Re: [Cerowrt-devel] Correct syntax for cake commands and atm issues.

[Alan Jenkins <alan.christopher.jenkins@gmail.com>]

On 10/07/15 20:45, Fred Stratton wrote:
> These are the latest scripts,  AFAIK
>
> no overhead allowance. I note.
>

Excellent point.  There is, but SQM uses "tc stab" for it by default, 
and there's no way to read that out.

To test using the overhead code in cake, add

     option linklayer_adaptation_mechanism 'cake'

>
>
> On 10/07/15 20:40, Sebastian Moeller wrote:
>> Hi Fred,
>>
>>
>> On Jul 10, 2015, at 21:34 , Fred Stratton <fredstratton@imap.cc> wrote:
>>
>>> bridge sync is circa 10 000 kbit/s
>>>
>>> with the cake option in sqm enabled
>>>
>>> config queue 'eth1'
>>>     option qdisc_advanced '0'
>>>     option enabled '1'
>>>     option interface 'pppoe-wan'
>>>     option upload '850'
>>>     option qdisc 'cake'
>>>     option script 'simple_pppoe.qos'
>>>     option linklayer 'atm'
>>>     option overhead '40'
>>>     option download ‘8500'
>>     So this looks reasonable. Then again, if the DSLAM is under 
>> provisioned/oversubscribed (= congested) shaping uypur DSL link might 
>> not fix all buffer bloat..
>>
>>> tc -s qdisc show dev pppoe-wan
>>> qdisc htb 1: root refcnt 2 r2q 10 default 12 direct_packets_stat 0 
>>> direct_qlen 3
>>> Sent 101336 bytes 440 pkt (dropped 2, overlimits 66 requeues 0)
>>> backlog 0b 0p requeues 0
>>> qdisc cake 110: parent 1:11 unlimited diffserv4 flows raw
>>> Sent 4399 bytes 25 pkt (dropped 0, overlimits 0 requeues 0)
>>> backlog 0b 0p requeues 0
>>>            Class 0     Class 1     Class 2     Class 3
>>>   rate          0bit        0bit        0bit        0bit
>>>   target       5.0ms       5.0ms       5.0ms       5.0ms
>>> interval     100.0ms     100.0ms     100.0ms     100.0ms
>>> Pk delay         0us         0us         7us         2us
>>> Av delay         0us         0us         0us         0us
>>> Sp delay         0us         0us         0us         0us
>>>   pkts             0           0          22           3
>>> way inds           0           0           0           0
>>> way miss           0           0          22           2
>>> way cols           0           0           0           0
>>>   bytes            0           0        3392        1007
>>>   drops            0           0           0           0
>>>   marks            0           0           0           0
>>> qdisc cake 120: parent 1:12 unlimited diffserv4 flows raw
>>> Sent 96937 bytes 415 pkt (dropped 2, overlimits 0 requeues 0)
>>> backlog 0b 0p requeues 0
>>>            Class 0     Class 1     Class 2     Class 3
>>>   rate          0bit        0bit        0bit        0bit
>>>   target       5.0ms       5.0ms       5.0ms       5.0ms
>>> interval     100.0ms     100.0ms     100.0ms     100.0ms
>>> Pk delay         0us      28.0ms         0us         0us
>>> Av delay         0us       1.2ms         0us         0us
>>> Sp delay         0us         4us         0us         0us
>>>   pkts             0         417           0           0
>>> way inds           0           0           0           0
>>> way miss           0          23           0           0
>>> way cols           0           0           0           0
>>>   bytes            0       98951           0           0
>>>   drops            0           2           0           0
>>>   marks            0           0           0           0
>>> qdisc cake 130: parent 1:13 unlimited diffserv4 flows raw
>>> Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0)
>>> backlog 0b 0p requeues 0
>>>            Class 0     Class 1     Class 2     Class 3
>>>   rate          0bit        0bit        0bit        0bit
>>>   target       5.0ms       5.0ms       5.0ms       5.0ms
>>> interval     100.0ms     100.0ms     100.0ms     100.0ms
>>> Pk delay         0us         0us         0us         0us
