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kimks3

join:2012-12-01
Richmond Hill, ON
Reviews:
·TekSavvy Cable
·TekSavvy DSL

1 edit

[Cable] Connection grinds to a halt when uploading...

I finally had my Cable 18 service installed today, but whenever there are *any* ongoing uploads in excess of ~10KB/s, my ping will skyrocket, and both up/down speeds will drop like a rock, rendering the internet useless (nothing loads properly, sites time out...)

Ping and speeds are fine when there are no uploads. Downloads can max the connection no problem.

Here are some speed/ping tests to demonstrate the issue:



Normal speeds with PC connected directly to modem



Dropbox application uploading in background



No uploads



Google music uploading in background

I had no issues maxing both upload and download on my old DSL connection.
Anyone from TSI or otherwise have any idea what's going on?
Even during the upload portion of the speed test, my connection will become unusable, and returns to normal once it is over.

Here is my SB6121 configuration:


I couldn't even upload the screenshot to imgur because it stays on "Pending..." forever.

kimks3

join:2012-12-01
Richmond Hill, ON
Reviews:
·TekSavvy Cable
·TekSavvy DSL

It's probably worth mentioning that connecting through the router makes no difference. As long as any device is uploading on the network, the connection becomes useless for everyone.

Here is the tracert; I'm not sure what it means, but maybe it will help:



TakeOffEh

@teksavvy.com
reply to kimks3

»[Cable] Does anyone else lag during max upload?


34764170

join:2007-09-06
Etobicoke, ON
reply to kimks3

said by kimks3:

I finally had my Cable 18 service installed today, but whenever there are any ongoing uploads, my ping will skyrocket, and both up/down speeds will drop like a rock, rendering the internet useless (nothing loads properly, sites time out...)

With the ridiculous asymmetry of connections provided by Rogers they're providing connections that are for all intents and purposes defective by design. The speed tiers Rogers is rolling out on their side helps to alleviate the problem, but it'll probably be awhile before TPIA providers have access to these new tiers. You can band aid the situation with your router to prioritize the ACK packets going back upstream to allow downloads/page loading/etc. to work properly but it still doesn't change the fact that the lack of upstream bandwidth has an impact on uploading/downloading at the same time.

kimks3

join:2012-12-01
Richmond Hill, ON
Reviews:
·TekSavvy Cable
·TekSavvy DSL
reply to TakeOffEh

Please read the post before responding. This occurs even when the upload speed is capped at 10KB/s. It is not due to the upstream becoming saturated and affecting the download speeds.

As an example, I can be downloading a file at 1MB/s, and if I unpause my Dropbox sync, the file download speed slowly drops to ~20KB/s. This happens even if I have Dropbox upload limited to 10KB/s.
My router shows that the traffic through the WAN port at this point is 20KB/s in and 10KB/s out. A far cry from the 2.25MB/s down and 64KB/s up advertised.

I've never experienced anything like this before, with either DSL or cable.


34764170

join:2007-09-06
Etobicoke, ON

said by kimks3:

Please read the post before responding. This occurs even when the upload speed is capped at 10KB/s. It is not due to the upstream becoming saturated and affecting the download speeds.

As an example, I can be downloading a file at 1MB/s, and if I unpause my Dropbox sync, the file download speed slowly drops to ~20KB/s. This happens even if I have Dropbox upload limited to

I don't know what is wrong but it sounds like there is something seriously wrong with your connection beyond how bad cable (and ADSL2+) usually is.

kimks3

join:2012-12-01
Richmond Hill, ON
Reviews:
·TekSavvy Cable
·TekSavvy DSL

Looks like I will have to call in to have this looked at. It's impossible to use the internet with anything uploading relatively large files (file sync, P2P, cloud backup...)
I know cable is pretty bad, but there is no way it is normally *this* bad.

If any TSI staff can give me some insight in the morning, I would appreciate it.



TakeOffEh

@teksavvy.com
reply to kimks3

According to your speed tests, you *are* coming close to maxing out your upload. You're only getting .39 mbits to start in the first test, and dropping to .13 mbits when uploading at 10KB/s-20KB/s.

Which explains your upload being killed. Your acknowledgements are getting starved out due to the little remaining upstream bandwidth, for some unknown reason.

I might have suggested disconnecting any other devices from the router, because I once had a system infected with malware that choked an entire LAN as long as it was connected to the router. But since you say you've been getting the same speeds directly connected to the modem, that couldn't be a factor.

