[SPLIT] TCP Congestion Control

Post new topic   Reply to topic    DD-WRT Forum Index -> Atheros WiSOC based Hardware
Goto page Previous  1, 2, 3  Next
Author Message
ho1Aetoo
DD-WRT Guru


Joined: 19 Feb 2019
Posts: 2927
Location: Germany

PostPosted: Wed Jun 29, 2022 7:31    Post subject: Reply with quote
I don't quite understand.
TCP congestion control works according to the end to end principle.

The server sends data and the client receives data and confirms this with an ACK or NOACK - then the server adjusts its sending behavior.

Therefore the congestion control on your devices has only influence on the own upload behavior.

The congestion control on the Internet server can not be changed Smile

A router in between does nothing at all, it only forwards the packets (layer 3).

Congestion control works on layer 7

The congestion control could still play a role if you use VPN on the router - but this is more theoretical nature - because VPN usually runs over UDP

In a normal network where the internet traffic is simply forwarded by the router the congestion control on the router does not play a role at all - there are only two endpoints (the internet server and your end device).
Sponsor
Alozaros
DD-WRT Guru


Joined: 16 Nov 2015
Posts: 6410
Location: UK, London, just across the river..

PostPosted: Wed Jun 29, 2022 9:02    Post subject: Reply with quote
-did you do the test i was talking about ?
-did you see any difference...? (i did)...
-are there lost/delyed packets when torrenting (DL).. not the upload im talking about...
-what happens when there are lost packets when torrenting?
-is there a lost packets when you download...any files form internet, especially large ones..?
-is there a lost packets when you browsing and load a heavy pages and so on...?
-what if the router has many clients and lots of traffic as well some tons of lost packets on heavy WAN load...which is the normal TCP/IP stuff...?

Does TCP congestion control plays a role there, lost/delayed packets...??

I do know how TCP congestion works..according to what i read from the link I posted or wikipedia article..is there anything more to be said here..

and yes VPN is mostly UDP, so no relation with TCP congestion rules..unless you use it via TCP...
Cool Cool Cool Cool

and yes TCP congestion on router level does change the server settings..in order to improve the connection flow

if this will continue...I have to pull the Joker card and split the thread... Laughing Laughing

_________________
Atheros
TP-Link WR740Nv1 ---DD-WRT 55179 WAP
TP-Link WR1043NDv2 -DD-WRT 55303 Gateway/DoT,Forced DNS,Ad-Block,Firewall,x4VLAN,VPN
TP-Link WR1043NDv2 -Gargoyle OS 1.15.x AP,DNS,QoS,Quotas
Qualcomm-Atheros
Netgear XR500 --DD-WRT 55460 Gateway/DoH,Forced DNS,AP Isolation,4VLAN,Ad-Block,Firewall,Vanilla
Netgear R7800 --DD-WRT 55460 Gateway/DoT,AD-Block,Forced DNS,AP&Net Isolation,x3VLAN,Firewall,Vanilla
Netgear R9000 --DD-WRT 55363 Gateway/DoT,AD-Block,AP Isolation,Firewall,Forced DNS,x2VLAN,Vanilla
Broadcom
Netgear R7000 --DD-WRT 55460 Gateway/SmartDNS/DoH,AD-Block,Firewall,Forced DNS,x3VLAN,VPN
NOT USING 5Ghz ANYWHERE
------------------------------------------------------
Stubby DNS over TLS I DNSCrypt v2 by mac913


Last edited by Alozaros on Wed Jun 29, 2022 11:32; edited 1 time in total
ho1Aetoo
DD-WRT Guru


Joined: 19 Feb 2019
Posts: 2927
Location: Germany

PostPosted: Wed Jun 29, 2022 9:17    Post subject: Reply with quote
Nope I have not tested because I have not understood it properly as I said.

If the torrent client runs on the router then it also uses the congestion control of the router for the upload.

