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Broadband: Is my cable connection becoming saturated?

by Lee Koo (ADMIN) CNET staff/forum admin / September 18, 2009 6:49 AM PDT

Broadband: Is my cable connection becoming saturated?

It has been several years since I got my cable modem. Living
in what was a relatively sparsely populated area, I enjoyed
lightning-fast response times on the Internet. My son grew up
and got involved in online shoot'em-up gaming and
downloading, and I detected that when he was doing that, the
little activity light on the modem was on a lot more than
off, which was expected.

More recently, I have noticed that the activity light is
nearly always on, blinking off occasionally and my response
lags a bit. I can't blame my son's activities anymore, since
he went off to college, and his PC's been powered off. What
could possibly be the culprit? Is it time to complain to my
ISP? Thanks for your opinions!

--Submitted Steve B.

Here below are some featured member answers to get you
started, but please read all the advice and suggestions
that our members have contributed to this question.

Broadband connection --Submitted by GEO2003

Testing your Cable modem upload/download speed --Submitted by ralphjramirez

Cable broadband slow down --Submitted by Zouch

Sounds like a virus... --Submitted by darrenforster99

Is my cable connection saturated? Not likely... --Submitted by Watzman

Please read more contributions below in this discussion thread.

If have any additional advice or experience to share with Steve, click on the reply link and submit it away. Please be as detailed as possible when providing a solution. Thank you!
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Trojan bot?
by fivecentfamily / September 18, 2009 9:52 AM PDT

What you describe sounds like you might have a Trojan program running on your computer, and it is phoning home for instructions and possibly sending itself out to other systems, generating spam emails, or who knows what else.

I would run Hijack This! and post the report to a website forum where people skilled in these things can comment on it, and let you know if you have any questionable processes running on your PC, and how to get rid of them.

You also might want to call up your provider and see if they can tell you your usage info for the past few months. That COULD give you a clue as to when things started to get busy, and what is going on.

If you are using an excessive amount of bandwidth, your cable company can up your bill or take other actions against you if you are exceeding the limits laid out in the company's acceptable use policy. So it's good to have an idea of how much bandwidth you are using.

Good luck to you.

~Ken Nichols

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Has the original submitter responded??
by Glenn51 / October 4, 2009 7:51 PM PDT
In reply to: Trojan bot?

Lee: has the person who posed the question responded back as to if their problem has been cured?? I see as I'm replying that at least 90+ people have replied to the original question and the replies are still coming in. It would be nice to see if any of the solutions have done the trick!
Most all replies, as even my own, fall into 2 categories:
1) virus, trojan, spyware
2) theft of service( someone using his modem for their own)
Just curious!

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You still can go online?
by umarzuki / September 18, 2009 9:58 AM PDT

If you're not, it is time. It is suppose to blink every 3 seconds or so, otherwise it means there's something funky is going on at ISP site (their router or something). You have to put up with their customer service usual troubleshooting routine like:
Try to on the modem for x seconds, then on the modem
If failed they will try to reset connection, sometimes work
If failed they will ask your IP, netmask, and gateway then lodge a report. Be sure to bug them every hour.

This is based on my experience with TM.

Hope this helps.

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Is my cable connection saturated? Not likely ...
by Watzman / September 18, 2009 9:58 AM PDT

It's very unlikely that your cable modem connection is saturated.

Cable modems and routers both fail. And, unfortunately, the most common failure modes are not "hard" failures (e.g. they don't work) but failures that result in flakey and "degraded" service.

I'd replace your cable modem and/or router. The cable modem presumably comes from the cable company. I just replaced mine yesterday because our system had gotten "unreliable and slow" (BUT HAD NOT "FAILED"). And the cable modem was indeed the problem. In most places, you unplug the cable modem & power adapter, take them to a counter at some cable company office, and they swap it on the spot. Sometimes they prefer or require that you first have contacted their tech support (I didn't do this, but they do prefer it. Cable company tech support CAN run diagnostics and see internal modem statistics that you can't, so it's not an unreasonable request).

