@Voxel Firmware for R9000 ---> Kernel 4.15?

[multicast]

Hi Voxel

Is there any possibility to have BBR Congestion Protocol running in your firmware?

Thanks in advance for such amazing effort you put in this magnificent FW.

 

[microchip]

Not a chance. Voxel does not do kernel backporting. Besides, it has been found that BBR can be highly unfair despite what Google may claim https://en.wikipedia.org/wiki/TCP_congestion_control#TCP_BBR

I suggest you use YeAH or Westwood as CC. YeAH is highly fair at the cost of slighly lower throughput. Westwood can be very greedy but performs extremely well in wireless networks with a lot of packet loss

 

[multicast]

Thank for the feedback and very interesting info!
Quick question, based on your knowledge and experience, what would the best CC for a Giga internet connection?
will the CC affects the internet throughput in my LAN when using a router with NAT?

Thanks in advance @microchip

 

[microchip]

I personally use YeAH on all my PCs/router for my 1 Gbps connection. I was previously using Westwood but found out that it chokes other connections while downloading a torrent at max speed, i.e. other connections become a bit slower (stuff like regular browsing). I do not have the same issue with YeAH.

From what I've read in different academic papers, Westwood can be very greedy and as I mentioned excelles at WiFi networks with (lots of) packet loss. I personally prefer a CC that is very fair so my resources get as equal as possible distribution under congestion pressure if it happens

CC has a minor impact on LAN traffic. You will rarely hit congestion unless you max out your connection using multiple devices at the same time

 

[multicast]

Thank you again @microchip , I've switched to it, I'll test it, I noticed same thing with Westwood. Cubic seems to be working better but might be just my impression.

Have you changed your CC values? I did tweak the from what Voxel's firmware had by default.

One last question, will this CC help to get better internet throughput Orit will just affect servers throughput running in the router itself?

 

[microchip]

I use default CC and network values, only switched from Westwood to YeAH.

YeAH is advertised as a sender-side only modification of TCP Vegas and NewReno, although it appears it has effect on downloading as well based on personal experience. If you only use YeAH on the router itself, it will do its best to fairly manage all outgoing throughput (not just stuff running on the router but also outgoing data). As I mentioned, with YeAH you're trading a bit of throughput for high fairness for all outgoing connections from the router. YeAH is a hybrid CC (packet loss & delay based) while Westwood is only packet-based with bandwidth estimation. That last one appears to work well (maybe even too well?) and I suspect that is the reason for the greedy behavior of Westwood. It will squeeze out every possible throughput you have when you push it to your limits.

In practice, I suggest you do some testing yourself and pick one that works well for you. There are trade-offs in every available CC algo in Linux.

 

[multicast]

Thank you @microchip

 

[multicast]

@microchip check this out


I did test with these parameters, it seems YeHA takes the lead for 2Mbps over Cubic.

Westwood

YeHA

Cubic

Vegas

 

[microchip]

you should retest multiple times (like 5 or so) for each CCA and then plot an average for each. Then you'll have pretty good idea of what to choose

When chosing a CCA, you most likely want one that does not tend to choke all other connections when one of them tries to claim all available bandwidth. If this means that you may get a slightly lower throughput but decent amount of fairness, like in the case of YeAH, and you can live with that (as I can), then choose that. If you have other priorities, choose something else more suited. Also, it is important that the chosen CCA is fair against not only itself (where TCP Illinois fails even that) but also is fair against other CCAs, including Compound TCP if you're on Windows

 

[multicast]

Gonna follow your advice about the testing and get an average, thanks again for all the info and help on this matter!