FYI/A: Bufferbloat 101

[hwzlite]

Latest Update On 04/2024 :

The go-to-de-facto Web-based Tests now is https://www.waveform.com/tools/bufferbloat

As it was reported that https://www.dslreports.com/speedtest somehow time to time broken in one way or another...

Good video info here for people who are new to bufferbloat ( thx to bro @xiaofan for the head-out ) :




A picture speaks a thousand words:

• What Can I Do About Bufferbloat?
• Tests for Bufferbloat
• Example1 , Example2 on Client-based Tests tool Crusader , available in linux , android , windows
• Example on Client-based Tests tool Flent RRUL , available in linux, FreeBSD, macOS
• Example1 & Example2 on Wireless WiFi Test using TXQS/ATF/AQL supported mac80211 linux driver

XXXXXXXXXXXXXXXXXXXXX Original old reference info below Last edited on Dec 18, 2000 XXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX

• Classic Video demoing speaks for itself @ 3:08mins
  [*]"Your ISP would love to sell you a faster connection, but link speed isn’t the problem - it’s your router buffering more data than necessary"
  [*]"Bufferbloat is a common problem. It is not something your ISP is going to solve for you."
• 2020: Bufferbloat may be solved, but it’s not over yet

Here was my test result (M1 500mbps fiber cheapo plan) , tamed under DD-WRT (D-Link DIR-868L) router.

HSFC+CAKE SQM :
http://www.dslreports.com/speedtest/66614028 -



Optimized pure CAKE mode which by design works best without any rate limiters sure as HTB/HFSC scheduler.
(For some strange reason, the developer of DD-WRT did not make a standalone Option for CAKE , so have to tweak it via CLI ) .
http://www.dslreports.com/speedtest/66656741 -

FYI: Consolidated SG ISPs speed test results:

• AS9506 - Singtel Fibre Broadband
• AS4773 - MobileOne
• AS18106 - Viewqwest
• AS56300 - MyRepublic
• AS55430 - Starhub

Examples: Results from those untamed top-tier 1GB plan, upload bufferload (lag) under load can reach as high ~900ms :
M1 http://www.dslreports.com/speedtest/66518951
Singtel http://www.dslreports.com/speedtest/66598644
Starhub http://www.dslreports.com/speedtest/66471859


http://www.dslreports.com/speedtest



.

 

[uncle_josh]

Explaining And Fixing Bufferbloat
Bufferbloat is high latency (or lag) that occurs when there’s other traffic on your network.

What’s wrong with simply configuring QoS?
Quality of Service (QoS) settings will help, but won’t solve bufferbloat completely. Why not? Any prioritization scheme works by pushing certain packets to the head of the queue, so they’re transmitted first. Packets farther back in the queue still must be sent eventually. New traffic that hasn’t been prioritized gets added to the end of the queue, and waits behind those previously queued packets. QoS settings don’t have any way to inform the big senders that they’re sending too fast/too much, so packets from those flows simply accumulate, increasing delay for all.

Why does SQM work so well ?
These smart queue management (SQM) algorithms put each flow’s traffic into its own queue. (A “flow” is typically defined as traffic from a single IP addresses/port to another address/port.) Then the qdisc makes sure that none of the queues get “too long”

For more information : More about Bufferbloat

 

[xiaofan]

Tested with my Huawei P20 mobile phone on WiFi, SingTel 1Gbps Fibre, Asus RT-AX82U router

http://www.dslreports.com/speedtest/66622024

Edit to add: this result is not correct as I wrongly select "Public WiFi" for the test. Real results are worse.

 

[xiaofan]

FYI: Consolidated SG ISPs speed test results:

• AS9506 - Singtel Fibre Broadband
  
• AS4773 - MobileOne
  
• AS18106 - Viewqwest
  
• AS56300 - MyRepublic
  
• AS55430 - Starhub

http://www.dslreports.com/speedtest

Of the big three, M1 > Starhub > SingTel. This is probably due to the fact that default M1 router is better and default SingTel router is lousy (especially AC Plus and AC Elite which were given in the past few years). M1 latency is also usually better than SingTel. Starhub is usually in between SingTel and M1.

 

[xiaofan]

I tend to believe many users use WiFi client (lower bandwidth) to test. If using wired client, probably the issue will be less severe as majority of the local users are on 500Mbps or faster connections.

But if using wifi, users using poor wifi routers/AP like the SingTel AC Plus will often have low speed connection and then bufferbloat issues may present more obviously.

 

[TanKianW]

 

[uncle_josh]

 

[-Grift-]

M1

 

[miloaisdino]

singtels bufferbloat is quite bad imo. when the line is saturated the ping can spike to few hundred ms. will publish the results later. and during certain times of the day, testing is inaccurate since the dslreports server is softlayer sg, which singtel has poor routes to.

 

[-Grift-]

singtels bufferbloat is quite bad imo. when the line is saturated the ping can spike to few hundred ms. will publish the results later. and during certain times of the day, testing is inaccurate since the dslreports server is softlayer sg, which singtel has poor routes to.

Quite sure your router plays a bigger part

 

[miloaisdino]

Quite sure your router plays a bigger part

i tested by directly connecting to ont...

 

[uncle_josh]

Get a better router that could better do a smart queue management (SQM)

 

[Qubicfactor]

on wireless, with a pair of Asus routers.

 

[miloaisdino]

on wireless, with a pair of Asus routers.

what ont are you on? im on zte

Get a better router that could better do a smart queue management (SQM)

thats a stopgap measure. anyone can do that with any isp.

 

[Qubicfactor]

what ont are you on? im on zte

The old white Ericsson

 

[miloaisdino]

The old white Ericsson

maybe thats why
zte from china sucks.

 

[Qubicfactor]

maybe thats why
zte from china sucks.

I have a feeling it's partially because you connected straight to the ONT though, so no router to help manage the bufferbloat, even though there is also no router to mismanage it.

 

[xiaofan]

Tested with my Huawei P20 mobile phone on WiFi, SingTel 1Gbps Fibre, Asus RT-AX82U router

http://www.dslreports.com/speedtest/66622024

I think I selected wrongly "Public WiFi" for the test.

Now I test again by the correct "Fibre" selection and the result is bad.
Mac Mini M1 on WiFi (2*2 AX), Chrome browser, Singtel 1Gbps Fibre, Asus RT-AX82U.

Bufferbloat is "D" or "C" even though Quality is A+.
http://www.dslreports.com/speedtest/66626339
http://www.dslreports.com/speedtest/66626339.png

 

[xiaofan]

maybe thats why
zte from china sucks.

Interesting. So you think the ONT plays a part. I am also using the ZTE ONT. I replaced my old Ericsson ONT back in Sept 2018 because of bad power contact (using it from the beginning of my sign up in Feb 2012).

 

[Mach3.2]

Wired ethernet connection to switch, then to my pfsense router.
Custom settings, 32 streams up and down. I checked the logs and only 8 streams are downloading for the download test though..