As brad said, there's definitely something else wrong then. Which is strange, because your modem stats look good.


Vincentec

join:2012-12-06
reply to kimks3

I have the exact same issue here.

Teksavy@Markham....



TSI Marc
Premium,VIP
join:2006-06-23
Chatham, ON
kudos:28
reply to kimks3

Markham and Richmond Hill both dont have any congestion issues on our side.
--
Marc - CEO/TekSavvy


BoogaBooga

join:2004-06-12
Canada
Reviews:
·VMedia
·TekSavvy Cable
reply to kimks3

Speedtest.net is not always the best tool to use..

See how much dropbox is really using with a better measurement tool. This will tell you what's really coming out of your interface.
You can try »miechu.pl/freemeter/download.aspx or similar.

It may be that the local node in your neighborhood has congestion on the upload?


Foristality

join:2010-12-04
M2K 6T8
reply to kimks3

I have the exact same issue, expect my ping spikes like crazy but the download speed stays the same.

I'm on 28/1Mbps.

Very problematic, because I do gaming.

When others are on the networking, and are browsing the web. My ping spikes.

Constantly get booted from servers due to high ping.

This is completely insane, I paid a premium price to move from dsl to cable and things got worse instead of getting better.

I will try limiting my upload speed using QoS. and I'll see if that solves the problem.

Rogers did some sort of 18 day ping test, and they said everything is fine, but obviously it isn't on my end.

MCcowan and Kingston, Scarborough.



jmck
formerly 'shaded'

join:2010-10-02
Ottawa, ON

well you're sharing a pretty poor upstream and downstream with a few people (28mbit down is actually pretty poor when if you have 1-2 ppl streaming a 1080p youtube).


34764170

join:2007-09-06
Etobicoke, ON

said by jmck:

well you're sharing a pretty poor upstream and downstream with a few people (28mbit down is actually pretty poor when if you have 1-2 ppl streaming a 1080p youtube).

That's why Rogers needs to roll out the new speed tiers and the TPIA providers need this badly.

BrianON

join:2011-09-30
Ottawa, ON
Reviews:
·TekSavvy Cable

2 edits

I have 3mbs/256kbps cable and never have a latency problem in online games even with a Netflix movie playing, syncing 100mb of new pictures in Skydrive and downloading an ISO at the same time. I use a DLINK DIR-655 router with QoS enabled with uplink speed manually set to 256kbps, automatic classification and enable traffic Shaping set (not the best router but has worked well for me).

Your numbers do seem worse than just an up-link saturation issue would usually cause but still worth a shot to try a router with a decent working QoS engine/feature. Might also want to check for a signal issue by checking the modem signal stats page while the problem is occurring.



pph

@teksavvy.com
reply to kimks3

I have the same issue. Whenever I am uploading no matter what speed, it affects download speed. Upstreams and downstreams are using different bands. They are not supposed to affect each other if Rogers set it up properly.



TSI Gabe
Router of Packets
Premium,VIP
join:2007-01-03
Gatineau, QC
kudos:7

This is normal, even on a Gbps+ connection, when you get close to the saturation point on your upload channel your TCP sessions aren't getting ACK'd back or at least not fast enough and causes TCP to scale down.

The issue is aggravated even further on DSL or Cable since they are asynchronous



NotNormal

@bell.ca

This is nowhere near normal. The op states they have a 18000/512 service where a upload at a mere 128kbps chokes the download to 200. Using 128 out of 512 should not be anywhere near saturating the upload.



TSI Gabe
Router of Packets
Premium,VIP
join:2007-01-03
Gatineau, QC
kudos:7

The OP did not specify exactly what speed he was uploading at the time of the test. I suspect that it was more than 10KB/s since it was a dropbox upload which normally takes whatever bandwidth you have available.


BrianON

join:2011-09-30
Ottawa, ON
Reviews:
·TekSavvy Cable
reply to TSI Gabe

Sure the behaviour is normal for a saturated upstream connection but from the information posted I think problem isn't local to the user or with the backhaul link to Teksavvy. That means someplace between those there *IS* a problem. A miss-configured port, router, wrong cables used or whatever.

What node people are on might help track down the problem. I am on Ottawa's richmond and do not have problems.



