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jcremin

join:2009-12-22
Siren, WI
kudos:3

Youtube Buffering

Hey Everyone, I've been starting to get more regular complaints about people having issues watching youtube videos. We've always gotten complaints here and there, but it has typically been an opportunity to upsell them to a higher plan, which has typically fixed the issues. Now I know my speeds are fairly low, currently 768k, 1meg, and 1.5megs, but the last few people that we had test a 1.5 meg connection said it was just as bad as the 768k, even when using the lower quality videos (240p, 360p, and 480p).

I did some testing of my own the other day, and I'm really starting to think there is a bigger issue here. At my home, I can get about 6-7mbps, but just for testing sake I set myself to a 5 meg queue. Most videos seemed fine and would play all the way up to 1080p streaming at 5megs until I assume the buffer was full and it would start downloading in bursts. But then all of a sudden I would start having issues where the video would only stream at 2-3 megs and I'd get a lot of buffering. I changed my route to point myself through a backup DSL connection, and then the video would stream at the full 5 megs again.

I haven't had enough time to try to reproduce that, but I did watch long enough to know that my customer's aren't crazy. Even when I would start having issues watching a video, I could start a speed test to just about anywhere on the net and the connection would max out at 5 megs again, so it isn't a throughput issue.

I'm not much of a video guy, but I'm assuming that different videos are encoded differently, so one 480p video may or may not have the same bitrate as another 480p video. Is that correct? I noticed when I was initially testing that the only thing that worked fine at 768k was the lowest 240p quality. But then later I was doing some more testing and watched a 480p video on the same 768k speed.

Anyone else seeing anything similar? Should I keep troubleshooting, or does Youtube just seem to have an issue? I don't seem to be getting nearly as many complaints about Netflix, and none about Hulu, Vimeo, etc. If I do get someone complaining about Netflix, a simple speed boost ALWAYS seems to help unless they are specifically looking for HD video.


treichhart

join:2006-12-12
If they want HD video they need at least 2-3meg on Youtube anything below that its going to buffer like crazy bc I have 7meg FTTH and youtube videos still buffer for me.

jcremin

join:2009-12-22
Siren, WI
kudos:3
said by treichhart:

I have 7meg FTTH and youtube videos still buffer for me.

That's kind of my point. While I tested various qualities at various speeds, some of my testing was done at 5 megs, and even then many times the videos wouldn't play right.

Have you ever watched your usage on that 7 meg FTTH connection to see how much of it was actually being used?

jcremin

join:2009-12-22
Siren, WI
kudos:3
reply to jcremin
Click for full size
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I'm attaching a few screenshots to this thread to explain in a bit more detail:

screen1.jpg - I'm routed through my main provider like normal and running a speedtest, which is running pretty much right at 5 megs, which is what I have the queue for my connection set at for testing purposes. You can see the speedtest.net window open on the left, and the Mikrotik window on the right showing the same throughput.

screen2.jpg - As soon as the speedtest finishes (and while still routed through my main provider), I start playing a Youtube video at 1080p, which should essentially max out the 5 megs, at least until enough of the video is buffered. The video stops to buffer a lot, and you can see that the video is only downloading at around 3 megs (and kinda choppy) even though I literally just finished a speedtest that pushed 5 megs without any problems.

screen3.jpg - I simply change my route to point at our backup DSL connection and restart the video, which plays fine without any buffering issues. As you can see it is downloading at 5 megs (the Winbox window happened to show 5.5 megs at the moment I took the screenshot despite myself being queued at 5 megs) and the download speed is much more consistent.

I've been working with my upstream provider (who is another WISP), and they claim they haven't really been noticing the same issues, but that's not to say they just aren't getting reported to them like my customers have been. I can't seem to find anything that would indicate issues along the way for my main provider. Like I mentioned, I should have more than enough bandwidth (If I'm at my office on a little better connection, I can test at 10-15 megs without an issue) and the latency is fine. No QOS that should be affecting anything.

I just can't seem to figure out what would be causing it. If I re-ran the tests tonight, the video may play fine, or it may not. Doesn't seem to be terribly consistent, which make it hard to track down.


treichhart

join:2006-12-12
reply to jcremin
Joe I have not see how much of my 7meg FTTH connection is actually being used on youtube video but I could through my smoothwall router later on.

jcremin

join:2009-12-22
Siren, WI
kudos:3
said by treichhart:

Joe I have not see how much of my 7meg FTTH connection is actually being used on youtube video but I could through my smoothwall router later on.

That would be great, especially if you can find a video that seems to be having a hard time keeping up.


treichhart

join:2006-12-12
reply to jcremin
Joe I can tell you all videos I watch it buffers like crap on my connection.

gunther_01
Premium
join:2004-03-29
Saybrook, IL
reply to jcremin
Are you graphing your upstream availability? Also, while not so typical, is it possible that your MT is out of steam for the amount of rules, and bandwidth, and such that your primary feed is offering and the MT is regulating?

