Cable Modem Troubleshooting
For several years now, I have been dealing with ongoing reliability issues with my cable Internet at home. It’s been sufficiently unreliable to notice, but not sufficiently unreliable to distract me from my infinite “MUST DO” list. We’re talking once every other day, I’ll notice that the connection will drop for about 30-45 seconds. Most of the time, I just refresh the browser and continue along my merry way.
My wife does not share this tolerance. She absolutely hates when a site she’s researching doesn’t load. The swirly browser “I’m thinking” icon sits there, taunting her, mocking her, bringing out the most vile of phrases from her mouth. If I were the Internet, I’d be hiding under the bed. For serious.
OK, not really that bad. But she’s quite vocal when it happens. I finally decided to do something about it.
Step 1 - Call Comcast. The friendly technician explained that the status information she was getting from the cable modem pointed toward a bad connection between the modem and the wireless router I used. Two possibilities there… bad router, or bad cable. I had already recently upgraded from an aging Linksys WRT54G to a D-Link DIR-655 Extreme N Wireless Router, so I more or less ruled that out. Cable? Easy enough to swap. Net result? No noticeable problems for a few days, then back to the same routine.
Step 2 - I swapped out the D-Link router for an Apple AirPort Extreme not too much later (not in an attempt to resolve this issue, but for research purposes). Problem stayed. This prompted me to explore further.
Step 3 – Question the wiring leading up to the cable modem. Took a gander in the basement. Can you spot the problem?
That’s an 8-way passive splitter. Each channel being attenuated by -11dB. That works out to each cable coming out of the splitter having less than 8% of the power of the signal that went in to the splitter. This has been this way since I bought the house, and never really paid attention to how the incoming lines were split.
I put a cheap $10 RadioShack 2-way passive splitter (each channel attenuated by -3.5dB, losing roughly 50% of the original signal strength) in front of the 8-way. One of those 2-channels heads straight to the office, the other into the 8-way to be distributed throughout the house.
The result? Too early to tell for reliability. BUT… I happened to run a speed test before and after the modification.
Cable Modem Speed with 8-way Splitter
Cable Modem Speed with 2-way Splitter
That’s an order of magnitude increase in upload speed. Boo-ya-ka-sha.
A. Callum, 
Jeff L and one other person are discussing.
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[...] Standing On The Brink » Blog Archive » Cable Modem Troubleshooting http://www.standingonthebrink.com/index.php/cable-modem-troubleshooting – view page – cached For several years now, I have been dealing with ongoing reliability issues with my cable Internet at home. It’s been sufficiently unreliable to notice, but not sufficiently unreliable to distract… (Read more)For several years now, I have been dealing with ongoing reliability issues with my cable Internet at home. It’s been sufficiently unreliable to notice, but not sufficiently unreliable to distract me from my infinite “MUST DO” list. We’re talking once every other day, I’ll notice that the connection will drop for about 30-45 seconds. Most of the time, I just refresh the browser and continue along my merry way. (Read less) — From the page [...]
Jeff L 7:24 pm on October 13, 2009 Permalink |
I had a similar problem at my last house. My splitter was set up the same way. Unfortunately, the problems only started after we had a lighting strike in the neighborhood. Comcast guy came out, took a look at the splitter, and basically did the same thing you did. Problems went away immediately.
I am amazed at your upload speed difference, though!
A. Callum 4:16 pm on April 26, 2010 Permalink |
I still see Four potential problem with the connection,
My speed test
Download speed 21.28 Mbps
Upload speed 2.56 Mbps
Binho 7:01 pm on October 13, 2010 Permalink |
you need to know exact how much signal you have coming out of the main cable, if you have a lot of signal, you need a splitter to reduce the signal(like the 8 way)Replace that 2way, and the 8 way to a 3 way that have a lost of 7db, that’s a good rule of thumb if you don’t have a meter to see how much of signal you have, second, don’t use anything from radio shark or anything that is “gold” they are good for analog signal but as soon as you put in w a reverse path, it looks like it works but not really. i was a service tech for about 10 years working for comcast, and we see this problems all the time. check my eBay store and you will see what kind splitter im talking about.
i hope this help