CoDel - How to use

bodosom

If you were to start increasing queue length in local shapers AND enabling CoDel you might derive some benefit. But the only reason you would derive benefit from CoDel is because you increased the queue length so just don't.

I didn't increase the queue length. Did something change it as a result using codel?
In any case under some load situations codel has improved my performance. Under others it doesn't but it doesn't seem to make things worse so it's a net win.

Spritzup

So I've read this thread, and given the suggestion in it a try. However, when I enable Codel, I seem to lose about 20% of download speed (100mbps down to 75-80)… though it does solve the buffer bloat problem.

Is this expected behaviour?

~Spritz

Nullity

@Spritzup:

So I've read this thread, and given the suggestion in it a try. However, when I enable Codel, I seem to lose about 20% of download speed (100mbps down to 75-80)… though it does solve the buffer bloat problem.

Is this expected behaviour?

~Spritz

It should be limited to whatever bitrate you set.

Spritzup

@Nullity:

It should be limited to whatever bitrate you set.

Thank you for the response Nullity, I appreciate it. I've read many posts over the last week or so from you and Harvy66.

So it appears then if I'm seeing a drop in throughput, something isn't configured correctly… though I'm at a loss as to what it could be. Assuming the kids go down easy tonight, I'll play with it further tonight.

~Spritz

Harvy66

What rate did you set on your LAN and WAN?

Spritzup

@Harvy66:

What rate did you set on your LAN and WAN?

105/9.5mbps… After multiple speedtests, as well as monitoring usenet downloads I get 117/11mbps.

Again, thank you.

~Spritz

Nullity

@Spritzup:

@Harvy66:

What rate did you set on your LAN and WAN?

105/9.5mbps… After multiple speedtests, as well as monitoring usenet downloads I get 117/11mbps.

Again, thank you.

~Spritz

Are you using CODELQ or HFSC/CBQ/FAIRQ with the "Codel Active Queue" toggle enabled?

Spritzup

I've tried a few different ways to be honest. I was hoping to figure it out before posting here with my tail between my legs.

But here is what I've tried (note that the rates I used were consistent) –>

1.
CODELQ - Only

2.
HFSC - Parent
CODELQ - Child

FAIRQ - Parent
CODELQ - Child

CBQ - Parent
CODELQ - Child

Now 1-4 gave me very similar results, with only slight fluctuations in the throughput (1-2mbps). When I tried putting in an artificially lowered rate, it honored it.

I also changed the advanced settings to enabling net.inet.tcp.inflight.enable=1 which seemed to help smooth out ping spikes, and I disabled Hardware TSO offload as per a link posted by Harvy (see I really did read and try and figure this out on my own!).

Lastly I ran the wizard using HFSC queue, and it seemed to work as expected (buffer bloat under control, correct rate). However, two things I discovered that makes this a less than ideal situation -->

1. I don't like having to use a full blow QoS implementation without knowing why the simpler one didn't work. Nor do I love the potential support overhead this introduces.
2. When I went into the individual queue's after running the wizard to enable Codel, I was unable to due to the fact that the bandwidth numbers were decimals. It wouldn't let me save unless I put whole #'s (wherever a % was). This is despite the fact that the wizard uses decimals... is this a bug?

Thanks!

~Spritz

PS - If something is unclear, or terminology is incorrect, I apologize. I'm at work and don't have access to my pfsense box currently, so I'm pulling all this from memory.

I also tried running the QoS wizard, and this seemed to work quite well. It honored my set rate, as well as keeping my buffer bloat under control... but I'm not keen on just using the wizard unless I know why the other options didn't work.

Hugovsky

Very interesting subjet indeed.

Just a quick question: why, when I try to use sysctl net.inet.tcp.inflight in the console, I get

sysctl: unknown oid 'net.inet.tcp.inflight': No such file or directory

shouldn't I see it there?

JasonJoel

So I get a lot of bufferbloat when DOWNLOADS saturate my link. Uploads don't seem to cause the bloat.

I have codelq, and only codelq, turned on my WAN and LAN connections. I have a 300/20 connection. for WAN speed I set 17 Mb, for the LAN connections I put 1Gb.

Is there anything that can really be done about the download bloat? My pfSense is also my central router with 3 VLANs, so I'm not sure I can do much on the LAN side as I don't want to ruin my inter-VLAN routing speeds.

Jason

Harvy66

Set your LAN to 280Mb and see how it goes.

Mael

I'm also trying to battle buffer bloat by implementing CoDel. While it works well to eliminate the bloat, it also drops my download speed by 100Mbps. Here are the details.

My link speed is 250/10

dslreports speed tests without any shaping applied show speeds of 250/11, but I usually get a D or F for buffer bloat.

When I activate CoDel on the LAN/WAN interfaces with bandwidth set to 9Mbps on the WAN and 230Mbps on the LAN, my buffer bloat grade goes to an A, but my download speed drops to 148Mbps. I've tried raising the LAN interface bandwidth up to 240 and 250Mbps but this doesn't increase the download speeds past 150Mbps.

Why is CoDel taking such a big bite out of my download bandwidth? Is there better way to eliminate buffer bloat without such a big impact to download speed?

Hardware: Netgate SG-8860
pfSense Version: 2.3.2-RELEASE-p1

Harvy66

Where are you setting "Codel"? Got a screenshot? Sorry to sound not trusting, but you'd be amazed what people claim they're doing when they're not.

Mael

I'd love it if this was just a case of user error. Here are the screen shots.

LAN.PNG_thumb

WAN.PNG_thumb

usulsuspct

@Mael:

I'm also trying to battle buffer bloat by implementing CoDel. While it works well to eliminate the bloat, it also drops my download speed by 100Mbps. Here are the details.

My link speed is 250/10

dslreports speed tests without any shaping applied show speeds of 250/11, but I usually get a D or F for buffer bloat.

When I activate CoDel on the LAN/WAN interfaces with bandwidth set to 9Mbps on the WAN and 230Mbps on the LAN, my buffer bloat grade goes to an A, but my download speed drops to 148Mbps. I've tried raising the LAN interface bandwidth up to 240 and 250Mbps but this doesn't increase the download speeds past 150Mbps.

Why is CoDel taking such a big bite out of my download bandwidth? Is there better way to eliminate buffer bloat without such a big impact to download speed?

Hardware: Netgate SG-8860
pfSense Version: 2.3.2-RELEASE-p1

I have noticed the same with my connection 60/5 (provisioned at 73 / 6.5) - without shaper enabled I bounce off the provisioned speeds but get horrible marks for buffer bloat. If I enable the shaper (w/codel) shaper set for 63/5.5 my speeds drop to ~45 / 5 with "A" for buffer bloat. I am just wondering if my ISP is flexing its buffers on me and pfsense has to scale back the speeds to deal?

Harvy66

Could be specific to the Codel shaper but not the Codel queue discipline. Try using FairQ shaper, create a single default queue and enable Codel on that queue.

moscato359

I had the same problem with sch_codelq, but sch_fairq with codel fixed it

d4ab9f

@moscato359:

I had the same problem with sch_codelq, but sch_fairq with codel fixed it

I have the same problem (500/30 without shaping goes to 250/20 with codel shapers set to 20 for wan and 480 for lan)
Tried fairq shaper with the same result.

What is sch_codelq and sch_fairq? Is this the same as codelq shaper and fairq shaper in the gui?