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8. Out of curiousity...·What does a node look like?
·What is that weird cylinder thing they put on my splitter?
·How is my modem working at -18db if it's supposed to be at least -15?
·Do you get better connection closer to the node?
·Is there a optimal range for the receive window?
·Do I need a surge protector for my cable modem?
·Sharing bandwidth - how many users per node?
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Well, not all of them will look the same, but here in Gainesville, if the node is on the ground, it's hidden inside this:
See the second box in the background? That one contains the battery backup for the node. I didn't have a chance to take pictures of the batteries, but just imagine 4 or 5 car batteries inside that box and that's kind of what it looks like. ;)
This is the inside of the node box:
This is a picture of a node that TACSPEED posted in the forums a few weeks ago:
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by Raydr 
last modified: 2002-11-06 01:13:16 |
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That's a filter.
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by Raydr
last modified: 2004-03-26 11:13:06 |
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As far as the -15 to +15 range goes, that's not actually mandatory for the modem to work. It's the ideal range, because in most cases, at -15 the noise is starting to get bad.
Here's an analogy:
Say you're in a filled room having a conversation with someone. The volume they are speaking at will be the signal level. The volume of the people around you is the noise level.
Now, if the person speaking to you is at a low volume, you're going to have a hard time making out what they're saying because of all the noise.
HOWEVER, remove that noise from around you, and you can hear that guy just fine. If you have very little noise, you can operate at lower signal levels reliably.
I've had a modem running at -32db before, because it was running through a 300MHz splitter.
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by Raydr |
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I think there is a Node at the pole in my back yard. Do you get better results the closer you are to the node?
Not necessarily. The farther away you are, there is a greater chance of noise getting into the line, but the difference in speed is quite negligible, especially since the LEs (Line Extenders, or amplifiers) boost signal both ways all the way down the line.
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by nwilcox edited by ergibbs
last modified: 2003-04-17 09:07:49 |
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Yes, there is an optimal range for every class and type of service, every operating system, etc.
Go here:
»/tweaks/
Thanks to StillLearn for pointing out a spelling mistake.
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by Raydr
last modified: 2005-05-17 10:13:59 |
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You can never have too much protection. Lightning can enter your home through your cable lines just as easily as the phone/electric lines. Of course, the NEC requires that we ground the line to prevent lightning damage, but that does not guarantee that lightning will not enter your home.
I recommend a surge protector for your cable modem if you're in an area with lightning storms (especially in the south). Make sure you get one that is cable modem compatible.
A surge protector shouldn't affect bandwidth. From what I've found, it will either work or it won't. Make sure you use a surge protector that is rated for cable and/or DSL modems.
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by gahan edited by ergibbs
last modified: 2003-08-18 13:31:39 |
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Check out this FAQ for a detailed description
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by StillLearn edited by ergibbs
last modified: 2003-08-18 13:24:09 |
