Help with networking using pre-existing Cat-5e.

[TwstdVTECSol816]

First post.

Im networking a friend of mine's house and when they built it (Summer 02), they put in Cat-5e for the phone lines. I plan on hooking up a router (Linksys BEFSR41) and cable modem where the lines (4 total) enter the house. I already made the connectors on one end but when I opened up the phone jacks for each room, the installers cut off 3-4 inches of insulation (ive read that this is usually done for voice transmission). The wires are also untwisted about an inch or two from the end (again, for phone lines). I tried pulling on the cable to see if I can start from where the insulation begins but it didnt budge. We want this to be as clean as possible. That's why we're using the Cat-5e thats already installed. Ive read on some other forum that the installers were supposed to have left a maintenance loop of maybe 18". In this case, they didnt.

What do you suggest I do? Should he call the General Contractor or the company that wired the house and make them redo it? Thanks for any help you can give me.

 

[franklin97355]

pre-existing what? if there is a conduit then it would probably be the best route. If no conduit then you can run the cable any way that is convienient, in the attic, basement, or crawl space.

 

[TwstdVTECSol816]

Pre-existing cable. I dont know if there is any conduit inside the walls or not. Johnson Nguyen
Email - jnguyen@feltycc.net
AIM - TwstdVTECSol816

 

[franklin97355]

try this site

http://www.arstechnica.com/guide/networking/installation-1.html

 

[TwstdVTECSol816]

Thanks for the link. Johnson Nguyen
Email - jnguyen@feltycc.net
AIM - TwstdVTECSol816

 

[daronwilson]

That is an interesting link. Be very carefull what you do, that installation wouldnt pass a Cat5 certification. Also I'm not sure why you would waste a whole closet to house what would do nice in an OnQ (or similar) panel. There are some good basic ideas....geez I should really write something like that with more accuracy. Whatever you do, DON'T terminate the way he has illustrated but pulling back the jacket and untwisting the pairs. If you cut the hole in the wall with a jigsaw, you'll likely scratch up the paint around it too, use a drywall saw. The lathe and plaster illustration is a common problem on older houses when one tries the jigsaw approach.

It is a good start for an article on doing the connectivity your self, but it is a bit misleading on the terminations.

In a nutshell though, you will be fishing new wires up (or down) the wall, no need to remove or touch the existing stuff. There is only so much guidance one can offer, unless you have done retrofit/remodel stuff it just takes some practice. With existing boxes, I usually holesaw a hole in the bottom (top) of the box, stick a 36" flexible shaft drill bit in there, and drill down into the basement to get your wire.

Good Luck!

It is only my opinion, based on my experience and education...I am always willing to learn, educate me!
Daron J. Wilson, RCDD
daron.wilson@lhmorris.com

 

[TwstdVTECSol816]

Is there anyway to edit what I write? I posted my response without looking at the link first. The way my friends house is made, the rooms sit on top of the garage so I dont know how to fish from there. Its not just up and down, its sideways and across. I dont think he wants to cut anything right now. We'll try to see what we can do though.

Another thing I have to say. This forum rocks! I didnt expect to get this many replies in so little time. Johnson Nguyen
Email - jnguyen@feltycc.net
AIM - TwstdVTECSol816

 

[jeffmoss26]

Daron-I have been to the link above before. I believe the author corrected himself and wrote "you should really terminate this way (being the correct way, not exposing the wires), not how I did it" but was too lazy to post pictures of the right way. jeff moss
jeffmoss26@adelphia.net

 

[Bobg1]

Good grief.
I took a look at that link and if there is a mess to happen that is it.
Please I hope no one will do as bad of a job as that site shows.

 

[sunco]

even though the insulation is removed and the wire is untwisted if the wiring scheme is correct 568a or 568b you will still be able to get a 100 base t connection.

 

[daronwilson]

Well, you might get a 100 base T connection, and then again, you might not. Why would you want to do it wrong and risk it?

Put simply, there is a reason that the standards require twist and tight termination. In the old 10bT days, we didn't care much about twist, or termination, it ran pretty much on whatever we threw at it. 100bT is a bit more picky. It needs the twist and it likes the impedance of the wire to be constant. When you remove the jacket of the wire and let the pairs get away from each other, you change that characteristic impedance. Likewise, when you untwist the wires in excess of 1/2" before the termination, you change the characteristics of the channel and risk a reduction in data throughput. How much degradation will the channel take before it has errors? Who knows, hence the reason we terminate it to specific standards so we know there is some headroom in the channel bandwidth, thus allowing the planned data throughput to be achieved with some margin.

Yes you might get an LED to come on and say 100bT, and yes you might even make it run at that speed, and it is also likely that you will experience problems.



It is only my opinion, based on my experience and education...I am always willing to learn, educate me!
Daron J. Wilson, RCDD
daron.wilson@lhmorris.com