# Help! Cable Internet has slow periods, Comcast says everything is fine



## Mtrpls (May 26, 2003)

Hello all,

I have a Compaq Presario laptop with wireless internet functionality, and connect to the cable modem via a wireless router. For the several months I've had the internet through Comcast, everything seemed to be fine. Very high speeds, constant high-speed connectivity, and reliability.

These last few days, however, have been anything but pleasant. I noticed the internet signal is still high-speed, but often becomes very, very sluggish and lethargic at times. For example, I can go through a period of web surfing where I have maybe 45 minutes of constant, high-speed connectivity, but then everything will suddenly s - l - o - w - - d - o - w - n for periods of 15 to 20 minutes. Then, suddenly, everything will be high speed again, and pages will load rapidly for maybe 20 minutes. Then, again, 15 minutes of pure sluggish frustration, where simple HTML files with few graphics will take upwards of 30 seconds to load. Then, 15 minutes of high speed, then 10 minutes of slow. Sometimes the internet connection is lost altogether, (i.e. Page Cannot be Displayed). 

This problem had become very apparent while I view streaming media; at first, everything was nice and smooth, then it all started sputtering, going in and out, pausing, then it would pick up again, then everthing would freeze up. Internet connection lost. 

While I treasure the periods of truly reliable high-speed service I have, the periods of downtime are becoming more and more common. One interesting note is that I live with a roommate, who doesn't report any internet problems at all.

A call to Comcast was of very little help; they checked the modem and said "you have a constant connection of high speed, unbelievably fast". They recommended it was either my computer or wireless router, so I began to troubleshoot them:

1. I cleared my entire computer of spyware using Lavasoft's Adaware. I have Norton Antivirus 2007, loaded with latest virus definitions. Did a full system scan, found nothing. No viruses, no spyware, and I even cleared up some space on my C drive and defragged. Even after all of this, my web browsers will take 30 to 45 seconds to load simple pages, the progress bar will just "hang" for what seems forever. Of course, the pictures will never load, and sometimes the connection times out. Page cannot be found.

2. I connected a cable directly from the modem to my laptop, bypassing the wireless router. Still, the same problems persist.

Can anyone begin to point me in the right direction? What is going on here? Comcast says everything is fine, my roommate is reporting no problems , and my computer has been completely cleared of spyware and checked for viruses. (And, if my computer was the problem, then why would I have periods of blazing fast internet between the sluggish periods?)

Please help! Keep in mind I have a somewhat limited understanding of networking. Thanks


----------



## hermes (Aug 12, 2000)

its definitely not something your flatmate is running hogging bandwidth?


----------



## TerryNet (Mar 23, 2005)

Since you get the same problems wired or wireless and the other computer doesn't experience the problems that certainly points to your computer or what hermes suggested.

If you think Norton AV and Ad-Aware are going to detect all malware you are more than a little bit too optimistic. Tests that PC World magazine runs at least annually show no product (and they no longer rate Ad-Aware near the top) getting anywhere near all Spyware or Adware.

When the slowdowns occur do you use Task Manager (or anything else) to determine if there are any uploads going on? Or some process using a lot of CPU?


----------



## hermes (Aug 12, 2000)

The things i know that cause these symptoms, are P2P or A N Other on the other PC - I am currently at an ISP and honestly, 90% of dsl outages and network slowdowns, after sometimes exhausting investigation, are user initiated. 

A poor isp infrastructure - We left carphone warehouse in the uk because of exactly these symptoms, and no discernible cause. ISP's often role out expansions and new services without the necessary infrastructure to back it up. It may not involve your service but still impact it.


----------



## JohnWill (Oct 19, 2002)

You might queue up a few line quality tests at www.dslreports.com and when you catch it being slow during the test, post the results here. We should be able to determine if it's your ISP or something within your network.


----------



## Mtrpls (May 26, 2003)

Hey everyone,

Thanks for your help so far, but the problem still persists. I decided to load a webpage today that contained over 100 images; the page took a long time to load. Just before I loaded the page, I fired up Windows Task Manager to check the progress. As you can see, the page loaded rapidly for about 30 seconds, then everything slowed down for about 30 to 45 seconds where nothing would load. Then it would pick up again, then cut out.


----------



## Mtrpls (May 26, 2003)

I connected through my wireless router, but I'm somewhat confused as to how to read these results. The percentages listed on the left under Wireless Network Connection... are they the total capacity of the router? If so, why did they never go up above 12.5%?

Additionally, under the LinkSpeed column, the speed in Mbps is always changing. Sometimes I can get 54 Mbps, other times it will drop to 36, sometimes it will dip down into the 20s... What does this mean?


----------



## TerryNet (Mar 23, 2005)

In my experience when your nominal wireless bandwidth (54Mbps, 36Mbps, etc.) is fluctuating either you do not have the correct driver (especially if it is an Intel!) or you have wireless interference.

For an integrated wireless adapter check for the latest driver on the web site of the manufacturer of your laptop.


----------



## JohnWill (Oct 19, 2002)

That reading isn't going to tell you much. Did you try the line quality tests I mentioned?


----------

