Re: QoS and DSCP

[Daniel Wagner <wagi@monom.org>]

> Together with some printks I see that the code in wme.c classify_1d does
> exactly the thing which it should. It returns the dscp value correctly.
> Using --set-dscp 0x18 classify_1d returns 3 and with --set-dscp-class 
> EF, classify_1d returns 5. 

Crap, that's not correct. I think I found the problem:

static unsigned int classify_1d(struct sk_buff *skb)
{
        ...

	if (dscp & 0x1c)
		return 0;

	return dscp >> 5;
}

--set-dscp 0x28 (precendence level 5) classify_1d returns the correct
value 5. 

Setting with --set-dscp-class EF the TOS field it will have value 0xb8 (10111000b)
which maps to 
Bit 7-2: DSCP
Bit 1-0: ECN (expliliciet congestion notifaction)

So the question is what the 'if' is for? 

stay tuned!

daniel