Re: [Tsv-art] [Detnet] Congestion Protection name change (was: Re: Tsvart last call review of draft-ietf-detnet-architecture-08)

["qiangli (D)" <[e-mail]>]

Current service layer focuses on packet loss control, no or nearly no delay control solutions. My personal feeling is --- it’s inappropriate to name a packet loss control focused layer with “detnet service layer” or “detnet service level guarantee layer”.


Best regards,

Cristina QIANG

From: detnet [mailto:[e-mail]] On Behalf Of Andrew G. Malis
Sent: Monday, December 10, 2018 11:28 PM
To: Pascal Thubert (pthubert) <[e-mail]>
Cc: Lou Berger <[e-mail]>; [e-mail]; [e-mail]; János Farkas <[e-mail]>; Transport Area Review Team <[e-mail]>; detnet WG <[e-mail]>
Subject: Re: [Detnet] Congestion Protection name change (was: Re: Tsvart last call review of draft-ietf-detnet-architecture-08)

Since we're guaranteeing a particular level of service as generally used in SLAs, I would prefer the term "service level guarantee", which includes bounds on packet delay and packet loss.

If we want, we can extend the definition to include examples of the mechanisms used to provide the guarantee, such as queue management, link and node resource management, shaping, preemption, scheduling, and so on, but we don't have to.

Cheers,
Andy

On Mon, Dec 10, 2018 at 9:48 AM Pascal Thubert (pthubert) <[e-mail]<mailto:[e-mail]>> wrote:
The problem János is that we do not only avoid loss. We also control latency. So "queuing loss" is too limitation.
We are protecting the resources that are necessary, or providing guarantees that they are available. To provide the service.
Maybe "service guarantees" could be good?
Pascal

> -----Original Message-----
> From: János Farkas <[e-mail]<mailto:[e-mail]>>
> Sent: lundi 10 décembre 2018 18:30
> To: Lou Berger <[e-mail]<mailto:[e-mail]>>; Scharf, Michael <Michael.Scharf@hs-
<mailto:Michael.Scharf@hs-%0b>> esslingen.de<http://esslingen.de>>
> Cc: tsv-art@ietf..org<mailto:[e-mail]>; [e-mail]<mailto:[e-mail]>; draft-ietf-detnet-
> [e-mail]<mailto:[e-mail]>
> Subject: Congestion Protection name change (was: Re: [Detnet] Tsvart last call
> review of draft-ietf-detnet-architecture-08)
>
> Hi,
>
> As I understand, there is confusion around two DetNet terms.
> We are removing "transport".
>
> The other one is "congestion" and "congestion protection".
>
> Brief description of congestion protection in Section 3.1:
>
>     Congestion protection operates by allocating resources along the path
>     of a DetNet flow, e.g., buffer space or link bandwidth. Congestion
>     protection greatly reduces, or even eliminates entirely, packet loss
>     due to output packet congestion within the network, but it can only
>     be supplied to a DetNet flow that is limited at the source to a
>     maximum packet size and transmission rate.  Note that congestion
>     protection provided via congestion detection and notification is
>     explicitly excluded from consideration in DetNet, as it serves a
>     different set of applications.
>
>     Congestion protection addresses two of the DetNet QoS requirements:
>     latency and packet loss.  Given that DetNet nodes have a finite
>     amount of buffer space, congestion protection necessarily results in
>     a maximum end-to-end latency.  It also addresses the largest
>     contribution to packet loss, which is buffer congestion.
>
> Detailed description is in Section 3.2.1.
>
> We wanted to have a brief collective term for the mechanisms used to avoid
> queuing related packet loss (including buffer overflow etc.).
>
> Based on the discussions, we should have a term that does not include
> "congestion".
> ("Service Protection" is another DetNet term, hence we may consider a term
> without "protection" to minimize confusion.)
>
> I suggest to replace "congestion protection" with "queuing loss avoidance".
>
> After agreeing in the terminology cahnge (if any), the text has to be updated
> accordingly.
>
> What do you think?
>
> Best regards,
> Janos