If swapping the cable modem doesn't fix it, try a new router (note: EVERYONE should be using a router for security reason even if you only have a single computer to connect to the internet. The only exception would be if your cable modem has an internal router with NAT (most cable modems do not). You want your computer's IP address to be "private" and not "public" (Private IP addresses almost always start with 192.168.{whatever}.{whatever}).

FWIW, in my experience, the average life of a cable modem or router before it gets "flakey" is about 1 to 2 years. I think that a lot of the problems are thermal, these things are not well ventilated and many of them give off a LOT of heat and get terribly hot inside and basically, over time, they "cook" themselves.

It's also possible that you have some malware installed that spending a lot of time sending some identity thief information about what's on your computer and what you are doing. You need on the computer a software Firewall, Anti-Virus software and anti-"malware" software. My recommendation at this time is Norton Internet Security (covers the first two) and Windows Defender.

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Hope you use a UPS
by glen271 / October 4, 2009 1:26 PM PDT

I'm sure you know that the best thing for electronic equipment is a UPS- couldn't recommend this more. As someone who works for tech support that supplies replacement routers, I have encountered customers who go through modems/routers rather quickly and are very displeased at the poor life span of their equipment. I believe that most of the cases are caused by an electrical problem. They are using no surge protection, a poor surge protector/ UPS, or a surge protector/ UPS that has gone bad/been damaged. (I ought to work for APC sales.)


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Always use an UPS
by pogo943 / October 31, 2009 1:29 AM PDT
In reply to: Hope you use a UPS

I am agreeing with the above answer completely. I had my cable modem on UPS (like all of my computer equipment)for the last 12 years and never had a problem, however I replaced it because of getting a faster connection from Charter my cable provider. It did speed up my overall performance, however what really sent it flying was what Charter called a "power boost" and sent me this information on Wed of this week.

To use it, I simply had to shut down my modem Motorola SB 5101 for 30 seconds and restart it. I could immediately see the difference in uploading and downloading video of all types. Noticeably, my movie streaming from Netflix. I really recommend it. I am running Windows XP Sp-3 as well as Tiger 11xx and I really saw my uploads to my MAC web page soar.

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Activity light on cable modem when not in use!!
by mjd420nova / September 18, 2009 9:59 AM PDT

This smacks of a virus or spyware that has infested your PC. Maybe your machine has been turned into a BOT. If you are not using the internet and the activity light on your cable modem is on, maybe you have a WIFI router that your neighbor has decided to use, otherwise you need to check your PC. Bring up the Task Manager and check the precesses tab to see what process is using CPU cycles to find out where this activity is coming from. Also check out the NETWORK tab to see any activity generated by you PC on the network. Hope you find the problem.

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do this: They will soon move on to the next free meal
by dps782 / October 3, 2009 12:52 AM PDT

I?m only addressing ?the neighbor (or someone) has gained accessed to your wireless? portion.

Mine slowed drastically and I did the usual routine of things trying to figure it out with no luck and thought hmmm,,, just maybe my IP has been accessed and that?s what is slowing me down?

What I did has literally solved the problem. If you are lucky, your access is being used by some savvy IP thief.

Do this:
For a week or two, simply unplug the main incoming Internet line from the modem for a couple of nights a week and/or during the day. Mix up the unplugging times so that if someone is using your IP wireless they find it to be very unstable and better yet, aggravating to use. They will soon move on to the next free IP meal leaving yours alone and back up to speed.

Sounds simply but if your problem is from illegal access this worked for me.

Good luck!

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why not set up wep or wpa
by reffu42 / October 3, 2009 1:19 AM PDT

why bother unplugging your router when you can just set up a secure connection so they can't access your router

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An even simpler way is to...
by crt167gc / October 3, 2009 2:35 AM PDT

...turn off the broadcast of your router's SSID. You can do this thru your browser to access the router's admin screens.

