Noob needing help with SQM TP-Link Archer C7 AC1750

Installing and Using OpenWrt
1

Hello, I had a problem with gaming when my family were watching Netflix and what not as my ping would be unplayable. I found out about bufferbloat and SQM basically a week ago, bought a new router in Archer C7, installed openwrt and configured SQM.

Although it did eliminate alot of my bufferbloat and I get a grade of A on dslreports, compared to B from before, I still experience ping spikes once at least every 30 seconds. Also, when I click a Netflix show, ping would spike to around 100 for a second, which is not good for my gaming experience.

I'm based in Australia and use "Hybrid Fibre Coaxial" for my internet supply, with max speed of 50mbps and around 10-15 upload. Wireless download speed to my room is around 30mbps. I've tried configuring bandwidth from 40000 to 10000 and doesn't seem to make much of a difference. Thing is, when I connect on ethernet, there would be no ping spike when I load a netflix show. I'm extremely frustrated and would extremely appreciate any help as I am a total newbie in this world. I'll provide more info if required.

cat /etc/config/sqm

config queue
        option interface 'eth0.2'
        option debug_logging '0'
        option verbosity '5'
        option qdisc 'cake'
        option qdisc_advanced '1'
        option upload '0'
        option enabled '1'
        option linklayer 'ethernet'
        option squash_dscp '1'
        option squash_ingress '1'
        option ingress_ecn 'ECN'
        option egress_ecn 'NOECN'
        option download '10000'
        option script 'piece_of_cake.qos'
        option overhead '44'
2

if there's no spike using an ethernet cable, would indicate a wifi issue, not SQM ?

1 Like
3

Periodic latency excursions on WiFi can well be caused by a number of processes like:
a) periodic channel scans, where your router or your station checks other channels to maintain an overview of which APs/station show up on which frequencies
b) powersaving features that might kick-in, say because gaming traffic is sparse enough
c) external interference sources that affect the WiFi SNR, like an AP/station from a neighbor that can't see your AP but sends at the same frequency
d) some other source of cyclic RF interference...

In short that is a bit rough...

To help a bit with your gaming, you might want to switch to cake's per-internal-IP-fairness modes by adding

        option itarget 'auto'                                                                                                                                                                   
        option etarget 'auto'                                                                                                                                                                   
        option qdisc 'cake'                                                                                                                                                                     
        option script 'layer_cake.qos'                                                                                                                                                          
        option qdisc_advanced '1'                                                                                                                                                               
        option squash_dscp '0'                                                                                                                                                                  
        option squash_ingress '0'                                                                                                                                                               
        option qdisc_really_really_advanced '1'                                                                                                                                                 
        option eqdisc_opts 'nat dual-srchost'                                                                                                                                                   
        option linklayer 'ethernet'                                                                                                                                                             
        option linklayer_advanced '1'                                                                                                                                                           
        option tcMTU '2047'                                                                                                                                                                     
        option tcTSIZE '128'                                                                                                                                                                    
        option linklayer_adaptation_mechanism 'default'                                                                                                                                         
        option iqdisc_opts 'nat dual-dsthost ingress'                                                                                                                                           
        option tcMPU '64'                                                                                                                                                                       
        option download '40000'
        option upload '10000'

So the first goal is to debloat your internet access link, and then we can look at how to fix your WiFi, but let's do this in two steps as otherwise it gets hard to figure out what does and what does not help.

Ideally you would post the results to speedtests without SQM and with SQM enabled taken from a device connected to the router with a real ethernet cable.