InteropNET NOC Team
Just wrapped up #interop with @DynInc powering DNS for the NOC. Already have ideas for going bigger and better for next year!
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Cory von Wallenstein
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Cory von Wallenstein
10Base-T as a Bottleneck?
A few weeks ago, I grew extremely frustrated with my cable modem connection dropping out on occasion, and revisited the cable splitting approach to some success. However, something didn’t seem right about the speed test I was getting. I’ve been perfectly happy getting download speeds on the order of 5-7 Mb, and upload speeds on the order of 1 Mb.
With all of the hulabaloo on faster home Internet connections lead by the marketing giants at Comcast and Verizon, it left me wondering…
Could I squeeze out more from my home Internet connection?
A look on the back of my aging Toshiba cable modem gave me hope:
That’s a 10Base-T Ethernet interface from the cable modem to the home gateway (currently an Apple AirPort Extreme). Everything else in the home is Gigabit wiring, except for this one link between the home gateway and the cable modem. Could it be that this 10Base-T interface was now my bottleneck in Internet connection speed?
I upgraded to a Motorola SB6120 (with a Gigabit Ethernet interface to my home gateway), and put the unit to the usual speed test.
And check out the result:
That’s an improvement from 8Mb down to 29Mb down, and from 2Mb up to 8 Mb up. WOW! I was honestly shocked that the home network has now outgrown 10Base-T.
Financially, this was actually fortuitous timing; I had recently noticed on my cable modem bill that we were leasing our cable at a cost of $3 per month, and this was increasing to $5 per month in November 2009. Rather than start paying $60 per year to lease the modem, I simply shelled out $85 to buy the new Motorola SB6120 cable modem outright.
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Cory von Wallenstein
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.
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Jeff L
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A. Callum
I still see Four potential problem with the connection,
My speed testDownload speed 21.28 Mbps
Upload speed 2.56 Mbps -
Binho
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
A. Callum, 
Jeff L and one other person are discussing. 
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!