>>> Av delay         0us         0us         0us         0us
>>> Sp delay         0us         0us         0us         0us
>>>   pkts             0           0           0           0
>>> way inds           0           0           0           0
>>> way miss           0           0           0           0
>>> way cols           0           0           0           0
>>>   bytes            0           0           0           0
>>>   drops            0           0           0           0
>>>   marks            0           0           0           0
>>> qdisc cake 140: parent 1:14 unlimited diffserv4 flows raw
>>> Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0)
>>> backlog 0b 0p requeues 0
>>>            Class 0     Class 1     Class 2     Class 3
>>>   rate          0bit        0bit        0bit        0bit
>>>   target       5.0ms       5.0ms       5.0ms       5.0ms
>>> interval     100.0ms     100.0ms     100.0ms     100.0ms
>>> Pk delay         0us         0us         0us         0us
>>> Av delay         0us         0us         0us         0us
>>> Sp delay         0us         0us         0us         0us
>>>   pkts             0           0           0           0
>>> way inds           0           0           0           0
>>> way miss           0           0           0           0
>>> way cols           0           0           0           0
>>>   bytes            0           0           0           0
>>>   drops            0           0           0           0
>>>   marks            0           0           0           0
>>> qdisc ingress ffff: parent ffff:fff1 ----------------
>>> Sent 273341 bytes 435 pkt (dropped 0, overlimits 0 requeues 0)
>>> backlog 0b 0p requeues 0
>>     But this is the hallmark of out of date sqm-scripts, this just 
>> uses cake as leaf qdisc and keeps HTB as the main shaper; a 
>> configuration that is useful for testing. I assume this is the old 
>> set of sqm-scripts not the update I just sent as attachment? If so 
>> could you retry with the newer scripts, please?
>>
>> Best Regards
>>     Sebastian
>>
>>>
>>>
>>>
>>> On 10/07/15 19:46, Sebastian Moeller wrote:
>>>> Hi Fred,
>>>>
>>>> your results seem to indicate that cake is not active at all, as 
>>>> the latency under load is abysmal (a quick check is to look at the 
>>>> median in relation to the min and the 90% number, in your examples 
>>>> all of these are terrible). Could you please post the result of the 
>>>> following commands on your router:
>>>> 1) cat /etc/config/sqm
>>>> 2) tc -d qdisc
>>>> 3) tc -d class show dev pppoe-wan
>>>> 4) tc -d class show dev ifb4pppoe-wqn
>>>> 5) /etc/init.d/sqm stop
>>>> 6) /etc/init.d/sqm start
>>>>
>>>> hopefully these give some insight what might have happened.
>>>>
>>>> And finally I would love to learn the output of:
>>>> sh betterspeedtest.sh -4 -H netperf-eu.bufferbloat.net -t 150 -p 
>>>> netperf-eu.bufferbloat.net -n 4 ; sh netperfrunner.sh -4 -H 
>>>> netperf-eu.bufferbloat.net -t 150 -p netperf-eu.bufferbloat.net -n 4
>>>>
>>>>
>>>> Many Thanks & Best Regards
>>>>     Sebastian
>>>>
>>>> On Jul 10, 2015, at 20:25 , Fred Stratton <fredstratton@imap.cc> 
>>>> wrote:
>>>>
>>>>> By your command
>>>>> Rebooted to rerun qdisc script, rather than changing qdiscs from 
>>>>> the command-line, so suboptimal process as end-point changed.
>>>>>
>>>>> script configuring qdiscs and overhead 40 on
>>>>>
>>>>> sh netperfrunner.sh -H netperf-eu.bufferbloat.net -p 2.96.48.1
>>>>> 2015-07-10 18:22:08 Testing netperf-eu.bufferbloat.net (ipv4) with 
>>>>> 4 streams down and up while pinging 2.96.48.1. Takes about 60 
>>>>> seconds.
>>>>> Download:  6.73 Mbps
>>>>>    Upload:  0.58 Mbps
>>>>>   Latency: (in msec, 62 pings, 0.00% packet loss)
>>>>>       Min: 24.094
>>>>>     10pct: 172.654
>>>>>    Median: 260.563
>>>>>       Avg: 253.580
>>>>>     90pct: 330.003
