Subject: [Detnet-dp-dt] CoS and QoS

From: Jouni Korhonen <[email-masked]>
Date: Fri, 5 Feb 2016 12:37:34 -0800

Folks,

We dicussed this briefly during the call this week and what we actually 
need to clarify there. I would go along writing that CoS is a layer-2 
mechanism to differentiate traffic into few buckets (8 e.g., in case of 
Ethernet 802.1p/Q or MPLS label TC field) for specific per traffic class 
treatment/resource allocation and QoS is (typically at layer-3) in 
general a superset of CoS and a set of techniques to apply a specific 
treatment on layer-3 packets and eventually map a specific QoS to fewer 
CoS classes.

We could simplify here just thinking that CoS is a layer-2 and QoS is a 
layer-3 thingy. Makes sense?

- Jouni

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From: Lou Berger <[email-masked]>
Date: Fri, 5 Feb 2016 16:56:26 -0500

I think it's more than that and really orthogonal.  Put simply, IMO:
CoS - applies treatment and resources to a group of flows.  It typically
doesn't include any shaping, policing or flow admission mechanisms.
QoS - applies treatment and resources to a specific flows. It typically
includes some level of per flow resource accounting and may include flow
admission mechanisms and even shaping and policing.

I'll see if I can find text I've written in the past on this.
Lou

On 2/5/2016 3:37 PM, Jouni Korhonen wrote:
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