Cake settings for only upload speed

[erhtun]

Hi, I want to use Qos Cake on RT-AX68U. I have cable internet based on DOCSIS. So I have set WAN overhead to 18 MPU: 64 and Mode: Normal. My internet plan is 100 Mbps download, 5 Mbps upload plan. But downlink rate decrease to 25 Mbps for 19:00 - 00:00. So I have set bandwidth to Automatic. If I set only 5Mbps for upload and leave 0 to download speed, does Cake QoS run properly.

 

[Lynx]

Setting the CAKE bandwidth to 0Mbit/s for download will effectively disable it for download. Setting 5Mbit/s for upload will handle your upload-related bufferbloat, but your download-related bufferbloat will not be addressed. To deal with your varying download link capacity, you would need to dynamically adjust the CAKE bandwidth.

As a first option, you could use my script here:

GitHub - lynxthecat/cake-autorate: Eliminate the excess latency and jitter terrorizing your 4G, 5G, LTE, Starlink or other variable rate connection!

Eliminate the excess latency and jitter terrorizing your 4G, 5G, LTE, Starlink or other variable rate connection! - lynxthecat/cake-autorate

github.com

This has been tested by a fair number of OpenWrt users now with different types of connections such as LTE, Starlink and DOCSIS, and it generally works well.

I am pretty sure it could be made to work in Asus Merlin. It is just a bash script that uses 'iputils-ping' and makes appropriate 'tc qdisc change' calls.

@dave14305 am I right that this script would pretty much work as is in Asus Merlin? Are 'bash' and 'iputils-ping' available?

As a second option, if if your download bandwidth is stable at the 100Mbit/s and at 25Mbit/s settings according to your plan, then you could rather more simply just set up cron jobs to set the appropriate bandwidths at the appropriate times, i.e. drop down to 25Mbit/s between 19:00 to 00:00 and otherwise set it back up to 100Mbit/s outside these hours.

The second option would be optimal if indeed the bandwidth is stable at these two levels - automatic adjustment of bandwidth based on RTT measurements necessarily requires letting through some bufferbloat as part of tracking the varying line capacity (albeit happily for many including myself this is sufficiently minor that it does not interfere with videoconferencing).

 

[erhtun]

First of all thank you to this detailed answer. My download bandwidth is stable so I want to set up cron jobs to set 25 Mbit/s at 19:00 and 100 Mbit/s at 00:00. But I don't know how to do it?

 

[Lynx]

https://github.com/RMerl/asuswrt-merlin.ng/wiki/Scheduled-tasks-(cron-jobs)

https://www.cyberciti.biz/faq/how-to-add-cron-job-on-asuswrt-merlin-wifi-router/

 

[erhtun]

As far as I understand, I can set the cron job like below;

cru a downlinkTo25 0 19 * * * {command to set Qos Download Bandwidt to 25 Mbit/s}

cru a downlinkTo100 0 0 * * * {command to set Qos Download Bandwidt to 100 Mbit/s}

Which command should I use to set download bandwith?

 

[dave14305]

Which command should I use to set download bandwith?

nvram set qos_ibw=100000
nvram commit
service "restart_qos;restart_firewall"

 

[Lynx]

nvram set qos_ibw=100000 nvram commit service "restart_qos;restart_firewall"

Why not just:

tc qdisc change root dev $interface cake bandwidth ${shaper_rate_kbps}Kbit

I suppose the latter won't update the GUI?