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

[Greg White <[e-mail]>]

Hi Ruediger,

I wonder if you could provide some responses to my questions below (and which I reiterated in my response to Fred yesterday).
I'm not disagreeing with you that more could be said, but statements like "full consequences" gives me the impression that I could make a lot of attempts and still not make you happy.
In particular, is the text that I wrote in response to Fred along the lines of what you are asking for?

-Greg


On 3/13/23, 3:07 AM, "[e-mail] <mailto:[e-mail]>" <[e-mail] <mailto:[e-mail]>> wrote:


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] <mailto:[e-mail]>> 
Gesendet: Sonntag, 12. März 2023 01:30
An: Greg White <[e-mail] <mailto:[e-mail]>>
Cc: Geib, Rüdiger <[e-mail] <mailto:[e-mail]>>; [e-mail] <mailto:[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] <mailto:[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.