[altq 796] Re: newbie question diffserv interface configuration

[Kenjiro Cho <kjc@csl.sony.co.jp>]

Placi Flury wrote:
> I'm trying to set up a diffserv network (testbed) with altq3. Even after
> reading most of the documentation of altq, I have two remaining questions.
> 
> Q1. given an interface xl0, is it possible to define a conditioner for
> INCOMMING traffic e.g. (for a differv border router):

Yes, that's how diffserv traffic conditioners are supposed to work.

>  conditioner xl0 AF11_traffic <mark 0x28>
> 	filter xl0 AF11_traffic 0 0 2001 0 0 

This marks the same DSCP to all packets.
You should use trTCM for marking different drop precedence levels.

> and to define for OUTGOING traffic on the same interface
> 
>  class cbq xl0 AF11_class def_class borrow pbandwidth 20 prio
                                                           ^should be rio
> 	filter xl0 AF11_class 0 0 0 0 0 tos 0x28 tosmask 0xe4

> I tried it but I got the following error (maybe something is wrong with
> my installation):
> 
> # Segmentation fault (core dumped)

That's bad :)  If you can provide your altq.conf, I might be able to
reproduce the problem on my machine.

You can start with a sample config in the ALTQ release, and then,
remove lines you don't need.

[snip]

> Q2. Since I don't understand the rio 3 parameters, does anybody know where
> I could find documentation on it (except altq.conf and the source code,
> I'm not a good source coude reader, especially if I don't understand the
> basic principles of the implementation..)

It is briefly decribed in altq.conf(5).

	rio  low_min_th low_max_th low_inv_pmax \
	     medium_min_th medium_max_th medium_inv_pmax \
	     high_min_th high_max_th high_inv_pmax

RED uses min_th (minimum threshold), max_th (max threshold), and
inv_pmax (inverse of max drop probability).
RIO needs 3 sets of these parameters for 3 drop procedence levels.

-Kenjiro