Re: [Dart] WGLC: draft-ietf-dart-dscp-rtp-02

<> Thu, 14 August 2014 12:08 UTC

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Subject: Re: [Dart] WGLC: draft-ietf-dart-dscp-rtp-02
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Hi Gorry,

the following text will likely appear in the next version of my diffserv-intercon draft. The more DSCPs appear in a flow which aren't deployed end-to-end for the corresponding PHB, the more often one of the scenarios will be encountered.

The following scenarios start from a domain sending 
IP traffic using a PHB and a corresponding DSCP to an interconnected 
domain. The receiving domain may
-	Support the PHB and offer the same corresponding DSCP
-	Not support the PHB and use the DSCP for a different PHB
-	Not support the PHB and not use the DSCP
-	Support the PHB with a differing DSCP, and the DSCP of the
       sending domain is not used for another PHB
-	Support the PHB with a differing DSCP, and the DSCP of the
       sending domain is used for another PHB

Another question to be answered then is how a network provider will treat unrecognized or unexpected DSCPs received at network boundaries.



-----Ursprüngliche Nachricht-----
Von: Dart [] Im Auftrag von Gorry Fairhurst
Gesendet: Mittwoch, 13. August 2014 22:33
Betreff: [Dart] WGLC: draft-ietf-dart-dscp-rtp-02

I can see good points raised on the details, instead I have some questions about the overall document strcuture:


(2) I don't know if the document's goal is also to make transport recommendations for using multiple code points - i.e.things such as must be robust to the network changing a DSCP; needs to independently verify that a particular DCSP is not being black-holed, needs to not imply relative precedence when interpreting loss or marking of packets for a flow using multiple DCSPs etc. ???

If these are out of scope, then maybe the document should say that this particular document does not provide this sort of guidance.


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