Re: [pcp] differentiating traffic, draft-wing-pcp-flowdata

[<[e-mail]>]

Hi Dan,

This is indeed an interesting piece of work...which has also its drawbacks;-) See the comment I made about the generic framework here: http://www.ietf.org/mail-archive/web/int-area/current/msg03627.html.

Targeting a perfect solution which does not suffer from limitations is not viable IMHO. This is why I'm seeing this work as a useful tool to be added to the existing toolkit. This work opens a new perspective which is worth to be considered by the WG. In addition to the flowdata work, I'm also suggesting to consider other work items such as:

* Use PCP to enforce DSCP remarking policies (http://tools.ietf.org/html/draft-boucadair-pcp-extensions-03#section-3). This is useful when the PCP Client is operated by the provider. This is an intra-domain case.
* Use PCP to discover the DSCP marking to be used for outbound packets: this option can be used with or without FLOWDATA option. The typical use case is where the PCP client is embedded in a CPE (not the host) and various marking policies are used at the access network. This is an intra-domain case.
 
Cheers,
Med  

>-----Message d'origine-----
>De : [e-mail] [mailto:[e-mail]] De la part de Dan
>Wing
>Envoyé : vendredi 26 juillet 2013 00:44
>À : [e-mail]
>Objet : [pcp] differentiating traffic, draft-wing-pcp-flowdata
>
>Many networks have insufficient access bandwidth and it is desirable to
>handle flows differently over that access link based on the flow's needs
>(high bandwidth, low loss, high delay) or if the flow is to a certain
>device or certain user ((living room television, tablet, mom/dad/kid).
>Hosts don't have a way to prioritize flows downstream (towards the host)
>and have poor capability to prioritize flows upstream, especially among the
>various hosts on the network.  Various solutions to this problem have been
>developed over the years (DSCP, RSVP, NSIS) but have drawbacks.
>
>I hope the problem described above resonates with people on this list.  If
>so, read on.
>
>
>In draft-wing-pcp-flowdata we propose a solution:  the host describes the
>flow characteristics to the network and the network indicates its
>(in)ability to accommodate the flow.  That flow description can be used by
>the default network, or propagated along the network.  For example in a
>home network the flow description can propagate from in-home CPE router to
>the ISP's access router, and in an enterprise network the flow description
>can propagate within the enterprise network and up to the ISP's access
>router.  When the flow characteristics are communicated to both sides of a
>resource-constrained link, the routers on both end can provide different
>packet forwarding treatment to the flow.
>
>The mechanism draft-wing-pcp-flowdata brings some advantages:
>
>  * incrementally deployable.  This can be implemented entirely within a
>subscriber's network without participation of their ISP, providing some
>value (but of course not as much value as being deployed by the ISP's
>access router).  Similarly, this can be implemented on the ISP's router and
>the host could signal directly to that ISP's router without needing support
>of the intermediate network.
>  * adaptive bit rate applications can improve user experience by avoiding
>attempts to exceed the network's upper bandwidth limit
>  * traffic differentiation can be per-"event" (e.g., streaming TV of the
>Olympics, VoIP call with an important customer), in addition to more
>traditional per-user or per-device or per-application.
>
>Details are in http://tools.ietf.org/html/draft-wing-pcp-flowdata.
>
>Comments welcome.
>-d
>
>
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