Phone line quality testing

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dkaleta
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Joined: Mon Feb 18, 2002 1:01 am
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Phone line quality testing

Post by dkaleta » Wed Sep 04, 2002 5:44 am

Hi,<p>I was wondering if anyone knows how to test phone line quality using a modem. Some DSL companies provide a program that tests phone line quality for DSL usage. I want to be able to go one of my modems to another of my modems to test the quality. Any help would be great!

billdar
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Re: Phone line quality testing

Post by billdar » Wed Sep 04, 2002 9:05 am

DSL companies send packets across the line, increasing the transmission speed until an unacceptable percentage of packets are lost.<p>Ive done the same sort of tests with UARTS and IR transcievers. Increasing the baud rate until transmittion fails.<p>The quality of the line effects the maximum transmittion speed by inducing skew and attenuation on the signals. You can think of skew as the "tilt" of a signal that is changing much slower than it should. Attenuation is the loss of voltage or current due to the line itself.<p>Knowing this, there are many variables with testing your home phone line quality. They include the jack itself, jack to house wireing, house wiringing to house box, house box to phone company central office and many switches in between.<p>The best way to test it would be using a network analyser and getting the signal to noise ratio. Or even a little occiliscope to see the jitter while you are on the phone. <p>Given thats a silly idea, the only other way I can think of is using two modems in the same house. Have one call the other, and keep increasing the connection speed until it won't connect any higher. (you must check the actual speed it connected at after the handshake) Then try connecting to your ISP and do the same.<p>Hopefully calling yourself takes a shorter transmission path than calling your ISP.<p>
-Bill<p>Then again... I might not know what I am talking about, I sure couldn't spell it.<p>[ September 04, 2002: Message edited by: billdar ]</p>

N8ZUX
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Re: Phone line quality testing

Post by N8ZUX » Sun Sep 08, 2002 7:50 pm

<blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr>Originally posted by D. Kaleta:
Hi,<p>I was wondering if anyone knows how to test phone line quality using a modem. Some DSL companies provide a program that tests phone line quality for DSL usage. I want to be able to go one of my modems to another of my modems to test the quality. Any help would be great!<hr></blockquote><p>I play with Telcom stuff, few things to look at ..<p>1) are you using DSL or Dial up ?<p>2) City or Rural location<p>3) are you on Copper ( Old , older than dirt, or fiber optic cable ( BIG WISH for me :-) )<p>Dial up under Ameritech land has alot of old older than dirt stuff reason is even GTE / Verizion discovery of same color older than dirt wiring, only discovered by an accidental trench dig a cable gets cut and the techs discover that they have a problem, also I have placed service calls to find lines have green stuff on copper called corrosion, simple fix.<p>also everyone look at that nice Gold plated jacks if noise is present my TELCOM friend told me moisture corrodes the Jack & Modular ( green stuff ) moisture from kitchens, and cats who mark their territory unless they get a sudden 90 volt ringer up a place they get a weird look :eek:
I find this every so often especially humidity areas we have that in Michigan jacks are cheap, so is 2 pair Telcom wire unless you are doing Cat 3 or CAT 5 ( Cash Register Rings $$$$$$ ) :confused: Good Luck !!!
Mark N8ZUX
Radio is my hobby

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