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Hiding/Changing the SSID Make Wireless Secure
by dps782 / October 3, 2009 2:50 AM PDT
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"secure" is not invincible
by dps782 / October 3, 2009 2:39 AM PDT

Thanks, we have always used a secure WPA2-PSK. I have since learned that "secure" is not invincible and found the above mentioned tactic to have worked. Was it a chance happening? I don?t know. I do know that I have not had a problem since. No doubt I?m calling in the cyber-demons with that bold statement but wanted to share my thoughts and hope it comes in useful. Have a safe weekend.

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For Total Security - Hardcode Your Machine's MAC Addresses
by studmoose / October 3, 2009 6:55 AM PDT

Broadcasting your SSID does very little in exposing your network. If you hide your SSID, those who want to hack into your network -- the real PC guys -- can find this information out very easily.

The use of WPA & WEP security is fine, thouse some at work are able to break these encryptions in 5-20 minutes with special software running on a laptop, so that only offers moderate security.

The best way to secure your network is to use high encryption while also configuring your router to only allow predefined MAC addresses. Since the MAC addresses identify your individual machine's COM cards, this is the best way to prevent others from hacking into your wireless network. Of course, anyone visiting your house would have to get their MAC address added into the router before they could use it.

But, do you want a secure network or a flexible one?

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WPA2-PSK has never been cracked...
by JCitizen / October 3, 2009 1:53 PM PDT

You had something else as a problem, they may have used spyware to determine you key, or your key was non-existent or too weak. A weak key can be cracked in seconds with a dictionary attack.

If they are this sophisticated, even script kiddies can spoof you MAC address. Besides they already know it, so that is redundant.

Quite frankly the first thing I do to a customer's PC when they are having connection problems and security isn't the fix; is use CCleaner to clean all the junk out of the PC. This clears up the page downloads immediately.

I run Vista x64 and it doesn't like misbehaving cookies, so I install Adaware Anniversary Edition with AdWatch enabled, and voila! No more connection problems for a LONG time.

You do have to update it, run CCleaner and Adaware scanning once and a while though!

Personally I buy the lifetime protection of MBAM and I have the fastest downloads of my life! When I clean with CCleaner there isn't as much to clean, but I now wait too long to do that too! I rarely have problems, so I now forget to keep up the maintenance!!

I do not work for any man or company; I just hate malware to pieces!

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Search 'hack WPA2-PSK'
by studmoose / October 4, 2009 1:13 AM PDT

There are dozens of video HowTo's on how to do it.

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Any poorly configured security can be cracked...
by JCitizen / October 4, 2009 6:45 AM PDT
In reply to: Search 'hack WPA2-PSK'

I'm talking about the encryption. If you have a poorly configured security and/or a weak passphrase to the key, then yes, you might be able to extract it from a special sniffer and use highspeed computing to crack the key.

The goal is to put a good key in that would keep the bad guys guessing for a couple of years. There are also web-sites that you can test your password to the key, to see how long it would take to crack using the best current technology.

As far as WPA2 this site is a good example:

Member parrotheadmjb had this to say:

"I hate to say it, but im pretty confident that this is fake, i tested (under the presumption it was fake) and it generated the same key as the one in the video, not only was the key the same, but EVERY LINE in terminal was the same that appeared in the video. even if it did "crack" the packet and gave you this "key" it would be useless since you have to inject packets into the router to hack a wep encryption, the ipod touch does not have the hardware, or ability to perform the required injection, rendering this useless. I still have no idea why someone would go through the trouble of writing a fake script to run in installer and post a video of it on youtube.

Even if wep was possible, wpa-psk or wpa2-psk would be IMPOSSIBLE to perform on the ipod touch, i have heard people talk about vulnerabilities of tkip in wpa-psk but wether or not you can hack it, is unknown to me, but the cpu, etc required to hack wpa-psk is far more than the touch can provide. wpa2-psk is out of the question, it implements the far more secure AES encryption, your computer cant do it - your touch definitely cant, unless you run a password "cracking" software to use dictionary attacks, brute force, etc."