If the torrent client is running on your PC then it uses your PC's congestion control for the upload.

In both cases it uses the congestion control of the internet server for the download.

How the congestion control works I already told you.

The server sends TCP data to the client and the client confirms the arrival with ACK (acknowledgment) or a faulty transmission with NOACK (
No Acknowledgement) or there is a timeout

Thereupon the server adjusts its sending behavior and sends slower if necessary.

You can also read everything on Wikipedia.
There is clearly explained that the TCP congestion control works according to the end-to-end principle.
And that the server/sender is ALWAYS responsible for the congestion control algorythms.

https://en.wikipedia.org/wiki/TCP_congestion_control

https://en.wikipedia.org/wiki/TCP_congestion_control#Algorithms

Quote:
Per the end-to-end principle, congestion control is largely a function of internet hosts, not the network itself. There are several variations and versions of the algorithm implemented in protocol stacks of operating systems of computers that connect to the Internet.
Alozaros
DD-WRT Guru


Joined: 16 Nov 2015
Posts: 6410
Location: UK, London, just across the river..

PostPosted: Wed Jun 29, 2022 10:59    Post subject: Reply with quote
ho1Aetoo so, you admit that TCP CC could be related with torrent and dl/up speeds and control (packet loss /delay), and that there is a difference upon using different TCP congestion c settings...
Than why is all that mocking about... Embarassed Cool Laughing
We both know what TCP congestion is for, we both know how it works..but you are mocking about, what i said and you didn't do the torrent test.. Embarassed Embarassed witch i used to express my experience and results... Cool Cool Rolling Eyes

so, do the test and come back if you have anything else to say to improve the talk on the subject... Razz Shocked

_________________
Atheros
TP-Link WR740Nv1 ---DD-WRT 55179 WAP
TP-Link WR1043NDv2 -DD-WRT 55303 Gateway/DoT,Forced DNS,Ad-Block,Firewall,x4VLAN,VPN
TP-Link WR1043NDv2 -Gargoyle OS 1.15.x AP,DNS,QoS,Quotas
Qualcomm-Atheros
Netgear XR500 --DD-WRT 55460 Gateway/DoH,Forced DNS,AP Isolation,4VLAN,Ad-Block,Firewall,Vanilla
Netgear R7800 --DD-WRT 55460 Gateway/DoT,AD-Block,Forced DNS,AP&Net Isolation,x3VLAN,Firewall,Vanilla
Netgear R9000 --DD-WRT 55363 Gateway/DoT,AD-Block,AP Isolation,Firewall,Forced DNS,x2VLAN,Vanilla
Broadcom
Netgear R7000 --DD-WRT 55460 Gateway/SmartDNS/DoH,AD-Block,Firewall,Forced DNS,x3VLAN,VPN
NOT USING 5Ghz ANYWHERE
------------------------------------------------------
Stubby DNS over TLS I DNSCrypt v2 by mac913
ho1Aetoo
DD-WRT Guru


Joined: 19 Feb 2019
Posts: 2927
Location: Germany

PostPosted: Wed Jun 29, 2022 15:48    Post subject: Reply with quote
I don't mock about it.
I was just explaining to you how TCP congestion control works.

And I still don't understand which scenario to test exactly.
You said something about "in both cases".

I can vividly assure you that TCP congestion control only works on the Server/sender side.

And when you download, you are the receiver, not the sender. Smile
So you can configure any congestion control you want on your router or PC - it won't affect your download at all.

But if you have a totally shitty asymmetric DLS line then we both know that the upload affects the download.
Since the uplink capacities are maxed out at times (1Mbit upload i in relation to 16 hehe) and can therefore also block the download, this has at most indirectly something to do with the TCP congestion control.
the-joker
DD-WRT Developer/Maintainer


Joined: 31 Jul 2021
Posts: 2146
Location: All over YOUR webs

PostPosted: Wed Jun 29, 2022 17:05    Post subject: Reply with quote
The thread has been split, applied congestion control on a re-transmission via sender thommy181 where clearly there is an open loop situation and now the choke packet has been sent.

