Length phone cord/connection quality

[A31Chris]

How much does the length of the phone cord coming out of the wall when using dial-up modems affect transmission quality, speed, pings etc? I have like, 10ft of cord between me and the wall. I heard it should be kept under 3 feet. Is this true?

[Platypus]

When your phone cord connects into the wall socket, behind it there is ... more phone cord! So it's not really the length of cord in the room so much as the quality of it and the quality of the connections where it plugs in. Data transmission problems occur mostly due to noise (commonly bad connections) or signal reflections from changes to the impedance characteristic of the line (also can come from bad connections, or different quality of cable). So a 3' poor quality cable in the room could cause more problem than a 10' good quality one. The only way to be sure would be to compare some cables with each other, I have observed slight variation between connection speeds using different cords.

[Topdog]

Gotta agree with Platypus. What's 20, 30 or even 100 metres on the end of kilometres of telco street cable. What is more important is the quality and condition of any joints or connectors in the line.

[J A L]

hello,

Platypus is right on target! There is one thing you might want to consider though for best modem cables.

RFI (Radio Freaquency Interference) is what happens when you get a Antenna effect from running two wires side by side. Back in the old days when you bought a stereo it came with a thick clear plastic coated wires that were parallel to each other about 3/8's of a inch apart. You hooked these two wires up to the antenna positions on the back of your stereo. This was your antenna.

When you have a phone line the wires often times are parallel and it raelly doesn't make that much difference when it comes to using it for a phone because any RFI it may receive is in a bandwidth outside the frequency of normal phone reception and therefore is never heard by the phone equiptment. Since Voice communication uses so little of the the bandwith available by the copper wire it is really of no consequence. But your modem on the other hand is slightly affected by RFI as to how much bandwidth the phone lines will be able to carry.

So to get the very most from your phone line... you want to use a twisted phone wire. Two wires twisted is not a antenna but two wires parallel is!! Now they make this twisted wire in big spools so you can rewire your house and they also make phone cables with the RJ11 jacks on them, in various lengths already twisted. Personally I would try the premade ones and see how they go. I would use your connection speeds to determine if you would benifit from rewiring one modem wall jack. Even though you may get no improvement it still may keep your modem from handshaking down to a slower speed by keeping a cleaner connection. Most modems will not speed up when the line gets clearer they only slow down a bit or maintain the same connection over time. US Robotics Courier Modems are the only modems I know of that will speed up when line conditions improve! If your using twisted wires I would say there is no limit on length inside your house for phone lines! Well your house isn't a mile long is it?

[Eeyore]

Another consideration is the number of phones connected. If house wiring branches out to each room, those other phones are on line while the computer is. If the computer is close to the in line, you could route all other phones through the computer's telephone out (if your modem has one). Another method, which I had my kid employ, was a relay that cut off all other lines except that to the computer when on line. This gave him a higher connection speed.

------------------
My
Two Cents
Dennis
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[Junker]

I have made it a rule of mine that the computer is always the FIRST thing on the line...

[NoBoB]

The vast majority of "silver satin"-- the flat cable between the walljack and the device -- is straight, not twisted, while the vast majority of the wiring between the jack and the Central Office is twisted pairs. In theory, this makes the silver satin considerably more prone to picking up noise and other interference, because it does not have the inherent noise canceling capabilities of the twisted conductors.

Whether this can be extrapolated to "3 feet is better than 10", I don't really know, but I kinda doubt it, unless you drape the extra 7 feet over a transformer or something

[Nix]

Well our PC used to be in a room at the other end of the house using a 10M cordto the nearest phone jack and achieved average connection speed 37,666bps.

When me move it to the other end of the house so the connection cord is now 10cm the average connection speed is 37,666bps.

So for my mind, no difference and I think it is all the cable and connections between me and my ISP that makes the difference.