RT-N66U bufferbloat

[pgershon]

I just upgraded my FIOS from 75/75 to 150/150. Some web sites seem to have a delay opening, or even require me to refresh the browser to open them (not address specific, i don't think). I did the dslreports speed test and it shows that while I achieve the promised 150/150, I have a "C" for bufferboat. I suspect that may be impacting my performance, and I also suspect that some tuning of the ASUS router is the best fix. Any thoughts on best way to do this?

 

[RMerlin]

Buffer bloat should only have an impact if you have a lot of concurrent connections.

Trouble loading certain sites can be caused by related to DNS or MTU issues.

(Personally, I think that the whole Buffer bloat issues are being "Buffer Overblown", but that's just my opinion...)

 

[Deleted member 22229]

Agree with Merlin buffer bloat is only a issue when your connection is being maxed out. Loading web sites would hardly even come close to maxing out your connection unless your speeds were like dial up.

 

[pgershon]

Thanks. So you would suggest I ignore the bufferbloat score of C and look for another cause? I tried connecting just one computer (iMac 2011) to router to ONT (took everything else off network) and bufferbloat score the same C.

 

[RMerlin]

Thanks. So you would suggest I ignore the bufferbloat score of C and look for another cause? I tried connecting just one computer (iMac 2011) to router to ONT (took everything else off network) and bufferbloat score the same C.

Yes, ignore the buffer bloat report for now. That only comes into play if you deal with time-sensitive applications like VoIP or online gaming WHILE your connection is saturated.

Some ISPs will require that you clone their MAC address to work properly. That might be worth a try (under WAN on your router).

Make sure your router uses your ISP's DNS, and that your computer uses the router's IP for its DNS (it will act as a caching server).

Also try replacing the Ethernet cable between the ONT and the router.

 

[Deleted member 22229]

Yes I would look for another cause when I take that test I get an F for buffer bloat but have no issues with my internet what so ever. Also doing some further testing I have discovered that my buffer bloat is not even being caused by the router I get the same F score directly connected to my modem with no router in the mix so at least for me buffer bloat is at the ISP level so there in nothing that can be done to correct it. Comcast says buffer bloat should no longer be an issues once Docsis 3.1 is deployed sometime next year.

 

[Nullity]

Bufferbloat is probably not the cause for your particular problems though. I would suspect DNS problems first. As Merlin suggests, bufferbloat is primarily a noticeable problem with VOIP or gaming, though it really depends on your gateway and/or ISP. Some can experience 2000ms+ of bufferbloat, which is pretty damn noticeable with any service.

The simplest way to fix bufferbloat is to use a gateway router that supports CoDel (and/or the soon to be finalized "cake") like IPFire or pfSense. My worst-case (saturated upload) latency went from 600ms to 50ms with CoDel (pfSense).


Edit: OP, you could try John's fork as he is attempting to improve bufferbloat with some tweaks like optimizing the ESFQ queue depth along with possibly switching from "tail drop" to "head drop" (used by CoDel).

 

[Nullity]

Yes I would look for another cause when I take that test I get an F for buffer bloat but have no issues with my internet what so ever. Also doing some further testing I have discovered that my buffer bloat is not even being caused by the router I get the same F score directly connected to my modem with no router in the mix so at least for me buffer bloat is at the ISP level so there in nothing that can be done to correct it. Comcast says buffer bloat should no longer be an issues once Docsis 3.1 is deployed sometime next year.

Rate-limit your downloads (or uploads) below your real-world maximums, which will avoid your ISP needing to rate-limit and build a buffer.

I could better describe how to avoid bufferbloat but you did not mention whether you got an "F" on upload, download, or both.

 

[Deleted member 22229]

Only on download and I am aware how to solve it using QOS but since it's not really a issue for me I don't bother with it. But Thank you for the advise...

 

[Nullity]

Only on download and I am aware how to solve it using QOS but since it's not really a issue for me I don't bother with it. But Thank you for the advise...

Aww, come on. Most of us are on this forum because we want our devices to perform better than average.

"F" is multisecond delays, iirc, which is obviously bad. I was not interested in bufferbloat either until I learned that I could tune my network so that simultaneously saturating upload and download need not impact my browsing. Though, I do only have a 15Mbit/768Kbit connection, so every little bit counts.



I am somewhat amazed that DOCSIS will include an AQM to combat bufferbloat. Nice to see the cable internet industry being so proactive.

 

[Deleted member 22229]

My devices perform perfectly I rarely max out my 100 Mbps connection.

 

[Nullity]

My devices perform perfectly I rarely max out my 100 Mbps connection.

Blah, I knew you would say that...

Bandwidth envy...

 

[Deleted member 22229]

Blah, I knew you would say that...

Bandwidth envy...

 

[Rich Brown]

Yes, ignore the buffer bloat report for now. That only comes into play if you deal with time-sensitive applications like VoIP or online gaming WHILE your connection is saturated...

Well, not exactly. There's a better way to think about it. On a micro-scale, your connection to the Internet is either busy (transmitting/receiving data) or idle. If it's idle, the packets do whistle right on through.

But when the link's actually doing something, other packets *will* be delayed.

So it becomes a probability game. If you're continually saturating the link, then it's 100% certain there'll be delay.

However, when you're browsing the web, you're (intermittently) saturating the link. Web pages these days are climbing to 2MBytes (see, for example http://www.soasta.com/blog/page-bloat-average-web-page-2-mb/) One hit can saturate a 15 mbps link for one second, or ~300 msec at 50 mbps.

That's plenty of delay to damage the performance of time sensitive applications if the router doesn't manage the flows of data to avoid high latency/lag.

 

[RMerlin]

That's plenty of delay to damage the performance of time sensitive applications if the router doesn't manage the flows of data to avoid high latency/lag.

Isn't that exactly what you quoted from my post?

 

[Nullity]

Isn't that exactly what you quoted from my post?

Yeah, but the primary intention of his post was to disagree with your "ignore the bufferbloat report" statement.

Though, your statement was an opinion and if we start down the road of arguing opinions, the internet explodes kitten shrapnel. Perhaps the finer points of queueing delay, stochastic probability, and networking calculus are overly pedantic (thanks Family Guy) in this thread...

 

[RMerlin]

Yeah, but the primary intention of his post was to disagree with your "ignore the bufferbloat report" statement.

By ignoring, I was referring to his current problem (problems loading websites). It's more likely to be either a DNS or an MTU issue than a bufferbloat one.

 

[Zirescu]

I just upgraded my FIOS from 75/75 to 150/150. Some web sites seem to have a delay opening, or even require me to refresh the browser to open them (not address specific, i don't think).

Likely the issue is DNS related, but if you're using some adblocking it could mess up a few website from loading correctly. Which browser are you using as well? I've observed some websites get hung when loading up the google analytics stuff.