It would almost have to be the upstream connection IMO if your DSL line works fine. Unless some strange routing issues that are causing hickups of some sort
--
»www.wirelessdatanet.net


John Galt
Forward, March
Premium
join:2004-09-30
Happy Camp
kudos:8
reply to jcremin
Check to see if you have multiple versions of Flash installed.

I had real problems until I removed the old versions, and disabled the PepperFlash version in Chrome.

jcremin

join:2009-12-22
Siren, WI
kudos:3
reply to gunther_01
said by gunther_01:

Are you graphing your upstream availability? Also, while not so typical, is it possible that your MT is out of steam for the amount of rules, and bandwidth, and such that your primary feed is offering and the MT is regulating?

Yes, I am graphing, but I have plenty of bandwidth available, so that's not an issue. I had considered an overloaded router, but it seems to happen the same at 2am as it does at 8pm. I don't run too many rules, and my CPU consumption maxes out at about 50% during peak time. During off-peak it hits about 20% tops.

said by gunther_01:

It would almost have to be the upstream connection IMO if your DSL line works fine. Unless some strange routing issues that are causing hickups of some sort

Well, that's what I was thinking too, but I'm leaning more towards it being that when I'm on the DSL, it just happens to pick better servers with better routes for whatever reason. I tried running some tests over the last hour or two, and it seemed like at first it would switch back and forth to two different servers depending on which route I was using. I tried to switch routes quickly and then jump ahead in the video to keep it from switching servers, and it appeared to keep running nicely the first time I did that. Then I tried testing the other way, and it was picking different servers but running fine again.

And that seems to be the hardest thing... sometimes it sucks, other times it seems to run fine, leading me to believe that it is just giving me more bad routes to servers when I'm on my primary connection as opposed to the DSL. I do know that this IP range was assigned to a Canadian ISP before my provider got it about a year ago. One thing I had considered is if it was trying to route me to servers based on thinking the traffic was still coming from Canada, but the IP switch happened about a year ago, and I would have thought the problem would have shown up right away and worked itself out by now, but it seems to have just started getting worse recently.

jcremin

join:2009-12-22
Siren, WI
kudos:3

1 recommendation

reply to John Galt
said by John Galt:

Check to see if you have multiple versions of Flash installed.

I had real problems until I removed the old versions, and disabled the PepperFlash version in Chrome.

Thanks for the tip... I only have one version of Flash installed on my main computer (from what I can tell) but the same thing seems to happen on multiple computers (and from multiple clients), so I don't think is likely the cause of the specific issue I'm trying to figure out here... But I'll keep my eye open for it just in case.

jcremin

join:2009-12-22
Siren, WI
kudos:3
reply to treichhart
said by treichhart:

Joe I can tell you all videos I watch it buffers like crap on my connection.

Doing a bit more testing, it appears that 5 megs is fine for some 1080p videos, and just a little under-powered for others. If you are in fact getting your full 7 megs consistently, I believe that every 1080p youtube video should stream without interruption, so if they are all buffering (even lower quality ones) something definitely doesn't sound right.

gunther_01
Premium
join:2004-03-29
Saybrook, IL
reply to jcremin
Try running a traceroute while your streaming. Maybe you will catch something there if routes are changing mid stream. Just in case.
--
»www.wirelessdatanet.net


John Galt
Forward, March
Premium
join:2004-09-30
Happy Camp
kudos:8
reply to jcremin
This was posted by tschmidt See Profile recently:

»www.itc23.com/fileadmin/ITC23_fi···s/a5.pdf

spectrumhead

join:2009-05-03
reply to jcremin
If you have latency or even a very small number of packet loss on your connection, you cant get youtube at full speed.

prairiesky

join:2008-12-08
canada
kudos:2
reply to jcremin
I have all kinds of issues. Some of my customers have 2 meg connections and are having troubles. I haven't really looked into why.

I also hate how they've limited the buffer time. I know there's work arounds for that, but i can't be explaining those to customers all the time.

voxframe

join:2010-08-02
reply to jcremin
There's two issues here I've seen cause similar problems.

1) Jitter. Latency isn't a huge problem, it's jitter, or worse packetloss, that usually comes with high latency. Run some jitter tests on both of your connections and see what you get. I'm pretty sure they will be very different.

2) Routing/QoS/Etc. You said the upstream provider you're having problems with is another WISP, well depending on their equipment, routing, and QoS implementations, it could have a serious impact on you. You may also be blind to a lot of what they do depending on how much info they share with you.

I transport Youtube over wireless to my clients on 5/1 profiles and have zero problems, but it's a careful balance. A few bad QoS settings or a bad RF issue and it'll screw the entire thing up. Sounds like you may be getting a touch of this.


John Galt
Forward, March
Premium
join:2004-09-30
Happy Camp
kudos:8
reply to jcremin
said by jcremin:

But I'll keep my eye open for it just in case.

So noted, but just to follow up here...I've also found that Java leaves multiple versions active, too.

Why these programmers don't clean up the deadwood after they install is beyond me...

jcremin

join:2009-12-22
Siren, WI
kudos:3
reply to gunther_01
said by gunther_01:

Try running a traceroute while your streaming. Maybe you will catch something there if routes are changing mid stream. Just in case.

Other than slightly different routes to different IP addresses depending on the server the video decides to stream from, the routes look consistent and don't appear to change at all mid-stream, or ever for that matter.

jcremin

join:2009-12-22
Siren, WI
kudos:3
reply to John Galt
said by John Galt:

This was posted by tschmidt See Profile recently: »www.itc23.com/fileadmin/ITC23_fi···s/a5.pdf

I'll have to check that out when I have a little more time to read it over. Thanks for the link!

jcremin

join:2009-12-22
Siren, WI
kudos:3
reply to prairiesky
said by prairiesky:

I have all kinds of issues. Some of my customers have 2 meg connections and are having troubles. I haven't really looked into why.

In doing some general searches, I found plenty of complaints from other people, some of those on sub-megabit speeds and some on 100mbps fiber, with many being 10, 20, 30 meg connections.

Lots of theories, but nothing that seems to work consistently. Some suggested MTU changes, which sounded plausible, but didn't seem to make a bit of difference for me no matter what I set them to.

I've read a lot of general consensus that Youtube just has overloaded servers, which I guess might make sense on a regional level, but then I would think everyone in that region would have the same issues.

jcremin

join:2009-12-22
Siren, WI
kudos:3
reply to voxframe
said by voxframe:

There's two issues here I've seen cause similar problems.

1) Jitter. Latency isn't a huge problem, it's jitter, or worse packetloss, that usually comes with high latency. Run some jitter tests on both of your connections and see what you get. I'm pretty sure they will be very different.

I know some customers have iffy connctions with a bit of packet loss, but at least where I'm doing my testing from rarely ever drops a single ping. Do you have a good online jitter test you would recommend? I do know I have some for various customers, but again, I think where I have been testing from is a fairly solid connection. What level of jitter would you say is the threshold where it becomes unacceptable?

said by voxframe:

2) Routing/QoS/Etc. You said the upstream provider you're having problems with is another WISP, well depending on their equipment, routing, and QoS implementations, it could have a serious impact on you. You may also be blind to a lot of what they do depending on how much info they share with you.

Yes, they are a WISP, but I bypass the wireless side of their network. I have a dedicated point to point link from one of my towers directly to the water tower near there office. From there, I have another dedicated link directly to their office, which plugs into my own edge router which plugs into the same switch their fiber backhaulk comes into which feeds their core router for their network.

So I essentially bypass any of their QOS, routers, or wireless links. I manage everything up to where it plugs into the fiber switch. From the fiber switch, it runs over a leased fiber down to a datacenter, where it plugs into one more router to handle the connection to their provider (Cogent). Last I checked, there is no QOS, overloaded routers, or packet loss between Cogent and my edge router. I actually worked for the WISP when I was just starting my own and they have been extremely accommodating in letting me get my network setup with theirs and allowing me access into their routers for troubleshooting. I highly doubt anything on their network is causing it, but I'm not ruling anything out at this point.

said by voxframe:

I transport Youtube over wireless to my clients on 5/1 profiles and have zero problems, but it's a careful balance. A few bad QoS settings or a bad RF issue and it'll screw the entire thing up. Sounds like you may be getting a touch of this.

So can a 5/1 speed stream every HD 1080p Youtube video without buffering issues? I had myself set to 5/5 at home last night and it seemed some videos would stream at that resolution and some wouldn't, even if it appeared to be utilizing the full 5 megs.

jcremin

join:2009-12-22
Siren, WI
kudos:3
reply to John Galt
said by John Galt:

This was posted by tschmidt See Profile recently: »www.itc23.com/fileadmin/ITC23_fi···s/a5.pdf

I got a chance to read through this tonight. Interesting read.

Also, regarding the link you sent me to the other thread (»Youtube videos are slow), I am also using Google's public DNS servers. I wonder if it makes more sense to try to use my own??? I assumed that if anyone's DNS servers would provide decent results for Youtube, it would be their own. I might try it just to see what happens, although I'm guess it won't change much.

I also read through the Google groups thread from that other DSLR page (»productforums.google.com/forum/#···5-false]) and it sure sounds like a lot of people are really unhappy with Youtube right now, despite having connections that you would think wouldn't have any issues, and many report that other streaming sites work fine. Maybe I'm wasting my time with Youtube and should tell my customers to use Hulu and other sites instead???

Has anyone else tried the HTML5 version of Youtube? I don't expect it will make a difference, but I'm going to play with it and see how it works.

jcremin

join:2009-12-22
Siren, WI
kudos:3
reply to voxframe
said by voxframe:

Run some jitter tests on both of your connections and see what you get. I'm pretty sure they will be very different.

FYI, I ran a handful of tests from pingtest.net, and on average, the ping to most servers was around 60ms, and the jitter was typically under 15ms.