So now we have a leaky bucket and flow can remain constant.

@thommy181 using a build thread to ask about ideal settings with ontopic info? I guess asking for forgiveness is better than asking for permission. Wink

_________________
Saving your retinas from the burn!🔥
DD-WRT Inspired themes for routers
DD-WRT Inspired themes for the phpBB Forum
DD-WRT Inspired themes for the SVN Trac & FTP site
Join in for a chat @ #style_it_themes_public:matrix.org or #style_it_themes:discord

DD-WRT UI Themes Bug Reporting and Discussion thread

Router: ANus RT-AC68U E1 (recognized as C1)
the-joker
DD-WRT Developer/Maintainer


Joined: 31 Jul 2021
Posts: 2146
Location: All over YOUR webs

PostPosted: Wed Jun 29, 2022 17:25    Post subject: Reply with quote
dplettner wrote:
thommy181 wrote:
I'm dont touch this better. On my device was 4096 always. I'm never touch this settings. It's puzzling why that big value is there as default.
I have never touched this either. On my Netgear R7800 it is set to 32768. Perhaps the firmware sets it based on the speed of the CPU?


Consider that torrenting is a very resource intensive process where encrypted torrents are concerned, so if you have push bike you may wanna lower the number to something manageable if there is any congestion happening, and picking an algorithm to manage the situation.

To be honest I think torrenting on any most consumer routers is insane, so expect everything to start going slower.

_________________
Saving your retinas from the burn!🔥
DD-WRT Inspired themes for routers
DD-WRT Inspired themes for the phpBB Forum
DD-WRT Inspired themes for the SVN Trac & FTP site
Join in for a chat @ #style_it_themes_public:matrix.org or #style_it_themes:discord

DD-WRT UI Themes Bug Reporting and Discussion thread

Router: ANus RT-AC68U E1 (recognized as C1)
Alozaros
DD-WRT Guru


Joined: 16 Nov 2015
Posts: 6410
Location: UK, London, just across the river..

PostPosted: Thu Jun 30, 2022 6:28    Post subject: Reply with quote
ho1Aetoo wrote:
I don't mock about it.
I was just explaining to you how TCP congestion control works.

And I still don't understand which scenario to test exactly.
You said something about "in both cases".

I can vividly assure you that TCP congestion control only works on the Server/sender side.

And when you download, you are the receiver, not the sender. Smile
So you can configure any congestion control you want on your router or PC - it won't affect your download at all.

But if you have a totally shitty asymmetric DLS line then we both know that the upload affects the download.
Since the uplink capacities are maxed out at times (1Mbit upload i in relation to 16 hehe) and can therefore also block the download, this has at most indirectly something to do with the TCP congestion control.


Yep you are correct on the system level OS is taking control of the congestion control......but on my Win 7 this is disabled...same for Win 10...or my Linux... Razz
and yes i do have ISP aggregated shitty line of 200Mbit local country peering + 60 Mbit worldwide internet...

_________________
Atheros
TP-Link WR740Nv1 ---DD-WRT 55179 WAP
TP-Link WR1043NDv2 -DD-WRT 55303 Gateway/DoT,Forced DNS,Ad-Block,Firewall,x4VLAN,VPN
TP-Link WR1043NDv2 -Gargoyle OS 1.15.x AP,DNS,QoS,Quotas
Qualcomm-Atheros
Netgear XR500 --DD-WRT 55460 Gateway/DoH,Forced DNS,AP Isolation,4VLAN,Ad-Block,Firewall,Vanilla
Netgear R7800 --DD-WRT 55460 Gateway/DoT,AD-Block,Forced DNS,AP&Net Isolation,x3VLAN,Firewall,Vanilla
Netgear R9000 --DD-WRT 55363 Gateway/DoT,AD-Block,AP Isolation,Firewall,Forced DNS,x2VLAN,Vanilla
Broadcom
Netgear R7000 --DD-WRT 55460 Gateway/SmartDNS/DoH,AD-Block,Firewall,Forced DNS,x3VLAN,VPN
NOT USING 5Ghz ANYWHERE
------------------------------------------------------
Stubby DNS over TLS I DNSCrypt v2 by mac913
ho1Aetoo
DD-WRT Guru


