From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stef Coene Date: Thu, 31 Jul 2003 09:46:32 +0000 Subject: Re: [LARTC] shaping incoming with ingress Message-Id: List-Id: References: In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: lartc@vger.kernel.org On Thursday 31 July 2003 05:00, Martin A. Brown wrote: > Good questions Damion, > > : I've noticed as of late, everyone saying 'you can't shape incoming > : traffic' but the best solution is to use the imq device. > > Well....(you'll love this) the reason everyone is saying "you can't shape > incoming traffic" is because you can't shape incoming traffic (without > IMQ). > > Well, in short, what we're really saying is that you can't control what > you receive (without IMQ). As the recipient of frames/packets, you have > no control over how fast they arrive in your device's input queue. You can shape outgoing packets because they are queued in a buffer before they are sended out. You can shape because you can reorder packets in that buffer. Incoming packets are not buffered, so you can't change the order. > : what happened to ingress /policer usage? is this not recommended > : anymore? > > There's nothing at all wrong with using an ingress policer. I don't > believe it's possible to attach any classes to the ingress qdisc*. That > is, the ingress qdisc only exists to allow the user to police inbound > traffic. > > So, using the ingress qdisc as a dummy qdisc against which to attach a > policing filter (which drops traffic over a given rate) is the only use of > the ingress qdisc. Indeed. And policing is not shaping. Policing is rate limiting while shaping can do more. For example, shaping can borrow unused bandwidth in a controlled way between different flows. Stef -- stef.coene@docum.org "Using Linux as bandwidth manager" http://www.docum.org/ #lartc @ irc.oftc.net _______________________________________________ LARTC mailing list / LARTC@mailman.ds9a.nl http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO: http://lartc.org/