TSI Gabe
Router of Packets
Premium,VIP
join:2007-01-03
Gatineau, QC
kudos:7

one thing that pops to mind is that somehow the ethernet connection to the modem negotiated in half-duplex. I've seen this a few times


pph

join:2012-12-07
M1S
reply to kimks3

This does not make sense. We are talking about broadband internet not traditional internet. Bandwidth is divided into multiple channels. Each channel uses different frequency. They don't interfere with each other.
One physical cable,
8 downstream channels
4 upstream channels
If the saturated upstream channels can slow down downstream channels,
there is no point to have multiple channels.


BrianON

join:2011-09-30
Ottawa, ON
Reviews:
·TekSavvy Cable

said by pph:

This does not make sense. We are talking about broadband internet not traditional internet. Bandwidth is divided into multiple channels. Each channel uses different frequency. They don't interfere with each other.
One physical cable,
8 downstream channels
4 upstream channels
If the saturated upstream channels can slow down downstream channels,
there is no point to have multiple channels.

TCP/IP (which most connections use) requires response packets that say which packets have been received OK and that it can send more. If your downloading and your response packets don't make it due to congestion or something else the download will slow down as the sender throttles back on sending packets.


random

@teksavvy.com
reply to TSI Gabe

>one thing that pops to mind is that somehow the ethernet connection to the modem negotiated in half-duplex.

The data rate is 1Gbps (or 100Mbps for older routers). Transferring 10KBytes/sec would be on the order of 100kbps of data which would only take up a tiny fraction of the time slots. That's 0.1/100 or 0.1/1000 of the time slots.

Same type of linear thinking reasoning that tell people to check Ethernet cables or the power supply when the person can see the modem webpage. A big waste of time that shows that you can't debug systematically.


Foristality

join:2010-12-04
M2K 6T8
reply to kimks3

How do I get QoS going?

I have a DD-WRT on my router.

Any tutorials?


pph

join:2012-12-07
M1S
reply to kimks3

I suspect half duplex too. That would explain it. However it is year 2012. It should be full duplex these days.

By the way, TCP/IP is OSI layer 3. This upload/download issue is layer 2 and layer 1. Layer 1 is the physical layer. We are talking about broadband not single band. Broadband has many channels. Each channel is independent.


34764170

join:2007-09-06
Etobicoke, ON

said by pph:

I suspect half duplex too. That would explain it. However it is year 2012. It should be full duplex these days.

It should be but there is the remote chance there is an auto-neg issue. Surprisingly enough I have run into this between modern day equipment from Cisco (both ends) for example.

Foristality

join:2010-12-04
M2K 6T8

1 edit
reply to kimks3

I think I found a solution. I just set up QoS and it actually works.

Ping usually spiked from 30 ms to 500 ms+ when uploading files, but with the QoS the ping spikes from 30 ms to only 60 ms.

If you are running a DD-WRT I can help you set up QoS.

Which might reduce the lag.

Reply to this if you are interested.


graniterock

join:2003-03-14
London, ON
Reviews:
·WIND Mobile
·TekSavvy Cable
reply to kimks3

said by kimks3:

Please read the post before responding. This occurs even when the upload speed is capped at 10KB/s. It is not due to the upstream becoming saturated and affecting the download speeds.

As an example, I can be downloading a file at 1MB/s, and if I unpause my Dropbox sync, the file download speed slowly drops to ~20KB/s. This happens even if I have Dropbox upload limited to

Have you had any speedtests that max out the upload? I noticed the ones you posted don't seem to. Have you tried connecting without the router?

FWIW I have a 28/1 connection. I ended up having to replace my router as it couldn't handle the higher speeds esp with QOS turned on and then install tomato on the new router to get proper QOS. Surprising to me, I found without QOS using anything more than about 25% upload capacity caused issues with my VOIP.

BrianON

join:2011-09-30
Ottawa, ON
Reviews:
·TekSavvy Cable

said by graniterock:

FWIW I have a 28/1 connection. I ended up having to replace my router as it couldn't handle the higher speeds esp with QOS turned on and then install tomato on the new router to get proper QOS. Surprising to me, I found without QOS using anything more than about 25% upload capacity caused issues with my VOIP.

The prioritization part of QoS helps VOIP a lot. Normally a router sends packets in the same order they were received. So a VOIP packet arriving after several large dropbox upload packets would have to wait. With prioritization the VOIP packet gets sent first.