Joined: 19 Feb 2019
Posts: 2927
Location: Germany

PostPosted: Thu Jun 30, 2022 12:16    Post subject: Reply with quote
Just a quick comment again.
You cannot deactivate the TCP congestion control, neither under Windows nor under Linux.

If you set the congestion control to "none" (congestionprovider=none) under Windows 7 or 10, the built-in TCP congestion control is used, and this is NewReno for the Windows non-server versions.

Every computer has and needs its own TCP congestion control.
the-joker
DD-WRT Developer/Maintainer


Joined: 31 Jul 2021
Posts: 2146
Location: All over YOUR webs

PostPosted: Thu Jun 30, 2022 12:38    Post subject: Reply with quote
Windows 7 IDK what it uses. But doesn't windows 10 use CUBIC nowadays?
_________________
Saving your retinas from the burn!🔥
DD-WRT Inspired themes for routers
DD-WRT Inspired themes for the phpBB Forum
DD-WRT Inspired themes for the SVN Trac & FTP site
Join in for a chat @ #style_it_themes_public:matrix.org or #style_it_themes:discord

DD-WRT UI Themes Bug Reporting and Discussion thread

Router: ANus RT-AC68U E1 (recognized as C1)


Last edited by the-joker on Thu Jun 30, 2022 12:44; edited 1 time in total
ho1Aetoo
DD-WRT Guru


Joined: 19 Feb 2019
Posts: 2927
Location: Germany

PostPosted: Thu Jun 30, 2022 12:43    Post subject: Reply with quote
https://docs.microsoft.com/en-us/powershell/module/nettcpip/set-nettcpsetting?view=windowsserver2019-ps

Quote:
Default. Servers use DCTCP by default. Client computers use NewReno. For information about NewReno, see RFC


and cubic was only added later with a windows 10 creator update

https://homepages.rpi.edu/~wangy52/PersonalWebsite/build/html/Network/NetworkProgramming/CheckTCPCCVariation.html

assuming what it says is true
the-joker
DD-WRT Developer/Maintainer


Joined: 31 Jul 2021
Posts: 2146
Location: All over YOUR webs

PostPosted: Thu Jun 30, 2022 12:57    Post subject: Reply with quote
Which brings me to `IP Filter Settings (Adjust for P2P)` in DD-WRT that its not P2P only, Im not looking at source code, just purely from a labeling point of view, I dont think this label is remotely close to accurate.
_________________
Saving your retinas from the burn!🔥
DD-WRT Inspired themes for routers
DD-WRT Inspired themes for the phpBB Forum
DD-WRT Inspired themes for the SVN Trac & FTP site
Join in for a chat @ #style_it_themes_public:matrix.org or #style_it_themes:discord

DD-WRT UI Themes Bug Reporting and Discussion thread

Router: ANus RT-AC68U E1 (recognized as C1)
Alozaros
DD-WRT Guru


Joined: 16 Nov 2015
Posts: 6410
Location: UK, London, just across the river..

