[Cats] Re: Fw: Introduction to the status of draft-fu-cats-oam-fw-05 and encourage more discussions

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Hi Shuai,

Thanks for your comments!

Thanks for your suggestions! We will add more clarifications on the security considerations in next version. 

Time synchronization depends on the measurement solution and protocol which is out of scope of this document. 
From my view, the time synchronization is required in case of unidirectional measurement (OWAMP, STAMP, IOAM, etc.) . It is usually not necessary for the bidirectional measurement (such as TWAMP).

Best Regards,
Quan



Original


From: 张帅(联通集团本部) <[e-mail]>
To: 熊泉00091065;
Cc: cats <[e-mail]>;
Date: 2026年06月05日 11:00
Subject: Fw: [Cats] Introduction to the status of draft-fu-cats-oam-fw-05 and encourage more discussions


Dear Authors，
Thank you for the introduction of draft-fu-cats-oam-fw-05. I have read the draft and have a few questions that I would like to bring to your attention:


1. Security Considerations 
I noticed that Section 7 ("Security Considerations") is currently a placeholder. Given the emphasis in Section 6.2 (A-REQ-3) on preventing malicious actors from injecting "fake" metrics to trigger sinkhole attacks, could you please elaborate on the planned threat model?
Will future revisions include a detailed analysis of potential vulnerabilities in the metric reporting channel?


2. Time Synchronization Requirements 
Section 5.1 and Section 6.1 discuss "Joint Performance Measurement" and the correlation of multi-layer OAM data to isolate faults. To accurately measure metrics like "total latency" (network transport time + service processing time) or to synchronize telemetry across different domains, precise time alignment is essential.


Does the CATS architecture assume a specific time synchronization mechanism (e.g., PTP, NTP)?

Should the framework include a requirement or recommendation regarding the precision of time synchronization (e.g., sub-millisecond or microsecond-level accuracy) to ensure the effectiveness of the "Joint Performance Measurement" described in Section 5.2.2?


Thanks in advance for your replying.
lT


Best Regards！
Shuai Zhang

 

发件人： xiong.quan
发送时间： 2026-05-28 15:36
收件人： cats-chairs; cats
主题： [Cats] Introduction to the status of draft-fu-cats-oam-fw-05 and encourage more discussions



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Dear All,

As suggested by the chairs, I'd like to provide a brief introduction to the status of this document to help everyone to better understand its content and encourage further feedback in the mailing list.

https://datatracker.ietf.org/doc/draft-fu-cats-oam-fw/05/

This document (draft-fu-cats-oam-fw-05) proposes an Operations, Administration, and Maintenance (OAM) framework for Computing-Aware Traffic Steering (CATS) systems. It addresses the limitations of traditional network-centric OAM by introducing a multidimensional approach that integrates both network and computing resource monitoring.

Motivation and Problem Statement:
The framework is designed to prevent "service black-holing," where traffic is directed to service instances that are network-reachable but computationally unresponsive. It enables real-time correlation of network metrics with computing metrics to support accurate steering decisions and ensure services are both reachable and performing as expected.

Key Components:
A four-layer OAM model: Link OAM (physical connectivity), Path OAM (transport paths), Instance OAM (service instance liveness and computing metrics), and Service OAM (end-to-end service delivery)
Two functional components: SI-OAM for service instance monitoring and SVC-OAM for end-to-end service verification
Comprehensive OAM requirements: aligned with the operational and management guidelines in [I-D.draft-opsarea-rfc5706bis]

This document has been presented at IETF #124 and #125. We sincerely appreciate the valuable feedback and suggestions received from Adrian Farrel, Erum Welling, Cheng Li, Peng Liu, Haomian Zheng, and other participants. The authors have revised the draft through multiple versions (00 to 05) to incorporate this feedback. Since the last presentation at IETF 125, no further comments have been raised.

The authors welcome additional review and constructive discussion, and we look forward to your feedback as we consider this draft for potential adoption by the CATS working group.Thanks!

Best Regards,
Quan