Hi Etienne, while I have no real inside for your actual problem; but I do have to add something else. Back when I was using DSL I used the following addition to the definition of the root disc (for egress and ingress), to deal with the peculiarities of ATM based ADSL: stab overhead 18 mtu 2048 mpu 53 linklayer atm (there is a tc-stab manpage (http://manpages.ubuntu.com/manpages/precise/man8/tc-stab.8.html) to help you select the right value for overhead, mtu here only concerns the size table and not the interface mtu) If your DSL connection uses an underlaying ATM carrier (most old DSL connections do to my knowledge) this will help a lot, as due to ATM small packages will often carry a lot of padding that eats considerable portions of you bandwidth. the stab invocation will not change that bandwidth use, but will take it into account while shaping from your root disc. Otherwise you will a) overload your DSL link in spite of your plan to avoid that and b) the system will think and report a lower used bandwidth than true. Note should you opt to take hub inbuilt link layer atm options see (http://kerneltrap.org/mailarchive/linux-netdev/2010/7/7/6280676) Now some modern DSL variants do not use ATM as carrier anymore, notably some VDSL/VDSL2 use PTM-TC which does not have the same interesting structure as ATM (see http://www.ethernetinthefirstmile.com/articles/WTC2002.pdf) Also if you use hub people typically seem to use hub children as well (http://luxik.cdi.cz/~devik/qos/htb/manual/userg.htm) so maybe that causes the issues you have (see http://linux.die.net/man/8/tc-htb for amore current overview of the parameters)? hoping this helps somewhat Sebastian On May 27, 2012, at 5:41 AM, e-t172 wrote: > Hi, > > I'm trying to shape the traffic going out of my DSL link (verified 1 mbit upload) using Linux (3.2) tc, HTB, and PRIO. My Linux box is connected via a Gigabit Ethernet link to the ADSL modem. I want to limit the upload rate using HTB so my packets get queued at the Linux box and not at the modem, and then use PRIO to put packets into priority bands. > > So, I did this: > > tc qdisc add dev dsl root handle 1: htb default 1 > tc class add dev dsl parent 1: classid 1:1 htb rate 950kbit > tc qdisc add dev dsl parent 1:1 handle 2: prio bands 6 > tc qdisc add dev dsl parent 2:1 bfifo > tc qdisc add dev dsl parent 2:2 bfifo > tc qdisc add dev dsl parent 2:3 bfifo > tc qdisc add dev dsl parent 2:4 bfifo > tc qdisc add dev dsl parent 2:5 bfifo > tc qdisc add dev dsl parent 2:6 bfifo > > Problem is, as soon as I do that, my upload link slows down miserably. I'm getting approx. 25 kbit/s, which is *38 times* slower than what I should be getting (950 kbit/s), even though the link is unused. > > Interestingly, if I remove the PRIO qdisc but keep the HTB qdisc, then throughput goes up to approx. 550 kbit/s, which is better but still not what I should be getting. Again, the link is unused, so prioritization does not account for this behavior. > > Any idea what's wrong with what I'm doing? I've been using the exact same commands for years to shape an Ethernet link to 50 mbit/s without any issues, so I really have no idea why it doesn't work in this situation. > > Additional information: > > # tc -s -d qdisc ls dev dsl > qdisc htb 1: root refcnt 2 r2q 10 default 1 direct_packets_stat 0 ver 3.17 > Sent 447262 bytes 1168 pkt (dropped 90, overlimits 38 requeues 0) > backlog 0b 0p requeues 0 > qdisc prio 2: parent 1:1 bands 6 priomap 1 2 2 2 1 2 0 0 1 1 1 1 1 1 1 1 > Sent 447262 bytes 1168 pkt (dropped 90, overlimits 0 requeues 0) > backlog 0b 0p requeues 0 > qdisc bfifo 8043: parent 2:1 limit 1514b > Sent 84138 bytes 928 pkt (dropped 0, overlimits 0 requeues 0) > backlog 0b 0p requeues 0 > qdisc bfifo 8044: parent 2:2 limit 1514b > Sent 363124 bytes 240 pkt (dropped 90, overlimits 0 requeues 0) > backlog 0b 0p requeues 0 > qdisc bfifo 8045: parent 2:3 limit 1514b > Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0) > backlog 0b 0p requeues 0 > qdisc bfifo 8046: parent 2:4 limit 1514b > Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0) > backlog 0b 0p requeues 0 > qdisc bfifo 8047: parent 2:5 limit 1514b > Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0) > backlog 0b 0p requeues 0 > qdisc bfifo 8048: parent 2:6 limit 1514b > Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0) > backlog 0b 0p requeues 0 > > # tc -s -d class show dev dsl > class htb 1:1 root leaf 2: prio 0 quantum 11875 rate 950000bit ceil 950000bit burst 1599b/8 mpu 0b overhead 0b cburst 1599b/8 mpu 0b overhead 0b level 0 > Sent 478804 bytes 1316 pkt (dropped 90, overlimits 0 requeues 0) > rate 42232bit 17pps backlog 0b 0p requeues 0 > lended: 1316 borrowed: 0 giants: 0 > tokens: 195781 ctokens: 195781 > class prio 2:1 parent 2: leaf 8043: > Sent 97560 bytes 1064 pkt (dropped 0, overlimits 0 requeues 0) > backlog 0b 0p requeues 0 > class prio 2:2 parent 2: leaf 8044: > Sent 381244 bytes 252 pkt (dropped 90, overlimits 0 requeues 0) > backlog 0b 0p requeues 0 > class prio 2:3 parent 2: leaf 8045: > Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0) > backlog 0b 0p requeues 0 > class prio 2:4 parent 2: leaf 8046: > Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0) > backlog 0b 0p requeues 0 > class prio 2:5 parent 2: leaf 8047: > Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0) > backlog 0b 0p requeues 0 > class prio 2:6 parent 2: leaf 8048: > Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0) > backlog 0b 0p requeues 0 > > -- > Etienne Dechamps / e-t172 - AKE Group > Phone: +33 6 23 42 24 82 > -- > To unsubscribe from this list: send the line "unsubscribe lartc" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe lartc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