This is pretty much the case everywhere using other hardware. Now if you have a pretty good passphrase, it would take some heavy duty equipment to crack that, unless your hardware wireless device has a circuit vulnerability. That is not the fault of the encryption protocol, but the wireless device.

I've tested the WPA2-PSK on my clients and it would usually take 11 years to crack the average good paasphrase used by my clients. Now as computing power goes up, the likely hood WPA becomes obsolete, also goes up. But you got to balance this with the fact that some people don't live in crowded areas and would find out the cracker in a heart beat! Plus, the majority of my clients don't have either service or personal information worth going to that much trouble to gain.

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Sniff it to see if it smells bad.
by throuwlin / October 4, 2009 11:37 PM PDT

When I had a cable modem, I had a simular issue. It turns out that there had been an outage in another area and the cable company bridged the two network segments together. When I noticed that my modem activity light was lit most of the time I though "OMG I've been hacked!!!". So I loaded up ethereal"now wire shark" and sniffed the traffic to see what was going into and out of my computer and what ports were being used to do so. To my surprise 80% of the traffic was ARP(Address resolution Protocol) request. There were so many people on the segment that the router could not keep track of where everyone was. so is was constantly asking for addresses. It's like mail call with the letters mixed up. The router will yell out an IP address and computer was yell back here. As you can imagine hat amount of latency this would add if every time the router send you a piece of information it needed to ask where you were first and then wait for a reply.

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For sure!..Man those situations can be a mess!....
by JCitizen / October 5, 2009 11:15 AM PDT

Wire shark is a very valuable pen-test tool.

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Broadband speed
by sirpaul1 / September 18, 2009 10:07 AM PDT

I bet your 'sparsely' populated area is hardly that anymore. Cable broadband is based on a 'hub' theory. The more users on the 'hub', the slower the internet is for everyone.

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Sounds like malware to me...
by Doh_1 / September 18, 2009 10:08 AM PDT

If you're seeing lots of network activity that you can't explain, then I'd guess that one or more computers in your house that are connected to your cable modem most likely has a virus and/or malware running on it. I guess I'd just go through the virus and malware/spyware detection procedures, running antivirus and anti-malware programs on your computers. For example, you could go to and run their online virus/malware scan, that's a good cross-check for your current antivirus software. There are other online scans that are available as well. There's also various other scans that you can run, I'd look around for the latest in that area. Worst case, you've acquired a rootkit or have multiple viruses and malware and will need to re-install, but that's often not necessary, viruses and malware can be removed usually.

One particular caution though, don't assume that using "system restore" can restore you to a clean system...well-written viruses and malware will also get into your system restore area and contaminate that. If you get to the point where you can't remove the viruses/malware, it's time to think about re-installing, not using system restore. In fact, most of the virus and malware removal toolkits tell you to turn off system restore before proceeding with removing a virus.


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usability lag
by tedtks / September 18, 2009 10:10 AM PDT

when Clearwire came to town it was amazeingly fast. we were useing
cable from the cable tv company and had many problems with their modems going out.
its a small town - 22,000. and after a year the signal started to
drop now and then. then it got worse at specific times of the
day. everyday.
they didnt install enough equipment to handle the growth in useage.
I will gladely go back to the tv modem or dsl (if I can get it).
every afternoon after school gets out usage drops to the point of
a simple screen refresh takes 5 min. and fri nights, saturdays, are
slow. the rest of the time its back to lightening speed - almost.
sometimes when it should be clear its not. so I unplug the receiver and the wireless units - count to 20 and plug them back in and the
resetting clears it up pretty good.

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Sounds like your computer is now a robot
by willgen / September 18, 2009 10:11 AM PDT

My best guess is that your computer has become infected with a robot program that is using it to blast either spam, malware, or both, out to the rest of the internet.

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Broadband speed #2
by sirpaul1 / September 18, 2009 10:13 AM PDT

If you're wireless; and not locked down, you may be getting a lot of freeloaders.

