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Cat5 cable pairs for telephone
Name: coal miner Date: July 24, 2003 at 21:35:53 Pacific OS: 98se CPU/Ram: p4/256 mb
Comment:
Is there any problems using the 2 unused cable pairs in a cat 5 cable for telephone service. I need a 2 line phone near a computer and do not have any extra cable run for a telephone. I need a phone for the computer at times and I do not like going wireless due to range and privacy issues
Name: FredF Date: July 24, 2003 at 21:59:10 Pacific
Reply:
No problem unless you plan on going to gigabit which uses all four pairs.
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Response Number 2
Name: anonproxy Date: July 24, 2003 at 22:02:34 Pacific
Reply:
Perhaps you have heard of those ethernet networks over your home phone line? This is the physical layer of the Internet (OSI model).
Cat5 is better telephone cable (different connections of course, same twisted pair concept).
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Response Number 3
Name: coal miner Date: July 24, 2003 at 22:05:13 Pacific
Reply:
adding to my orig post. Will the 90 vac ringing voltage from the phone cause interference on the 2 pairs used for the ethernet. i understand that the ethernet voltage is only around 15 volts and I am worried out the 90vac ringing voltage being induced into the ethernet pairs. Will the twist of the cat5e cable prevent this.
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Response Number 4
Name: anonproxy Date: July 24, 2003 at 22:53:17 Pacific
Reply:
"Will the twist of the cat5e cable prevent this?"
That is the reason the cables are twisted - crosstalk works against itself. If something affects all wires equally, there is no asynchronous loss.
It's all mathematical really.
If x=1, then x-1=1-1. Well, maybe I should have started with x=2 instead...
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Response Number 5
Name: FredF Date: July 24, 2003 at 22:54:12 Pacific
Reply:
No problem - lots of companies used to run a single cat 5 to each desk and combine phone & network. Your ethernet connection needs pins 1 & 2 as a pair and 3 & 6 as a pair - the other two pairs can be phone.
Summary: It is not recommended to combine LAN and telephone wiring into one cable. Some of the reasons have been given earlier in this thread. Previously some people used a method to do it but have abandoned t...
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