**Session Date/Time:** 21 Mar 2022 09:00

# ippm

## Summary

The IP Performance Measurement (IPPM) working group met at IETF 113 for a hybrid session. The session focused on updates to several active working group documents, including the Capacity Metric Protocol, Responsiveness under Working Conditions, Echo Request Reply for IOM, IOM Data Integrity, IOM Deployment, IOM YANG, Explicit Flow Measurements, and SRPM Extensions. The group also discussed several proposed new work items: PDMv2, Hybrid Two-Step Collection & Transport, Precision Availability Metrics, OT-RAMP on LAG, and two older IOM data export drafts. Key discussions revolved around implementation experiences, clarifying definitions, security considerations, and determining next steps for adoption and progression of various drafts.

## Key Discussion Points

*   **Capacity Metric Protocol (CMP):** Updates included server admission control, randomized payload option, optional start rate in load adjustment, and security mode reductions. Call for early security area review.
*   **Responsiveness under Working Conditions:** Significant implementation experience was shared by Apple and the University of Cincinnati, highlighting interoperability successes and lessons learned regarding HTTP/2 connections and TCP pooling. Discussions clarified "working conditions" (realistic, worst-case HTTP/2 traffic) and "interpreting results" (exposing bufferbloat in network and end-host stacks, using separate connections for root cause analysis).
*   **Echo Request Reply for IOM:** Clarified its continued need in limited domains where IOM device control and explicit paths are not guaranteed. Rejected using ICMP to carry YANG-derived information. Defined specific security requirements for ICMPv6 and other methods.
*   **IOM Data Integrity:** Scope clarified to IOM data fields (not headers). Algorithms made more generic. Direct Export option removed. Feedback sought on meeting original problem statement.
*   **IOM Deployment:** Document remains stable, with no new feedback. Authors are aggregating deployment experiences from new kernel and VPP implementations.
*   **IOM YANG:** Added detailed parameters to `iom-info`, aligned with latest IOM data draft, and general YANG module cleanup. Request for YANG Doctor review.
*   **Explicit Flow Measurements (EFM):** Collaborations expanded with Technion University. Awaiting extensive review from an independent implementation, which will inform updates on delay bit description, token mechanisms, and measurement duration trade-offs. Discussion on potential for WG Last Call before wider adoption in other WGs.
*   **SRPM Extensions for SR Networks:** Updated Reflect-around-destination flag usage and added a structured sub-TLV for SRv6. Interest in interoperability testing and an early IANA assignment.
*   **PDMv2:** Presented progress on a lightweight registration protocol for PDMv2, focusing on authentication, authorization, and shared context generation using HPKE. Strong enterprise and cryptographer interest was noted.
*   **Hybrid Two-Step Collection & Transport:** Proposed a method for on-path telemetry using separate follow-up packets, offering more accurate, flexible, and secure measurement collection, including point-to-multipoint and upstream modes.
*   **Precision Availability Metrics (PAM):** Merged documents proposing metrics to express service availability relative to SLOs. Defined key concepts like Pam Interval, Error Interval, Severely Errored Interval, and availability states.
*   **OT-RAMP on LAG:** Proposed extensions for TWAMP and STAMP to measure performance metrics on individual member links of a Link Aggregation Group (LAG) using "micro-sessions" and associated identifiers.
*   **Old IOM Data Export Drafts (EtherType, Raw Export):** Discussed the relevance and potential progression of two older drafts for carrying IOM data using EtherType (e.g., for GRE/v4) and for raw IPFIX export of IOM data. Questions raised about author availability and community interest for adoption.

## Decisions and Action Items

*   **Capacity Metric Protocol:**
    *   Chairs to request an early security area review.
    *   Chairs to add a pointer to the open-source implementation (Open Broadband project on GitHub, UDP ST reference) to the DataTracker entry for the draft.
*   **Echo Request Reply for IOM:**
    *   Chairs will discuss internally regarding the request for Working Group Last Call and get back to the authors.
*   **IOM Data Integrity:**
    *   Authors and chairs will solicit further feedback from the working group, particularly from those who originally inspired the document, to ensure it meets the intended goals.
*   **IOM YANG:**
    *   Chairs to request a YANG Doctor review.
    *   The decision for Working Group Last Call will be made after the YANG Doctor review.
*   **Explicit Flow Measurements:**
    *   Chairs suggested considering a Working Group Last Call, and then sending a note to the Quick Working Group to solicit feedback before final publication.
*   **SRPM Extensions for SR Networks:**
    *   Rakesh Gandhi to send an email to the chairs requesting an early IANA assignment.
*   **PDMv2:**
    *   Chairs will consider the request for Working Group adoption. If adopted, an early security area review will be requested due to the security-sensitive nature of the work.
*   **Old IOM Data Export Drafts:**
    *   Frank Brockners will send an email to the mailing list to gauge community interest in progressing or sunsetting these drafts, and to identify potential new authors/drivers if interest exists.

## Next Steps

*   Authors of all drafts are encouraged to address feedback received during the meeting and on the mailing list.
*   Working Group members are encouraged to review the updated drafts and provide constructive comments on the mailing list.
*   Chairs will follow up on the requested reviews and working group adoption calls as decided.