>>>>>       Max: 411.145
>>>>>
>>>>> script configuring qdiscs on flows raw
>>>>>
>>>>> sh netperfrunner.sh -H netperf-eu.bufferbloat.net -p
>>>>> 78.145.32.1
>>>>> 2015-07-10 18:49:21 Testing netperf-eu.bufferbloat.net (ipv4) with 
>>>>> 4 streams down and up while pinging 78.145.32.1. Takes about 60 
>>>>> seconds.
>>>>> Download:  6.75 Mbps
>>>>>    Upload:  0.59 Mbps
>>>>>   Latency: (in msec, 59 pings, 0.00% packet loss)
>>>>>       Min: 23.605
>>>>>     10pct: 169.789
>>>>>    Median: 282.155
>>>>>       Avg: 267.099
>>>>>     90pct: 333.283
>>>>>       Max: 376.509
>>>>>
>>>>> script configuring qdiscs and overhead 36 on
>>>>>
>>>>> sh netperfrunner.sh -H netperf-eu.bufferbloat.net -p
>>>>> 80.44.96.1
>>>>> 2015-07-10 19:20:18 Testing netperf-eu.bufferbloat.net (ipv4) with 
>>>>> 4 streams down and up while pinging 80.44.96.1. Takes about 60 
>>>>> seconds.
>>>>> Download:  6.56 Mbps
>>>>>    Upload:  0.59 Mbps
>>>>>   Latency: (in msec, 62 pings, 0.00% packet loss)
>>>>>       Min: 22.975
>>>>>     10pct: 195.473
>>>>>    Median: 281.756
>>>>>       Avg: 271.609
>>>>>     90pct: 342.130
>>>>>       Max: 398.573
>>>>>
>>>>>
>>>>> On 10/07/15 16:19, Alan Jenkins wrote:
>>>>>> I'm glad to hear there's a working version (even if it's not in 
>>>>>> the current build :).
>>>>>>
>>>>>> Do you have measurable improvements with overhead configured 
>>>>>> (v.s. unconfigured)?
>>>>>>
>>>>>> I've used netperfrunner from CeroWrtScripts, e.g.
>>>>>>
>>>>>> sh netperfrunner.sh -H netperf-eu.bufferbloat.net -p $ISP_ROUTER
>>>>>>
>>>>>> I believe accounting for overhead helps on this two-way test, 
>>>>>> because a) it saturates the uplink b) about half that bandwidth 
>>>>>> is tiny ack packets (depending on bandwidth asymmetry).  And 
>>>>>> small packets have proportionally high overhead.
>>>>>>
>>>>>> (But it seems to only make a small difference for me, which 
>>>>>> always surprises Seb).
>>>>>>
>>>>>> Alan
>>>>>>
>>>>>> On 10/07/15 15:52, Fred Stratton wrote:
>>>>>>> You are absolutely correct.
>>>>>>>
>>>>>>> I tried both a numeric overhead value, and alternatively 
>>>>>>> 'pppoe-vcmux'
>>>>>>> and 'ether-fcs' in the build I crafted based on r46006, which is 
>>>>>>> lupin
>>>>>>> undeclared version 2. Everything works as stated.
>>>>>>>
>>>>>>> On lupin undeclared version 4, the current release based on 
>>>>>>> r46117, the
>>>>>>> values were not recognised.
>>>>>>>
>>>>>>> Thank you.
>>>>>>>
>>>>>>> I had cake running on a Lantiq ADSL gateway running the same r46006
>>>>>>> build. Unfortunately this was bricked by attempts to get homenet
>>>>>>> working, so I have nothing to report about gateway usage at 
>>>>>>> present.
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> On 10/07/15 13:57, Jonathan Morton wrote:
>>>>>>>> You're already using correct syntax - I've written it to be quite
>>>>>>>> lenient and use sensible defaults for missing information. 
>>>>>>>> There are
>>>>>>>> several sets of keywords and parameters which are mutually 
>>>>>>>> orthogonal,
>>>>>>>> and don't depend on each other, so "besteffort" has nothing to 
>>>>>>>> do with
>>>>>>>> "overhead" or "atm".
>>>>>>>>
>>>>>>>> What's probably happening is that you're using a slightly old 
>>>>>>>> version
>>>>>>>> of the cake kernel module which lacks the overhead parameter 
>>>>>>>> entirely,
>>>>>>>> but a more up to date tc which does support it. We've seen this
>>>>>>>> combination crop up ourselves recently.
>>>>>>>>
>>>>>>>> - Jonathan Morton
>>>>>>>>
>>>>> _______________________________________________
>>>>> Cerowrt-devel mailing list
>>>>> Cerowrt-devel@lists.bufferbloat.net
>>>>> https://lists.bufferbloat.net/listinfo/cerowrt-devel
>
> _______________________________________________
> Cerowrt-devel mailing list
> Cerowrt-devel@lists.bufferbloat.net
> https://lists.bufferbloat.net/listinfo/cerowrt-devel