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remember party lines?
by harryjmorgan / September 18, 2009 10:28 AM PDT

In fact Steve, YES, your "party line" has grown from when you first hooked up. That has always been the big difference between cable broadband and DSL from the phone company. The more subscribers on the wire from your cable provider, the more bandwidth absorbed or shared by all. In DSL from the phone company, only you are on your line so all of the bandwidth is yours alone, much like the old party lines as opposed to a private line. Think of five, ten or fifteen people sharing as opposed to just one using your PC or printer, that's the effect even if cable says their bandwidth is greater than the phone companies.

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by GEO2003 / September 18, 2009 10:53 AM PDT

Hello Steve,

Some cable providers will offer you assistance in running a virus/trojan/bot scan if you don't know how.

However, it is very likely that if you call customer service they will first ask you questions such as :
1-Have you try a reset of the Cable Modem.
2-Do you have a Wireless Router connected to the Modem and have you try to reset that to defaults. ( You did not mentioned if you have one on your Post ).

From your post you said that your Son's pc is off, so that means that you are using a different pc/laptop.

A Wireless Router will constantly keep a live connection with your modem.

I think most Wireless Routers now a days have a feature that allows the Router to connect to the manufacturers website to locate updated FirmWare, if your Wireless Router received an automatic upate, it may have created a connection problem between the Router and the Cable Modem.

If you have a Wireless Router and if you are familiar with the settings you might want to try and reset it so that it makes a new connection with the Modem.

The Wireless Router is assigned an IP address from the Cable Modem or ISP if you will, but resetting the Router does not necessarily release the OLD IP address. Going into the Wireless Router Control Panel and Releasing and Renewing the IP address could give you a new connection to the ISP's Servers.

The moral of the story here is - Start with the simple things, such as re-setting the Cable and if you have one - The Wireless Router.

You can download Antimalware programs from Cnet/download or you can go to and download their portable utilities to check your computer for Malware.

I recommend Avast because it is easy to use and very accurate.

And once you have done this few things, you can call your service provider. and won't have to spent a lot of time going through these scenarious with them since you have already checked them off the list.

If they can't help you over the phone - assuming you end up with a connection issue rather then anything else, make an apointment for them to change your Cable Modem.


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Speed varies depending the time of use
by uvinod / October 3, 2009 5:44 PM PDT

My optimum online connection used be close to 15 mbps at any time of the day. Recently, the speed goes down to about 5 or 6 mbps en early evening and becomes 14 o 15 mbps late at night.

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re: activity
by grumble / September 18, 2009 10:55 AM PDT

Could be your PC is infected and is being used to send spam.

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Testing your Cable modem upload/download spped
by ralphjramirez / September 18, 2009 11:14 AM PDT

Before contacting your ISP check the speed of your connection with one of those free online speed checks. I had a problem with slow upload/download spped so I ran that speed checker, and presented this info to my ISP (Comcast). They sent a technician out the next day and found that the modem I had was not capable of handling the higher speeds that Comcast not provides. They swapped out my modem and WOW what a difference. I don't use my PC for gaming but do upload/download large image files that are super fast.

This is the link to the Line speed tester I use:

Hope this helps..............Ralph

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by leehemen / October 3, 2009 2:44 AM PDT

DO NOT use it! It is a scam, AGAIN, by Uniblue to sell their garbage. If you want to buy it, go ahead but do not think you are getting something for free.

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Speed Test SCAM...
by Good-PC.Guy! / October 3, 2009 11:59 AM PDT

Little doubt! ...
Cuz there's all sorts of such false tests & checks to be found on the!
Most just want to pull something else on you while you're trying their claimed offers, etc.!
I guess ya just have to develop the knack of being able to tell the 2% of good/true stuff from the 98% of pure junk.

CHANCES ARE THAT WHAT YOU FIND (especially that which you had not approved), WILL SOME DAY BE IDENTIFIED AS SOME SORT OF MALWARE (by at least one of your anti-malware programs).

BE SMART... BE CAREFUL (on the net)!

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