dslreports logo
site
 
    All Forums Hot Topics Gallery
spc

spacer




how-to block ads


Search Topic:
uniqs
2336
share rss forum feed

Javik
Premium
join:2006-10-02
Gilman, WI

[CenturyTel] Spiky, jumpy, wavering DSL speed? Fast, slow, fast,

Does anyone know what would cause the DSL speed to rapidly jump fast and slow, several times a second, over and over? Speed is not constant at all.

Windows 7, Task Manager update speed is Fast:



(54 meg 802.11g, 2.5% of that is 1.35 megabit)

So, although I can occasionally get about 1.3 meg, it averages out to half that or less:



It's not the wifi connection. The Asus RT-N56U router has an FTP file sharing option if I plug in a USB memory stick. Here is a 700 meg download from the router via wifi, also with Task Manager doing fast refresh:




,

,

And since CenturyLink support whines about using wifi, here is direct to the router using Windows XP:






--
CenturyLink remote pedestal: RUBY, 10 miles west of Gilman, WI
»Rural Century Telephone remote terminal unit
»Name of this pole-mount outdoor telco canister?


Packet

@qwest.net

Re: [CenturyTel] Spiky, jumpy, wavering DSL speed? Fast, slow, f

Enterprise Performance Network Optimization is an old but good book on networks. One of the key things of networks is they are bursty. Bursty as in spiky. Wifi even more so.

I own an Asus RT-N13U. Its had some bad reviews. IF I leave it on it becomes disconnected till a reboot in a day or less. Using an after market firmware based on linux is supposed to fix that issue.

It would be great if the router worked well with the USB flash drive but not everything works as well as designed in the lab. The 2nd graph showing a wifi connection using the usb as a download location I am guessing. It would be difficult to measure performance of that particular device and compare its performance in downloading compared to downloading say a torrent from multiple external locations. Thats right there and it depends on your particular network devices and drivers and how well they function or get interference or how consistent as it looks the download is.

The others are two different PC's one a laptop? IDK You have 7 listed first in task manager and XP later with a direct connection.
This is only a graphical inhouse to windows representation of the burstyness of the connection. You will see spikes in just even browsing. Task manager's levels mean little unless its flatlining at the top and you cant get the PC to respond any more.

There are better tools to measure this. On top of it you can't see the various hidden protocols that Windows sends packets out when you make a connection. Download Wireshark (formerly Ethereal) and capture a conneciton and you will see there is much more than plugging it in like a power cord. Windows has great number of different basic hello types of protocols trying to announce its presense and find other hosts. Your router also will produce packets. This is how they communicate. Also CL's router will produce packets or their access server / router DSLAM or ASDL connection. All of these packets in the end transfering data wether its from the usb(stick) flash drive or from the internet get wrapped in other frames to create an entire wrap and unwrap process to get the data from the source to the destination. This creates overhead.
The is a lot of communication between source and destination involved in telling the source whether or not the packet came through corrupted or at all. Its not much but it all adds up.

Meanwhile windows sitting there running task manager is sending out its own hello where am I requests and announcements not to mention 3rd party installs that create enourmous overhead looking for updates and licensing. Browsers that use Java vs No Script FF addon blocking and browsers that accept adobe macromedia flash support.

Wifi of any type is effected by various other signals. Just try a pair of wifi headphones and the interference they get from routers, cordless phones of different frequencies and you will experience interference. Driving past some local cell towers and wifi cafe I get a huge amount of rf interference on my am radios. Which one it is I am not sure I thinking the cafe.

Not to mention high voltage etc. It really depends on where you are testing and how well its protected from neighboring interference of high voltage, low voltage, rf, cell towers, dB from bad CATV cable leakage etc. Thieving of your bandwidth etc. I know all supposed to be separated from eachother.

What is the speed you are paying for? Is this something like 896/256? Download wireshark and attempt to capture the same ethernet events and you may find more imformation to go on rather than task managers graphs.


Javik
Premium
join:2006-10-02
Gilman, WI
reply to Javik

I suppose I should mention I'm a network administrator for two school districts, I manage pfSense router/firewall software. I know all that.

We're paying for 1.5 meg DSL, but usually only get 0.5 to 0.7 of it.

The Asus router I have is very highly rated and a hundred bucks or more so it's not a cheap low-grade device.

,

These throughput graphs for Windows 7 and Windows XP are showing performance using either SpeedTest.net or CenturyLink's own speed test website.

Speed tests are blasting hundreds of packets per second to run the connection as fast as possible, and to saturate the line. The throughput graph should be a solid line running near-horizontal at maximum speed all through the test, not jumping repeatedly from 100% to 0% every half-second or so.

And actually it WAS doing max performance in a steady line, when the DSL was new about five years ago.

I've replaced the modem and router a couple times now. I've put an APC lightning strike surge protector on the line.

I'm getting real close to replacing all the house-wide filters that CenturyLink installed in the telco boxes, and replacing all the outside wiring just in case this is due to corrosion.
--
CenturyLink remote pedestal: RUBY, 10 miles west of Gilman, WI
»Rural Century Telephone remote terminal unit
»Name of this pole-mount outdoor telco canister?


brad152

join:2006-07-27
Phoenix, AZ
Reviews:
·CenturyLink
reply to Javik

Have you simply called CL to see if maybe they put a few too many people on the DSLAM?

Spikes up and down like that can be signal related on the line, but in my experiences dealing with AT&T back east generally meant that they just simply put too many people on the node, and the dropoff was the node giving someone else that bandwidth for a second or so.


CenturyLink
VIP
join:2009-03-09
Boise, ID
kudos:7
reply to Javik

Hello Javik,

Sorry to hear about the DSL speed issue. We can investigate this for you if you'll provide your account number, etc.

You can send this to us using either talktous@centurylink.com or »bit.ly/IArNlt.

Thank you,

Tom Spenner
Social Media Manager
CenturyLink.com


PhoneDude

join:2013-05-03
Houston, TX
reply to Javik


I've replaced the modem and router a couple times now. I've put an APC lightning strike surge protector on the line.


PhoneDude

join:2013-05-03
Houston, TX

I strongly suggest removing the modem from the surge protector. They are often the culprit with noise problems.

The easiest way to eliminate any problems in your house is to plug the modem directly into the NID on the side of the house. If speeds are the same you have sufficient ammunition to arm twist a resolution.