Re: [Diffserv-interest] Diffserv, AF, and EF question

Brian E Carpenter <brian@hursley.ibm.com> Wed, 12 September 2001 15:19 UTC

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Date: Wed, 12 Sep 2001 10:13:11 -0500
From: Brian E Carpenter <brian@hursley.ibm.com>
Organization: IBM
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Subject: Re: [Diffserv-interest] Diffserv, AF, and EF question
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Karen Gray wrote:
> 
> First, can someone please tell me how EF and AF are implemented in
> DiffServ? I know that there are 4 physical queues.  

No, there are as many queues as you happen to need acording to
how many PHBs are configured on a given interface. In theory that is
any number between 1 and 64 (meximum number of DSCP values).

> Are these queues AF
> or EF?

Depends on local configuration
> 
> Second, does anyone know what the officially recommended scheduling
> method is for AF: RR, WRR, etc?

There is no recommendation. It's an implementation decision, not a
standards issue. The standard simply requires an implementation that
meets the PHB group definition. If you look at the MIB, you will see
that even the choice of scheduler is a configuration choice.

   Brian

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