[LARTC] Qos, HFSC and VoIP

[LARTC] Qos, HFSC and VoIP

[Romary Sonrier]

Hello, 
I'm using Linux kernel 2.6.x and tc (from iproute2 package).
I'm trying to use HTB or HFSC scheduler in order to limite the rate of outgoing packets and also in order to minimiez delay for RTP stream.
But I didn't suceed in having this 2 QoS services working.

I use Iptables in order to classify packets. Here is my HFSC  conf.
In fact the pings that i send from this box should be the most highly priorised packet, but there are delayed when i add load on the link (with a scp  upload).
What is strange is that the delay of thoses ping is not constant:
Does someone have an idea about this issue?

Thx for any help
romary

64 bytes from 10.10.0.10: icmp_seq=1 ttlc time\x10.4 ms
64 bytes from 10.10.0.10: icmp_seq=2 ttlc timeR.8 ms
64 bytes from 10.10.0.10: icmp_seq=3 ttlc time@.4 ms
64 bytes from 10.10.0.10: icmp_seq=4 ttlc timeê.1 ms
64 bytes from 10.10.0.10: icmp_seq=5 ttlc timew.6 ms
64 bytes from 10.10.0.10: icmp_seq=6 ttlc time\x127 ms
64 bytes from 10.10.0.10: icmp_seq=7 ttlc time\x177 ms
64 bytes from 10.10.0.10: icmp_seq=8 ttlc time"7 ms
64 bytes from 10.10.0.10: icmp_seq=9 ttlc time'7 ms
64 bytes from 10.10.0.10: icmp_seq\x10 ttlc time26 ms
64 bytes from 10.10.0.10: icmp_seq\x11 ttlc time\x11.5 ms<<=========="time hole"
64 bytes from 10.10.0.10: icmp_seq\x12 ttlc time\x11.0 ms
64 bytes from 10.10.0.10: icmp_seq\x13 ttlc timeC.6 ms
64 bytes from 10.10.0.10: icmp_seq\x14 ttlc timeì.7 ms
64 bytes from 10.10.0.10: icmp_seq\x15 ttlc time\x142 ms
64 bytes from 10.10.0.10: icmp_seq\x16 ttlc time\x136 ms
64 bytes from 10.10.0.10: icmp_seq\x17 ttlc time 6 ms
64 bytes from 10.10.0.10: icmp_seq\x18 ttlc time\x199 ms
64 bytes from 10.10.0.10: icmp_seq\x19 ttlc time$3 ms
64 bytes from 10.10.0.10: icmp_seq  ttlc time)3 ms
64 bytes from 10.10.0.10: icmp_seq! ttlc time43 ms
64 bytes from 10.10.0.10: icmp_seq" ttlc time".5 ms
64 bytes from 10.10.0.10: icmp_seq# ttlc time\x11.1 ms <<=========="time hole"
64 bytes from 10.10.0.10: icmp_seq$ ttlc time\x10.5 ms
64 bytes from 10.10.0.10: icmp_seq% ttlc timeH.4 ms
64 bytes from 10.10.0.10: icmp_seq& ttlc timeò.8 ms
64 bytes from 10.10.0.10: icmp_seq' ttlc time\x147 ms
64 bytes from 10.10.0.10: icmp_seq( ttlc time\x196 ms
64 bytes from 10.10.0.10: icmp_seq) ttlc time$6 ms
64 bytes from 10.10.0.10: icmp_seq0 ttlc time#4 ms
64 bytes from 10.10.0.10: icmp_seq1 ttlc time(4 ms
64 bytes from 10.10.0.10: icmp_seq2 ttlc time34 ms
64 bytes from 10.10.0.10: icmp_seq3 ttlc time\x13.4 ms<<=========="time hole"
64 bytes from 10.10.0.10: icmp_seq4 ttlc time\x10.1 ms
64 bytes from 10.10.0.10: icmp_seq5 ttlc timeP.6 ms
64 bytes from 10.10.0.10: icmp_seq6 ttlc time\x100 ms



=>tc -s -d qdisc show dev $MYDEV
>qdisc hfsc 1: default 7 
> Sent 179610 bytes 2299 pkts (dropped 0, overlimits 967)
>qdisc sfq 15:
> Sent 0 bytes 0 pkts (dropped 0, overlimits 0)
>qdisc sfq 16:
> Sent 0 bytes 0 pkts (dropped 0, overlimits 0)
>qdisc sfq 17:
> Sent 1857 bytes 24 pkts (dropped 0, overlimits 0)


