[tsvwg] draft-ietf-tsvwg-nqb-15.txt - Section 5.2. Traffic Protection (text as is)

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Hi Greg,

Section  5.2. Traffic Protection
-	draft: NQB PHB SHOULD support a "traffic protection" function...and either re-mark [offending] flows/packets as Default and reclassify them to the QB queue or discard the offending traffic.

Please discuss the consequences of both options, re-marking & reclassification as default QB on one side and discard on the other. 

-	draft: Such a function SHOULD be implemented in an objective and verifiable manner, basing its decisions upon the behavior of the flow rather than on application-layer constructs.
“flow” is neither specified nor defined by your draft (and the draft doesn’t refer to a specification of flow given by another document). 

Objectively verified against which requirements (a requirement which can be verified is, e.g.: a sending rate  SHOULD average at least the configured rate when measured over any
time interval equal to or longer than the time it takes to send an output link MTU sized packet at the configured rate).
The draft doesn’t contain neither a specification, nor a definition, what a flow is, and it doesn't determine requirements on flow rates, which can be verified. All it offers is descriptive text to the latter.

-	draft: it is RECOMMENDED that traffic protection algorithms base their decisions on the detection of actual queuing, as opposed to simply packet arrival rate or data rate.

The draft doesn’t specify or define what is meant by “actual queuing”. It also doesn’t provide a reference.

-	draft: The traffic protection function MUST be designed to fail gracefully in the case that the flow state is exhausted.

I’m surprised to find a MUST here, while the major part of the queue protection mechanism isn’t specified. But to me, this requirement is vague too, as the draft doesn’t specify what is meant by “failing gracefully, if flow state is exhausted”.

Regards,

Ruediger



-----Ursprüngliche Nachricht-----
Von: tsvwg <[e-mail]> Im Auftrag von [e-mail]
Gesendet: Donnerstag, 12. Januar 2023 01:34
An: [e-mail]
Cc: [e-mail]
Betreff: [tsvwg] I-D Action: draft-ietf-tsvwg-nqb-15.txt


A New Internet-Draft is available from the on-line Internet-Drafts directories.
This draft is a work item of the Transport Area Working Group WG of the IETF.

        Title           : A Non-Queue-Building Per-Hop Behavior (NQB PHB) for Differentiated Services
        Authors         : Greg White
                          Thomas Fossati
  Filename        : draft-ietf-tsvwg-nqb-15.txt
  Pages           : 25
  Date            : 2023-01-11

Abstract:
   This document specifies properties and characteristics of a Non-
   Queue-Building Per-Hop Behavior (NQB PHB).  The purpose of this NQB
   PHB is to provide a separate queue that enables smooth, low-data-
   rate, application-limited traffic flows, which would ordinarily share
   a queue with bursty and capacity-seeking traffic, to avoid the
   latency, latency variation and loss caused by such traffic.  This PHB
   is implemented without prioritization and can be implemented without
   rate policing, making it suitable for environments where the use of
   these features is restricted.  The NQB PHB has been developed
   primarily for use by access network segments, where queuing delays
   and queuing loss caused by Queue-Building protocols are manifested,
   but its use is not limited to such segments.  In particular,
   applications to cable broadband links, Wi-Fi links, and mobile
   network radio and core segments are discussed.  This document
   recommends a specific Differentiated Services Code Point (DSCP) to
   identify Non-Queue-Building flows.


The IETF datatracker status page for this draft is:
https://datatracker.ietf.org/doc/draft-ietf-tsvwg-nqb/

There is also an HTML version available at:
https://www.ietf.org/archive/id/draft-ietf-tsvwg-nqb-15.html

A diff from the previous version is available at:
https://author-tools.ietf.org/iddiff?url2=draft-ietf-tsvwg-nqb-15


Internet-Drafts are also available by rsync at rsync.ietf.org::internet-drafts