Traffic Shaping - What is and how to use (non-main router)?

Post new topic   Reply to topic    DD-WRT Forum Index -> General Questions
Author Message
Fried Chicken
DD-WRT User


Joined: 12 Jun 2019
Posts: 186
Location: Texas

PostPosted: Thu Aug 29, 2024 20:57    Post subject: Traffic Shaping - What is and how to use (non-main router)? Reply with quote
Could someone provide clarity for the best practices for traffic shaping/management/bufferbloat reduction or whatever the formal name is for secondary network devices (not the main router)?

SQM, SFE, QoS, CTF, etc.

I have a main router running DD-WRT with SFE enabled. This is the topic of the majority of threads, but what about all the other devices? I have additionally another router (R7000p) running DD-WRT as a router and DHCP forwarder and access point. I have a smattering of access points throughout as well.

All of these devices offer some sort of traffic shaping. On the R7000p I have options for SFE, CTF, and QoS. On the other access points (Cisco) there are also QoS Settings.

Windows itself has options for QoS in its adapter settings (ethernet, wifi, etc.).



From my experience and testing, it's a rather processor intensive process, and will limit bandwidth if whatever is doing the traffic shaping is not up to the task. But beyond that I do not understand how it's implemented. Is it only for sent data, or also sent/received data?

Is it best to have it only enabled on the main router, and then the beautifully shaped traffic can get distributed to/from all the secondary devices...

or should the secondary devices also do traffic shaping for their system? Or does it only go in one direction for endpoint devices, so i.e. on Windows, QoS will shape the traffic going out.

How would the different ways of traffic shaping interact with one another?

It makes no sense to me, and I'd like some insight on how/what to do.

_________________
Google is Spyware
Sponsor
feliciano
DD-WRT Guru


Joined: 24 Oct 2008
Posts: 1094
Location: Latin America

PostPosted: Sat Aug 31, 2024 15:35    Post subject: How QoS works Reply with quote
Strictly speaking, you cannot directly throttle down the downlink traffic. BUT you can measure it, classify it, and knowing that a window of packets it's send down to you after you request it, you can decide which kind of traffic request more or less of, therefore indirectly controlling and shaping the DL bandwith to your preference. That's the general idea. Different algorithms/methods do it in different ways. You could study each one in detail, and/or apply trial and error.

For sure that would imply more CPU/memory consumption, and probably one type of traffic (like speedtest) will not top the available BW, because you will reserve some for other tasks, but for some scenarios people consider it worthy. For those reasons, that kind of configuration is optional.

_________________
If you want support, please read first the announcements and forum rules.
Si usted desea ayuda, por favor lea primero los anuncios y las reglas del foro.
Fried Chicken
DD-WRT User


Joined: 12 Jun 2019
Posts: 186
Location: Texas

PostPosted: Mon Sep 02, 2024 6:01    Post subject: Re: How QoS works Reply with quote
feliciano wrote:
Strictly speaking, you cannot directly throttle down the downlink traffic. BUT you can measure it, classify it, and knowing that a window of packets it's send down to you after you request it, you can decide which kind of traffic request more or less of, therefore indirectly controlling and shaping the DL bandwith to your preference. That's the general idea. Different algorithms/methods do it in different ways. You could study each one in detail, and/or apply trial and error.

For sure that would imply more CPU/memory consumption, and probably one type of traffic (like speedtest) will not top the available BW, because you will reserve some for other tasks, but for some scenarios people consider it worthy. For those reasons, that kind of configuration is optional.


I've already done all the trial and error I could and basically settled on SFE for my x86 router.

I seek to understand the traffic shaping of devices downstream of the router: Access points, Switches, and end user's computers.

All of my access points (Cisco) let me configure QoS on their end and one of them lectures me that I should. Windows has QoS settings in its networking settings. My understanding is this allows lower latency under load, a valiant effort as right now I get very high latency under load over wifi.

What I want to know: how does all of this work, and how does all of this interact?

_________________
Google is Spyware
feliciano
DD-WRT Guru


Joined: 24 Oct 2008
Posts: 1094
Location: Latin America

PostPosted: Wed Sep 11, 2024 23:07    Post subject: Reply with quote
It's the same,

Let's say you're a traffic controller and you have 10 runways for up to 10 aircrafts to land simultaneously, to then be routed to the particular taxi ways (your downstream routers, PC, smartphone, etc.). With your radio you take the power to tell "you go first", "you wait", and so on. If you're at the busy hour, you can remove latency to the one you want by clearing it and not authoring the others yet. If you're at the valley hour you just authorize whatever request coming from your downstream clients. I think you can picture the overall procedure.

_________________
If you want support, please read first the announcements and forum rules.
Si usted desea ayuda, por favor lea primero los anuncios y las reglas del foro.
Display posts from previous:    Page 1 of 1
Post new topic   Reply to topic    DD-WRT Forum Index -> General Questions All times are GMT

Navigation

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You can attach files in this forum
You can download files in this forum