatracker.ietf.org/doc/draft-ietf-mpls-on-path-telemetry-flag
Duration: 10 mins
Presenter: Haoyu Song
^
Signaling MNA Capabilities Using LSP Ping - 9:20
ID:
https://datatracker.ietf.org/doc/draft-ihlesong-mpls-mna-signaling
Duration: 10 mins
Presenter: Fabian Ihle
[Zafar]: same comment from LSR. OAM and ping is not the right tool
for capability discovery. Also, change of capability is missed (not
notified). People have tried this approach in the past, but
discovered this is not the right approach.
Greg: following on Zafar's note. Why
not use YANG model and let the node advertise the capability.
[Fabian]: this is possible, but alternate approach.
Greg: using LSP ping has problem in
ECMP environment. Collected/discovered path is not always congruent
to the data flow path.
[Fabian]: yes. This needs to be looked at.
MPLS Network Action for Deterministic Networking - 9:30
ID: https://datatracker.ietf.org/doc/draft-ietf-mpls-mna-detnet
Duration: 10 mins
Presenter: Xueyan Song
No questions.
Operations, Administration and Maintenance (OAM) for Network
Resource Partition (NRP) in MPLS Network - 9:40
ID: https://datatracker.ietf.org/doc/draft-gong-mpls-nrp-oam-mpls
Duration: 10 mins
Presenter: Liyan Gong
[GregM]: the proposal is based on assumption if NRP is not
configured in dataplane, the OAM packet will be punted to control
plane.
[Liyan]: yes, this will follow the same approach as existing OAM
packets.
[GregM]: but if NRP is not configured, the packet may get dropped.
[GregM]: it seems the proposal is based on assumption that
dataplane will differeniate between DP and CP packet.
[Liyan]: no.
[GregM]: if NRP is encoded in DP on datapath, and packet has no
NRP selector then packet has to be dropped - do you agree?
[Liyan]: we need to agree, is punt should happen before action
drop.
[GregM]: maybe you need to define a new equivalence class for NRP
and then it can be used.
[ZafarA]: NRP is parallel to DSCP/EXP that has been in deployment
for years. It is getting complicated. Why can't we do the same
mechanisms known today for DSCP/EXP?
[Liyan]: there's a gap that we're trying to fill.
Explicit Congestion Notification Using MPLS Network Actions - 9:50
ID: https://datatracker.ietf.org/doc/draft-halmir-mpls-ecn
Duration: 10 mins
Presenter: Joel Halpern
[Adrian]: can you clarify what is this ECN notifying who?
[Joel]: a transit node that detects congestion will fill the
opcode and send it to the egress.
[Xueyen]: RFC5129 defines how to map DSCP to ECN. I think the work
is useful and necessary. You proposing 2 opcode (ISD/PSD) - why?
[Joel]: we did not want to hardcode that it had to be the same
opcode.
[GregM]: IANA provided feedback about the registry and we'll
reflect that it is same opcode to be used for both ISD/PSD.
[Adrian]: polled the room for people who read - not many.
Encourage more reviewers from the WG.
Supporting In Situ Operations, Administration, and Maintenance Using
MPLS Network Actions - 10:00
ID: https://datatracker.ietf.org/doc/draft-ietf-mpls-mna-ioam
Duration: 10 mins
Presenter: Rakesh Gandhi
[Adrian]: appreciate you taking it to IPPM. I usually would like
the WG has read and commented on the doc before adoption.
Signaling RSVP-TE Tunnels on an SR-MPLS Forwarding Plane Using
Adjacency Segment Identifiers - 10:10
ID:
https://datatracker.ietf.org/doc/draft-beeram-spring-rsvp-sr-mpls
Duration: 10 mins
Presenter: Vishnu Pavan Beeram
[Pavan]: request WG adoption and welcome feedback.
[Sasha]: would the ingress impose ADJ-SIDs for the path? Can it
push protected ADJ-SIDs?
[Pavan]: RFCxx talks about the use of protected/unprotected
ADJ-SIDs.
[Sasha]: I think you should avoid the case of protected ADJ-SiDs
and when facility bypass is used.
[Pavan]: existing FRR flags will tell what transit node is
protect/unprotect. There is a section in the doc.
[Zafar]: SR removes state from network. IGP installs/advertises
those SIDs. There's no need to signal/RSVP. This is against the SR
architecture.
[Pavan]: this is for scenarios that you want used distributed BW
management with SR Adj-SIDs.
[Zafar]: there are ways to do BW manangement for SR. You are
adding state in the network. One can run RSVP classic and not re-use
SR ADJ-SIDs.
[Pavan]: there are cases where we want to resuse the forwarding
plane
[Himanshu]: EXP bits are set for all labels or just the top.
[Pavan]: This is orthogonal and will follow the usual procedures
for any MPLS label stack.
Signaling Optimization Objective and Bounded Metrics for MPLS Fast
Reroute Backup LSP Tunnels - 10:20
ID: https://datatracker.ietf.org/doc/draft-deshmukh-mpls-frr-ext
Duration: 10 mins
Presenter: Vishnu Pavan Beeram
[Adrian]: how urgent early allocation? Can we wait until adoption
completes?
[Pavan]: can wait until adoption.
[Zafar]: concern about law of diminishing returns. Existing way is
policy on every node. Why we're introducing this?
[Pavan]: yes, but the number of TE profiles and fluidity is
increasing and this is becoming a necessary.
[Zafar]: what iter-op you need the early code point?
[Pavan]: preparing shipping of product.