Cabling

Hi everyone,

Yesterday I connected 3 pc on an Ethernet LAN. 2 are running Windows XP and 1 Linux as the gateway to Internet. The LAN is private network. The 3 comps have DLink PCI cards connected to a switch through a straight through cable. Everything is working.

But, the cable ends RJ 45 have been color coded in a different manner to what has been shown in this website in Cabling tutorials. The way I have connected is. Pair 2(orange), Pair 1(Blue), Pair 3(Green) and then Pair 4(Brown). which is differnet from Pair 3(Green), Orange with strip, Pair 1(Blue), Orange and Pair 4(Brown).

How come Im still able to have the network working wven with a differnent color code. Is it OK if I continue or do I have to change it to the one shown in Straight Though Cable Tutorial page.

Also I did the cross over cable as shown in the Cross over tutorial page, for connecting two computers, it is working fine. I tested this by transfering a 400MB file from 1 comp to another. The speed I obtained was 10mbps. (it took 40 seconds). Is this the correct speed or is there a way I can improve it further.

Another question. I ran Samba on Linux and I was able to see the computer from XP machine through Network Neighbourhood and then clicking computers near me. So I want to know how to display computer in my network in Linux gui window.

Hmm the way I see it, if everything is working fine, theres no problem. There are actually two colour codes for the cables I think.

If your network cards are 10mbps then you're getting the right throughput. Sounds just fine to me.

The colors don't matter. The ones that are on the website are the standard way and the way you would typically see them if you buy them from the store ready made.

You actually could do them straight through the way you have them and it would work, but you might have problems with cross talk or in a bad area. What you have done is separate your twisted pairs. The twists are what keep your line clean and prevent cross talk. Your like colors (orange/orange with white stripe, for example), are always twisted. This is why you see the solid green wire over on 6.

In ethernet you use only 1,2,3 and 6. It is important to use the same color pairs on 1 and 2 while another pair is on 3 and 6 (it doesn't matter which color or which one is stripped. It is best to use them as Chris has laid out as that is the way the industry does it.

There is nothing more wrong than the statement color does not matter. And "well it works" does not make it right. Because the minute you try to upgrade to 100MBps you will experience problems. Specifications are made for good reasons. If you plan on NEVER expanding or upgrading you network don't bother to fix it. However, how often is this the case?

At least qualify that as long as you don't split your pairs color really doesn’t matter. Also be aware EIA/TIA standards are different from old phone wire standards and the wire colors retain their pair number no matter what pins you put them in. They are not based on position in the connector.

I looked at your web pages on UTP straight and x-over. Looks like real accurate information. I suggest you stand by it.

Just a little history, the 568B standard for straight through cables is predominate because it matches AT&T standards for UTP CAT 5 network cabling. There are organizations (with sizable networks) that have gone with 568A as the standard for their straight through cables. You might note that a crossover is simple using a 568A on one end and 568B on the other.

Also, Be aware that there are network-cabling contractors that will use the 568A standard unless the 568B is specified. Enough ranting, I'm sorry but it's my many years of experience in electronics and familiarity with crosstalk vs. frequency, as well as NEXT, FEXT, attenuation, impedance, skew, etc. But more recently just the shear volume of poorly made connections with RJ45 connectors on CAT 5e UTP cable that I have found by net workers that were never properly trained in cabling. I'm talking about networks in commercial buildings like Hospitals and Schools. By the way the Hospital did redo training and cabling and is now in compliance with a very professional job.