AW: Does tc-prio really work as advertised?
> So, are you still sure you've tested such a case? Well, the problem that triggered my investigation was that the OLSR daemon (www.olsr.org) calculates the quality of a link according to the packet loss for LQ HELLO packets (UDP broadcast packets). To prevent other traffic from interfering with the LQ calculation, olsrd sends the HELLO packets with a TOS value of 0x10 (minimize delay). This should give them the highest priority. What I saw was a degrading Link quality with more user traffic over a link. The LQ fell so far that olsrd judged the other host unreachable and deleted the routing entry. The user traffic in question was iperf (TOS value 0x00). The OLSR traffic was obviously generated locally (not forwarded). You claim, that the TOS value for locally generated traffic does not influence its priority? Now I THINK that I did my tests both, for forwarded and for local traffic, but I'll redo my tests to make sure. -- Regards and thanks for taking an interest Joerg __ Ihr erstes Baby? Holen Sie sich Tipps von anderen Eltern. www.yahoo.de/clever - To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: AW: Does tc-prio really work as advertised?
Joerg Pommnitz wrote: > It works fine here, I'm guessing that Jörg is using an old kernel > version that had a bug in prio classification without filters. This is 2.6.20.21, from 17-Oct-2007. Yes, that version is broken. I think it was fixed in 2.6.22 or 2.6.23. - To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
AW: Does tc-prio really work as advertised?
> It works fine here, I'm guessing that Jörg is using an old kernel > version that had a bug in prio classification without filters. This is 2.6.20.21, from 17-Oct-2007. -- Regards Joerg __ Ihre erste Baustelle? Wissenswertes für Bastler und Hobby Handwerker. www.yahoo.de/clever - To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
AW: Does tc-prio really work as advertised?
Jarek, this is all about outgoing packets, e.g. egress to use your word. It doesn't matter whether the packets are originated locally or whether the packets are forwarded from another host (I tried both). To restate the problem: according to my observations the prio qdisc (and probably pfifo_fast, but I couldn't observe this) does not prioritize at all and always uses the band indicated by the first entry in the priomap. By default the priomap looks like this: qdisc prio 1: dev eth1 bands 3 priomap 1 2 2 2 1 2 0 0 1 1 1 1 1 1 1 1 there are 3 bands (1:1, 1:2 and 1:3). In theory the traffic should go through the different bands according to the TOS value of the packets. My observation is, that the traffic always uses the band pointed to by the first entry in the priomap. This value is 1 by default, so all traffic goes through band 1:2. Now it's entirely possible that I did something stupid, but nobody came forward to show me the error of my ways (neither here nor on the lartc list). -- Regards Joerg - Ursprüngliche Mail Von: Jarek Poplawski <[EMAIL PROTECTED]> An: Joerg Pommnitz <[EMAIL PROTECTED]> CC: netdev@vger.kernel.org Gesendet: Dienstag, den 27. November 2007, 10:58:38 Uhr Betreff: Re: Does tc-prio really work as advertised? On Tue, Nov 27, 2007 at 01:28:43AM -0800, Joerg Pommnitz wrote: > Jarek, > iptables chains (this is what I think you are referring to) are not the > issue. Yes, but this could (wrongly) look like this according to my 1-st message. > This > is about the qdisc that sits immediately over the device driver and decides > the > order waiting packets are sent over the line/air/carrier pigeon/... . > My suspicion is that skb->priority used to be set to a value that derived > from the > TOS bits. Then something changed and nobody noticed. I'm not sure of your problem: did you try this on a box which gets packets with TOS set earlier, does forwarding, and uses this prio on egress? If so, and this doesn't work, then you are right something could be wrong. Regards, Jarek P. __ Ihr erstes Baby? Holen Sie sich Tipps von anderen Eltern. www.yahoo.de/clever - To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