PostPosted: Thu Jun 30, 2022 14:20    Post subject: Reply with quote
yep linux is on Cubic by default and this is its native TCP CC

cat /proc/sys/net/ipv4/tcp_congestion_control
cubic

my Windows 7 ctcp is set to none...
and TCP CC is using the router side i believed.. Rolling Eyes
not much point/logic to set it to none and than to use the default one...isn't it ?

congestion provider - One of the following values:

none: Use the built-in standard congestion control algorithm.

ctcp: Use the add-on Compound TCP congestion control algorithm.

default: Restore the selected provider to the system default.

on Win 10 there is no ctcp config like in win 7, but because of the delivery guarantees of TCP there is no way to disable congestion control completely. win 10 "netsh int tcp set global congestionprovider=none"

On the router TCP CC serves its local congestion WAN to LAN or local clients.. services ("transmission") if you look at the torrents, they open a hole in local firewall Win firewall(specific port) and on the router side as those related, established connections are permited...and then connection is direct, so i had a believe those use the router TCP CC and therefore i could see the difference between using Vegas, BBR, Cubic or Westwood or others...
So far my best results ware Vegas, Cubic/BBR where there is BBRv2 nowadays..that I've not seen around or tested...
At the end of the day i may had a glitch from a high proton beam...as a results...or whatever... Rolling Eyes Laughing

_________________
Atheros
TP-Link WR740Nv1 ---DD-WRT 55179 WAP
TP-Link WR1043NDv2 -DD-WRT 55303 Gateway/DoT,Forced DNS,Ad-Block,Firewall,x4VLAN,VPN
TP-Link WR1043NDv2 -Gargoyle OS 1.15.x AP,DNS,QoS,Quotas
Qualcomm-Atheros
Netgear XR500 --DD-WRT 55460 Gateway/DoH,Forced DNS,AP Isolation,4VLAN,Ad-Block,Firewall,Vanilla
Netgear R7800 --DD-WRT 55460 Gateway/DoT,AD-Block,Forced DNS,AP&Net Isolation,x3VLAN,Firewall,Vanilla
Netgear R9000 --DD-WRT 55363 Gateway/DoT,AD-Block,AP Isolation,Firewall,Forced DNS,x2VLAN,Vanilla
Broadcom
Netgear R7000 --DD-WRT 55460 Gateway/SmartDNS/DoH,AD-Block,Firewall,Forced DNS,x3VLAN,VPN
NOT USING 5Ghz ANYWHERE
------------------------------------------------------
Stubby DNS over TLS I DNSCrypt v2 by mac913


Last edited by Alozaros on Thu Jun 30, 2022 14:40; edited 1 time in total
mrjcd
DD-WRT Guru


Joined: 31 Jan 2015
Posts: 6268
Location: Texas

PostPosted: Thu Jun 30, 2022 14:36    Post subject: Reply with quote
mine Twisted Evil
https://mrjcd.com/junk/dd-wrt/TCP_congestion_control.html
the-joker
DD-WRT Developer/Maintainer


Joined: 31 Jul 2021
Posts: 2146
Location: All over YOUR webs

PostPosted: Thu Jun 30, 2022 15:27    Post subject: Reply with quote
@alozaros, Microsoft's logic is beyond reproach Wink, to be fair you have to have some type of CC and they assume most ppl just plug the WAN cable to the back of the machine and back then (Windows Vista/7) they weren't far from the truth and still in many parts of the world they are close to it.

And I'm still trying to find out if DD-WRT's CC is up for all outgoing traffic or just p2p without doing much work, yep Im also lazy, deal with it.

_________________
Saving your retinas from the burn!🔥
DD-WRT Inspired themes for routers
DD-WRT Inspired themes for the phpBB Forum
DD-WRT Inspired themes for the SVN Trac & FTP site
Join in for a chat @ #style_it_themes_public:matrix.org or #style_it_themes:discord

DD-WRT UI Themes Bug Reporting and Discussion thread

Router: ANus RT-AC68U E1 (recognized as C1)


Last edited by the-joker on Thu Jun 30, 2022 15:31; edited 1 time in total
Goto page Previous  1, 2, 3  Next Display posts from previous:    Page 2 of 3
Post new topic   Reply to topic    DD-WRT Forum Index -> Atheros WiSOC based Hardware 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 cannot attach files in this forum
You cannot download files in this forum