[SQM/QOS] Recommended settings for the dslreports speedtest (bufferbloat testing)

That sounds interesting, could you post a link to the detailed result of your speedtest, please (instructions in post #1 above). In theory that setting should give maximum bandwidth but should also show high latency-under-load numbers (bufferbloat); if it does not show bad bufferbloat, either your ISP runs a tight ship with little bufferbloat, or something is wrong. In any case I would recommend we discuss this in a different thread, as it seems only remotely related to settings for the dsreports speedtest, okay?

Best Regards

Hi,

After read topic and re-configure my test.

I run the tests with the default settings and get an "A" 99% of the time.

I believe that the fault of the low note, be it from my ISP, because although I use fiber I noticed that my line has a lot of packet loss, I would very much like to find a solution to stabilize the IPTV application quality in Smartv, I have not got it right yet.

continue to test the QOS settings until you find the best one

I am not quite sure what your exact problem is. In any way I believe that it is not directly related how to configure the dslreports speedtest and hence might be better placed in its own new thread.

Imho there should be a thread about the best SQM and overhead settings for diffrent types of access. (DSL/VDSL,CABLE/DOCSIS, Fiber aso)
It's quite hard to figure it out on your own if your not an expert about SQM QoS and i think that would help a lot of people not to wrongly configure SQM and get bad or even worse results that without SQM... :wink:

What you describe is exactly why CAKE was developed!

There isn't any "generic" settings possible as every line is different, even within the same technology and provider. It even varies by time of day, weather, and how long your modem has "trained" (sometimes over days).

Other challenges come with type of equipment. If you've got a DOCSIS 3.1 modem and a properly configured DOCSIS 3.1 head end, there's already PIE at the head end. Your settings may well be completely different than someone that has a DOCSIS 3.0 modem that gets routed to head-end equipment that doesn't supply PIE.

There might be some rules of thumb, but it really comes down to "try it and see", as well as your own tolerance for lag and how you balance that out against bandwidth.

Using flent-gui I can get a line "tuned" with CAKE or fq_codel to something reasonable in under an hour, without knowing what is happening in the algorithms.

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This is my current SQM settings, from another post on the forum:

sqm.eth1=queue
sqm.eth1.interface='pppoe-wan’
sqm.eth1.download='14400’
sqm.eth1.upload='10800’
sqm.eth1.debug_logging='0’
sqm.eth1.verbosity='5’
sqm.eth1.qdisc='cake’
sqm.eth1.script='piece_of_cake.qos’
sqm.eth1.qdisc_advanced='1’
sqm.eth1.squash_dscp='1’
sqm.eth1.squash_ingress='1’
sqm.eth1.ingress_ecn='ECN’
sqm.eth1.egress_ecn='ECN’
sqm.eth1.enabled='1’
sqm.eth1.qdisc_really_really_advanced='1’
sqm.eth1.itarget=‘7.5ms’ 
sqm.eth1.etarget=‘7.5ms’ 
sqm.eth1.iqdisc_opts='rtt 150ms nat dual-dsthost mpu 64’
sqm.eth1.eqdisc_opts=‘rtt 150ms nat dual-srchost mpu 64’
sqm.eth1.linklayer='ethernet’
sqm.eth1.overhead='8’
sqm.eth1.linklayer_advanced='1’
sqm.eth1.tcMTU='2047’
sqm.eth1.tcTSIZE='128’
sqm.eth1.tcMPU='128’
sqm.eth1.linklayer_adaptation_mechanism='cake’

So, I agree with your observation that this would be nice. But I also agree with @jeff that there typically is no generic setting that is easy to recommend.

Now two more procedural points:
a) Why don't you just start that thread? I believe you should have the permission to just start a new thread (and you could just start by moving your initial post into the new thread)

b) I would like to point out politely (and I know that this will partly fail) that this thread is not the right place to discuss per packet overhead or typical encapsulation schemes.

c) this is also not the best place to discuss individual /etc/config/sqm instances.

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Yes you are right about this thread, but i'm realy no expert about QoS.
But anyway i'm thinking about to start a new and clean thread about SQM QoS Settings.
Imho it's way better to have a general settings thread than searching through all the other question ones here in the forum !
Especially overhead calculation would be interesting... If you could offer some input out of your experience it could be a useful thread ! :slight_smile:

For example i never heared of "rtt 150ms and sqm.eth1.itarget=‘7.5ms’
sqm.eth1.etarget=‘7.5ms’ " settings before...
We can discuss this within the new thread, as you said it's not the right thread here and i completely understand this.

Thanks for your time.

2 Likes

For a start, use the LEDE luci-sqm interface to get a basic configuration without having to learn much... then learn more and experiment more. Start a thread if you need to.

And yes, this isn't the place, just the place holder of the "standardized" settings for Dslreports, so we can have more consistent results using it as a testing tool.

Could you - perhaps on another thread - perhaps outline your procedure for tuning with flent in another thread?

1 Like

sorry if this is too old to reply... im having the same results. I get C in bufferbloat with or without SQM enabled. then if I try 0 ingress and ~100% egress, I can finally get an A.

Mmmh, how about we move this to a new topic, instead of tacking this discussion to the end of an only mildly related thread? Also, I will be on and off over the next two weeks, so I can not guarantee timely responses ...

Hi guys,

Great job, many thanks to all involved. My speed tests if of interest:

  1. new router, no sqm, old router (dedicated QoS to cable interconnection) between it and ISP, official ISP tariff 50 Mbits/s
    http://www.dslreports.com/speedtest/64231154

  2. no sqm, direct cable connection to ISP:
    http://www.dslreports.com/speedtest/64231576

now I have to figure out which interface to choose for the sqm (wan/wan6)
3. sqm, direct to ISP:

  1. sqm, through old router:
    http://www.dslreports.com/speedtest/64232060

4(b) sqm, old router (qos disabled):

Interesting results, clearly the router buffering a lot, will play around with sqm settings and old router.

All the best to everyone, take care in these difficult times.

Mike

Before:

After:

After (further tweaking):

I have a Linksys EA7500 V2 router and Hitron EN2251 modem (Intel Puma 7 chipset). Couldn't get any other free modem from Spectrum, unfortunately.

Unmitigated:

Mitigated: