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n8nu
Anon
2012-Aug-19 8:58 pm
[Extreme Plus] Uploading kills downloading speedsRecently my Rogers Extreme Plus service is taking a dive. In 8 years I've never had an issue. The last 5 days as soon as I upload anything (eg photos to Smugmug), my download speed completely dies.
Without uploading anything my download speeds easily hit 50+ Mbps (according to speedtest).
Once I start uploading files my download speed drops to .33 Mbps or even less. Often I can't even load a web site.
Is this Rogers way to stopping people from uploading/file sharing/etc?
I have the SMCD3GN modem in modem only (bridge) mode as I'm using a independent router. |
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Anzio
Member
2012-Aug-19 9:14 pm
Pretty sure this is typical behaviour. At least I thought it was. Since you're uploading at 100% of your upload speed (presumably), you're using your entire upload bandwidth.
When downloading, your machine needs to request the packets from the server (upload a request) before it can begin downloading the next burst of data. Since it can't upload the request packets at a fast enough rate- you're left over with hiccups (or even slow-to-start downloads). Latency gets hit pretty hard too.
I know I'm not technically correct about what exactly is causing this, but I know that it has something to do with uploading the request for the download.
This is the case for any TCP/IP connection.
Perhaps the solution would be some kind of QoS implementation? |
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cork1958Cork Premium Member join:2000-02-26 |
cork1958
Premium Member
2012-Aug-19 10:07 pm
Anzio is totally correct unless this line of your post:
"Once I start uploading files my download speed drops to .33 Mbps or even less. Often I can't even load a web site:
is incorrectly stated. You typed .33Mbps. Is that dot supposed to be in front of the 33? Otherwise, if you meant 33Mbps, you are doing fine and nothing you can do about it except when uploading, don't do anything else.
That is just how internet traffic has ALWAYS worked. |
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Dcite join:2006-05-12 Mississauga, ON |
to n8nu
Uploads tends to kill downloads, If it's 0.33Mbps download, consider putting an upload speed limit, after running a speed test to see how fast you can upload, try to set a limit which is 160kbit(or 20k/sec) lower than your maximum upload to not suffer as much in performance.
But as another posts, if you still have 3.3Mbit or better, I won't worry too much. |
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n8nu
Anon
2012-Aug-20 7:21 am
Sadly 0.33 Mbps was correct. I did another speedtest and it was 0.15 Mbps. What's confusing is that I've been on Extreme Plus for years and it seems to be an issue now. Got no problems when not uploading: » www.speedtest.net/result ··· 7591.pngWhen uploading: » www.speedtest.net/result ··· 0295.pngAnd since I can't do anything on another computer, then I am simply saturating my modem? |
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mozerdLight Will Pierce The Darkness MVM join:2004-04-23 Nepean, ON |
to n8nu
DOCSIS 3.0 should be FULL DUPLEX .... so something is wrong with your node .... I would check with Rogers Tech support and have them do some tests Although Rogers for the most part offers asymmetric communications [ symmetric and asymmetric] your upload speed should not be impacted by your download speed UNLESS your NODE is saturated in which case YOU will have the type of experience you\re currently seeing. Since your SMC is in Bridge mode it is possible that Your ROUTER may be having issues so you need to make sure that its not the router. |
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sbrook Mod join:2001-12-14 Ottawa |
to n8nu
The explanations here of what's happening isn't quite right. It sounds like there are two things coming into play.
First it sounds like Rogers throttling is coming into play. They haven't removed it from many areas yet.
Second when you download something, after the source sends you a packet of data, your computer has to acknowledge receipt with something called an "ACK packet" ... this is queued up with all the other packets in your send queue. If you've filled the send queue up with a lot of data to send, then it can take a while to get sent. Which means that the system sending you data doesn't get its "ACK"s in a timely manner, so it slows down it's sending,
Cable modems are not really full duplex ... although the input to them may be. Because they share the up and downstream paths, the modem has to buffer the upstream and its buffers are only so big, so, if you do a heavy upload, your modem buffers as much as it can, then discards the overflow, relying on normal protocols to sort out the mess that creates with timeouts and retransmits. |
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mozerdLight Will Pierce The Darkness MVM join:2004-04-23 Nepean, ON 1 edit |
mozerd
MVM
2012-Aug-20 12:56 pm
I agree that throttling may be coming into play .. the rest I do NOT agree with the esteemed sbrook -- especially with DOCSIS 3.0 Gear. I tested this many times and my [and many others] upstream has not as yet been impacted by near saturated downstream traffic OTHERWISE real-time applications [like VoIP 4 to 8 lines] that require full duplex capability would fail frequently with unacceptable call quality. Poor quality Routers and cheap NICS do have issues. |
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to n8nu
its a nice lie but in mod 90's i had a 700kilobyye/sec down and 400 kilobyte up with rogers and ask yourself why seed boxes and dedicated boxes have the same up and down speed .... its all a cute lie so you don't use the services to learn about it stuff on your own..... |
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to mozerd
said by mozerd:I agree that throttling may be coming into play .. the rest I do NOT agree with the esteemed sbrook -- especially with DOCSIS 3.0 Gear. Agreed. DOCSIS 3.0 features channel bonding, which enables multiple downstream and upstream channels to be used together at the same time by a single subscriber. said by mozerd:I tested this many times and my [and many others] upstream has not as yet been impacted by near saturated downstream traffic. Yes, but downstream traffic can be impacted by near saturated upstream as sbrook suggests. Still, the OP appears to have a method that's worked in the past so maybe something in the network, somewhere, has changed? I'd suggest rate limiting the upload to see the effect on download speeds. |
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to n8nu
Saturating either UP or DOWN will affect the other to varying degrees. Saturating the UPstream will kill the DOWNstream, on my 75Mb, it will take me down to around 1Mb... whereas saturating the downstream, ie. with multi-connected news, it will knock the UPstream down, so on my 2Mb it will usually knock it down to 1Mb or so, without chance of going higher till the DOWNstream lets up or stops.
The fun of Rogers... that is why 75Mb/2Mb is a joke, rogers needs to greatly improve the UPstream before offerring any crazy DOWNstream speeds. |
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sbrook Mod join:2001-12-14 Ottawa |
to n8nu
4 upstream channels may reduce the risk of upstream saturation, but it still can happen if you fill the upstream, particularly on the primary channel, since that is used by a lot of the modem control with the CMTS.
Higher than normal use on the segment's upstream will impact an individual modem's upstream, since your modem may not get acknowledged when it puts in a "Request to send a packet" ... which remains a freeforall. |
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justaguy to n8nu
Anon
2012-Aug-20 3:44 pm
to n8nu
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n8nu
Anon
2012-Aug-21 1:56 am
In my case nothing has changed in over 2 years (hardware at home, etc). So curious why the change in the way the upload kills the download in the last week. I am using a Mac and Air Port Extreme router. Here are some speed tests: Done without uploading: » www.speedtest.net/result ··· 8212.pngDone while uploading (uploading at approx 125 KB/s): » www.speedtest.net/result ··· 9857.pngDone immediately after upload cancelled: » www.speedtest.net/result ··· 1124.pngDone while limiting upload to 80 KB/s: » www.speedtest.net/result ··· 5795.pngSo guess I simply have to save my uploads to when I don't need to download much, or limit the upload speed |
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sbrook Mod join:2001-12-14 Ottawa |
sbrook
Mod
2012-Aug-21 5:27 am
That behaviour reeks of Rogers throttling boxes. |
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N8webs join:2004-12-25 Waterloo, ON |
N8webs
Member
2012-Aug-21 9:33 am
So is there any point in calling Rogers to complain? |
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sbrook Mod join:2001-12-14 Ottawa |
sbrook
Mod
2012-Aug-21 11:12 am
Nope, unless it continues beyond the date that Rogers has said they're ceasing throttling |
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justaguy to n8nu
Anon
2012-Aug-21 2:47 pm
to n8nu
Try it while limiting your upload to 80% of your maximum |
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N8webs join:2004-12-25 Waterloo, ON 1 edit |
N8webs
Member
2012-Aug-22 5:15 am
This was done limiting my upload to 80 KB/s. Looks like my upload can max at about 130ish KB/s » www.speedtest.net/result ··· 5795.png |
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jimgettysc to n8nu
Anon
2012-Aug-28 12:16 am
to n8nu
Looks like bufferbloat to me.
Run netalyzr to get the upstream buffering number. |
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trog join:2001-03-25 Scarborough, ON |
to sbrook
You could check to see if they claim to have removed throttling from your area: » promo.orderrogers.ca/tra ··· -traffic |
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Ree
Member
2012-Aug-31 11:46 am
Handy, thanks! |
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