=>tc -s -d class show dev $MYDEV
>class hfsc 1: root
> Sent 0 bytes 0 pkts (dropped 0, overlimits 0)
> period 0 level 2
>
>class hfsc 1:10 parent 1: sc m1 0bit d 0us m2 243208bit ul m1 0bit d 0us m2 243208bit
> Sent 0 bytes 0 pkts (dropped 0, overlimits 0)
> period 26 work 179610 bytes level 1
>
>class hfsc 1:1 parent 1:10 rt m1 0bit d 0us m2 2000bit
> Sent 173952 bytes 2232 pkts (dropped 0, overlimits 0)
> period 0 work 173952 bytes rtwork 173952 bytes level 0
>
>class hfsc 1:2 parent 1:10 rt m1 0bit d 0us m2 229136bit
> Sent 3649 bytes 41 pkts (dropped 0, overlimits 0)
> period 0 work 3649 bytes rtwork 3649 bytes level 0
>
>class hfsc 1:3 parent 1:10 ls m1 0bit d 0us m2 2408bit ul m1 0bit d 0us m2 192960bit
> Sent 152 bytes 2 pkts (dropped 0, overlimits 0)
> period 2 work 152 bytes level 0
>
>class hfsc 1:4 parent 1:10 ls m1 0bit d 0us m2 2408bit ul m1 0bit d 0us m2 192960bit
> Sent 0 bytes 0 pkts (dropped 0, overlimits 0)
> period 0 level 0
>
>class hfsc 1:5 parent 1:10 leaf 15: ls m1 0bit d 0us m2 2408bit ul m1 0bit d 0us m2 192960bit
> Sent 0 bytes 0 pkts (dropped 0, overlimits 0)
> period 0 level 0
>
>class hfsc 1:6 parent 1:10 leaf 16: ls m1 0bit d 0us m2 2408bit ul m1 0bit d 0us m2 192960bit
> Sent 0 bytes 0 pkts (dropped 0, overlimits 0)
> period 0 level 0
>
>class hfsc 1:7 parent 1:10 leaf 17: ls m1 0bit d 0us m2 2408bit ul m1 0bit d 0us m2 192960bit
> Sent 1857 bytes 24 pkts (dropped 0, overlimits 0)
> period 24 work 1857 bytes level 0
>



=>iptables -v -t mangle -L POSTROUTING
>1    35627   15M CLASSIFY   all  --  *      ppp0    0.0.0.0/0            0.0.0.0/0           CLASSIFY set 1:7
>2        0     0 CLASSIFY   tcp  --  *      ppp0    0.0.0.0/0            0.0.0.0/0           multiport dports 25,110,143,993 CLASSIFY set 1:6
>3        0     0 CLASSIFY   tcp  --  *      ppp0    0.0.0.0/0            0.0.0.0/0           multiport dports 80,443 CLASSIFY set 1:5
>4      233 14266 CLASSIFY   tcp  --  *      ppp0    0.0.0.0/0            0.0.0.0/0           tcp dpt:22 length 0:400 CLASSIFY set 1:4
>5     2717  228K CLASSIFY   icmp --  *      ppp0    0.0.0.0/0            0.0.0.0/0           CLASSIFY set 1:3
>6        2   152 CLASSIFY   udp  --  *      ppp0    0.0.0.0/0            0.0.0.0/0           multiport dports 123,53 CLASSIFY set 1:3
>7        0     0 CLASSIFY   tcp  --  *      ppp0    0.0.0.0/0            0.0.0.0/0           multiport dports 123,53 CLASSIFY set 1:3
>8    19261 1160K CLASSIFY   udp  --  *      ppp0    0.0.0.0/0            10.25.0.201         CLASSIFY set 1:2
>9      256 22364 CLASSIFY   udp  --  *      ppp0    0.0.0.0/0            10.22.0.200         CLASSIFY set 1:2
>10    2717  228K CLASSIFY   icmp --  *      ppp0    0.0.0.0/0            10.10.0.10          CLASSIFY set 1:1
>11       0     0 CLASSIFY   icmp --  *      ppp0    0.0.0.0/0            10.10.0.5           CLASSIFY set 1:1
>12    4200  302K CLASSIFY   udp  --  *      ppp0    0.0.0.0/0            0.0.0.0/0           udp dpt:520 CLASSIFY set 1:1
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Re: [LARTC] Qos, HFSC and VoIP

[Andy Furniss]

Romary Sonrier wrote:
> Hello, 
> I'm using Linux kernel 2.6.x and tc (from iproute2 package).
> I'm trying to use HTB or HFSC scheduler in order to limite the rate of outgoing packets and also in order to minimiez delay for RTP stream.
> But I didn't suceed in having this 2 QoS services working.
> 
> I use Iptables in order to classify packets. Here is my HFSC  conf.
> In fact the pings that i send from this box should be the most highly priorised packet, but there are delayed when i add load on the link (with a scp  upload).
> What is strange is that the delay of thoses ping is not constant:
> Does someone have an idea about this issue?

Try making the ul rates lower and see if that's it. The ping pattern 
could be because you are slightly over rate for ppp0, but when sfq 
perturbs (assuming perturb 10) the packet reordering makes the tcp back 
off enough for the queue to clear.

I know you only have sfq on ls - which is OK, but don't put sfq/prio on 
an rt or sc leaf as hfsc dequeues/requeues for these to see next packet 
length. In the case of sfq/prio it will/may not be that packet that gets 
dequeued.

I also notice your rates add up to > ul.

Andy.
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