Subject: [NSIS] QSPEC: <Excess Treatment>

From: "Tschofenig, Hannes (NSN - FI/Espoo)" <[email-masked]>
Date: Sat, 15 Nov 2008 23:01:10 +0200

Hi all, 

"
   The default excess treatment in case that none is specified is that
   there are no guarantees to excess traffic, i.e. a QNE can do whatever
   it finds suitable.
" 

I think this sentence should make it clearer that "default" in this case
does not refer to a specific value of the <Excess Treatment> but rather
to the absence of the parameter. 

"
   When excess treatment is set to 'shape', it is expected that the
   QoS Desired object carries a TMOD parameter.  Excess traffic
   is to be shaped to this TMOD.  When the shaping causes
   unbounded queue growth at the shaper traffic can be dropped.  If
   excess treatment is set to 'shape' and no TMOD parameter is given,
   the E flag is set for the parameter and the reservation fails.
"

When a QoS Desired Object contains 2 TMODs, one for the regular QoS
treatment and another one for the shaping of excess traffic then how do
you differentiate the two? The text does not say anything about this
case. 

 When excess treatment is set to 'remark', the excess treatment
   parameter MUST carry the remark value, and the remark values and
   procedures MUST be specified in the QOSM specification document.  For
   example, packets may be remarked to drop or remarked to pertain to a
   particular QoS class (DSCP value).  In the latter case, remarking
   relates to a DiffServ model where packets arrive marked as belonging
   to a  certain QoS class/DSCP, and when they are identified as excess,
   they should then be remarked to a different QoS Class (DSCP value)
   indicated in the 'Remark Value', as follows:

   Remark Value (6 bits): indicates either drop (set to 0) or DSCP
                          value to remark packets to when identified as
                          excess

The value of 0 is unnecessary since this can already be accomplished by
value 0 for the Excess Trtmnt. 
Is the encoding of RFC 2474 used? 

Ciao
Hannes

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---

From: Gerald Ash <[email-masked]>
Date: Sun, 30 Nov 2008 11:18:23 -0800 (PST)

Hannes,
 
> to the absence of the parameter. 
 
OK.
 
> you differentiate the two? The text does not say anything about this
 
This should be specified by the applicable QOSM.  There are many possible instances of interacting QSPEC parameters where the QOSM will need to specify the intended behavior.

> Is the encoding of RFC 2474 used?
 
Yes.

> Hannes
 
Jerry