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

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Fred,

thanks, I share your assessment. Draft NQB offers  a standard conforming option to get access to the combined resources of NQB and QB queue, iff a flow is classified as NQB and violates NQB requirements. The full consequences of that aren't discussed by the draft.

Regards,

Ruediger

-----Ursprüngliche Nachricht-----
Von: Fred Baker <[e-mail]> 
Gesendet: Sonntag, 12. März 2023 01:30
An: Greg White <[e-mail]>
Cc: Geib, Rüdiger <[e-mail]>; [e-mail]
Betreff: Re: [tsvwg] draft-ietf-tsvwg-nqb-15.txt - Section 5.2. Traffic Protection (text as is)



Sent using a machine that autocorrects in interesting ways...

> On Mar 11, 2023, at 4:05 PM, Greg White <[e-mail]> wrote:
> 
> [GW] Sections 6 & 12 already mention the consequences of both options on an application (and the consequences there are fairly obvious).  I guess you are asking more broadly, what are the consequences of PHB implementers choosing the re-marking/re-classification option vs choosing the discard option, in a game-theory sense?  For applications that are sensitive to packet loss, I suppose PHB implementations that choose the discard option would create a stronger disincentive for application mismarking, but on the other hand would likely create a greater degradation even for NQB-compliant applications in overload situations, as compared to PHB implementations that choose re-marking/re-classification. For applications that are out-of-order intolerant (i.e. treating a sequence gap the same as a packet loss), I suppose the two PHB implementations are roughly equivalent. 

Discarding is a measurable event if the packet contains something that can be treated as a sequence number. Dropping it into a different queue can improve the effective rate of the packet, or delay it, depending on the momentary statistics of the other queue; if the queue happens to be empty at that nanosecond, for example, it effectively adds the rates of the two queues for the duration f the packet.

I suspect your statement of the impact is somewhat cavalier.