From mboxrd@z Thu Jan 1 00:00:00 1970 From: Leonardo Balliache Date: Wed, 09 Jul 2003 02:58:07 +0000 Subject: RE: [LARTC] Question on prio qdisc Message-Id: List-Id: References: In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable To: lartc@vger.kernel.org Hi, Lars: At 10:10 a.m. 08/07/03 +0200, you wrote: > > > > each queue is an independent queue. Then if high priority packets are > > dropped is because the high priority queue has overflow, not because so= me > > (unique?) queue is full from low priority packets. > >I am little confused. If typed ifconfig, we can see "txqueuelen:100". >Will this imply that all three bands hold by prio are sharing this 100 >packages capacity, or can each of these three bands each occupy 100 >packages in its buffer. In the latter, this means prio can maximum occupy >300 packages... > >This problem will also imply HTB and other schedulers.. > > >Regards > >Lars Landmark I'm not very sure if the total queue length is 100 or 300 because I was searching the code and I can't find any information that tell me what the real length is. Because "ip link" shows me that qlen is 100, I have to suppose that total length is 100. But anyway, PRIO queing discipline principle calls that each priority queue is independent, then we can't have the prio 0 queue full of prio 1 or 2 packets (being the filters working well). It goes against the PRIO queuing discipline principle. In "Differentiated Service on Linux HOWTO" (work in progress) I present a PRIO queuing discipline explanation using some documentation taken from Juniper Networks. Have a look at http://opalsoft.net/qos. Also if you read about Cisco PQ the principle is identical. If we don't respect the principle, then the queue can be any sort of queue, but certainly, not a PRIO queue. Then it=B4s not posible to ask on PRIO for som= ething that drops an already enqueue packet to make run for a new arriving one. I suggest that configurations and tests made to reach that conclusions were= =20 revised. Best regards, Leonardo Balliache _______________________________________________ LARTC mailing list / LARTC@mailman.ds9a.nl http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO: http://lartc.org/