From: Mark Miller (markmiller@alltel.net)
Date: Tue Apr 15 2003 - 23:00:06 GMT-3
> Scott,
> I'm not sure what you're asking here, but I'll give it my best shot at
> answering this question.
>
> DSCP values are categorized into four 'Assured forwarding Classes, and
> one 'Expedited forwarding' class.
>
> Class 1 = AF11, AF12, AF13 -- maps to ip prec. 1
> Class 2 = AF 21, AF22,AF23 -- maps to ip prec 2
> Class 3 = AF31, AF32, AF33 -- maps to ip prec 3
> Class 4 = AF41, AF42, AF43 -- maps to ip prec 4
> Expedited Forwarding (EF) -- maps to ip prec 5
>
> The bit values for all of these assured forwarding (AF) can
> be 'summarized' into a specific class (Class 1, Class2, etc.).
>
> Now I'm not really sure about what you mean by "aggregate DSCP
> levels", but if you look at these bit values, that's how these
> different AF levels are put into different Classes.
>
> For example....
>
> AF21 010010
> AF22 010100
> AF23 010110
>
> These AF values are in Class2. The first three bits are the same to
> map to ip prec of 2, and are defined as the class selector code.....
> 010 =2, or Class 2. The last three bits define a prefered drop
> preference. AF23 will get dropped before AF22, etc.
>
> I may be WAY OFF here, but if I were asked to "aggregate" some
> dscp values, I would guess you were being asked to specify what
> class (Class 1, Class 2, etc) to put all of them in.
>
> In your example, however, you could not put these in one class
> because a value of 32 moves into the Class 4 space.
>
> I hope this helps. If I'm way off in left field from what you were asking
> please disregard and have a nice day.
>
> Mark :-)
>
>
>
>
>
> ----- Original Message -----
> From: "Scott M. Livingston" <scottl@sprinthosting.net>
> To: <ccielab@groupstudy.com>
> Sent: Tuesday, April 15, 2003 4:20 PM
> Subject: Aggregating DSCP values
>
>
> > I am going to keep digging at it, but I am stumped now. I believe I
> > understand how to aggregate precedence levels, but I am clueless on how
> > to aggregate DSCP values. Is there a way to do this? I have browsed some
> > url's and looked at the two RFC's, but nothing is jumping out at me yet.
> > Guess I have to dig a little deeper.
> >
> > Let us say there is a task to group DSCP 28 through 32. How would one do
> > this without having to create 5 ACL's for each value?
> >
> > Thank You,
> > scott
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