From mboxrd@z Thu Jan 1 00:00:00 1970 From: Patrick McHardy Subject: Re: Network QoS support in applications Date: Tue, 26 Jan 2010 12:59:04 +0100 Message-ID: <4B5ED908.4030608@trash.net> References: <87k4v5nuej.fsf@purkki.valot.fi> <4B5ED254.7010104@trash.net> <877hr5nkx0.fsf@purkki.valot.fi> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: 7bit Cc: netdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-wireless-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Kalle Valo Return-path: In-Reply-To: <877hr5nkx0.fsf-ySPBbPOLdCfMApvqMRVM/A@public.gmane.org> Sender: linux-wireless-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: netdev.vger.kernel.org Kalle Valo wrote: > Patrick McHardy writes: > >>> Solution 2: SO_PRIORITY with values 256-263 >> You can actually encode any class handle in SO_PRIORITY, all classful >> qdiscs support classification based on this. > > But what values should I use in an application? There seems to n+1 > different ways to do it, but they all would be specific to my own > setup. In case of classful qdisc classification, the values need to match the class handles. > I'm after a universal solution, so that there is no need to modify > applications every time. I would assume that we have a set of rules > for this. If not, we definitely need one. Classful qdisc configuration is done by the administrator, so there is no universal solution. > Let's take a bittorrent client as an example. The traffic it generates > is not important and it doesn't matter if bittorrent packets have > lower priority compared to other streams. What SO_PRIORITY value > should all bittorrent clients to use to mark their packets as low > priority (for example background class from IEEE 802.1d Annex G). > > Another example is a VoIP application. The packets need to have as low > delay as possible, so they need to be prioritised very high (for > example voice class from 802.1d). What value should such application > use? If the device is using the default pfifo_fast qdisc, you can use values 6 and 7 to map to band 0 (highest priority), 0 and 8-15 to map to band 1 and 1-3 and 5 to map to band 2. For manually set up qdisc hierarchies you need to ask the user to specify a priority (or class handle) value. > Or should applications use something else than SO_PRIORITY? > > Any help is greatly welcomed here :) > -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html