Cross/straight?

can anybody tell me what the difference is between an cross and a straight utp-line?
and wich sort is the best to use on a switch.

tnx, robert

The utp cable is a cable of 8 wires each protected from each other , coming together in a special connector , the RJ-45 connector.

Sometimes this connector is also known as a 8P8C connector (8 ports of which are 8 connected).

A cross utp… otherwise known as a cross-over cable has some wires switched one ONE end. (Since a UTP cable has two RJ-45 connectors attached , you need to make the “switch” in wires on only one of these ends). Technical speaking you’re then connecting the Tx to the Rx

Schematic :

With that cable you can connect two UTP NIC’s (Network Interface Card) together. You don’t need a hub or a switch.

A straight line utp is used to connect a NIC with a hub or switch.

Schematic :

The switch or hub does all the work distributing the data across all other UTP cables and thus NIC’s and thus computers. (Your situation).


If you want to connect more than 2 computers , use straight lines and a hub or switch.

If you not ever going to have more than 2 computers , use a cross-over utp cable.

If however you think there might be more computers in the future… stick to straight cables and a hub or switch.


P.S.

You might find that you don’t actually need to connect pins 4 ,5 , 7 and 8 at all since they have no function at all.Source of the EIA/TIA T568A standard.

But i recommend using them anyway , because there’s nothing that bad as a loose wire next to IT equipment. And who knows , someday the standards will advance and you need them anyway.

P.P.S

ISDN cable is NOT , i repeat … NOT UTP cable ! Use only CAT5 (or CAT6) cable !

[semi-off topic]

applauds
have you written a book before ?
i rekon you would be good at it.

Originally posted by Huzzy
[semi-off topic]
applauds
have you written a book before ?
i reckon you would be good at it.

Credits for the pictures go to their appropriate websites of course :slight_smile:

It’s my job to search for the complete specs of newly introduced (IT) products in our medical systems. And that needs a lot of searching for approvals. You tend to understand the basis of websites and Google very quickly that way :slight_smile:

Some of these approvals are Underwriters Laboratories , FDA and a lot of other stuff. Basically the UL and FDA marks are the most standard found (check your mouse for instance for the cULus mark).

Bad thing is that i have to make a lot of reports about it (and since managers can’t read , i sometimes add pictures).

Fun thing is i get to test if all that equipment really approves (putting 2 kilovolts on it , drop it from a certain height , etc).

Originally posted by Mr. Belvedere
Picture 1:

Picture 2:

Picture 3:

Mr. Belvedere, I think your pin order is wrong. In picture 1, the pin order should be from right to left, not left to right, in other words, pin 1 should be at the rightmost and pin 8 leftmost. You can take any good Cat 5 cable and see what I mean. Another good source is:
http://www.aptcommunications.com/ncode.htm

I’m just pointing this out, because I found this forum page on Google, and it can be misleading to others, since it is partially wrong. Perhaps you could edit the picture(s)? Thanks.

Originally posted by AstroNox
[B]Mr. Belvedere, I think your pin order is wrong. In picture 1, the pin order should be from right to left, not left to right, in other words, pin 1 should be at the rightmost and pin 8 leftmost. You can take any good Cat 5 cable and see what I mean. Another good source is:
http://www.aptcommunications.com/ncode.htm

I’m just pointing this out, because I found this forum page on Google, and it can be misleading to others, since it is partially wrong. Perhaps you could edit the picture(s)? Thanks. [/B]

I think that it all depends on the picture. If it is a picture of the cable, then yes, it is backwards. But if it is a picture of the female end (the network card or hub/switch) then it is correct.

I also agree with Mr. B in that you should use ALL wires within the cable so that future improvements/standards will not be a problem. My boss is colorblind, so he takes the two sets of wires that he can distinguish the best and uses them for 1 2 3 and 6. I normally make the cables so that all wires are being used.

Good luck.

If you plan to use your network cables for GBit lan someday, you really should go for the 8-wired setup, as GBit lan needs it. For 100mbit you can do 4 wires just fine, as long as you know what you’re doing :wink:

Thanks xtremeskier97. I didn’t think of it that way first, thanks for pointing it out. Thus, I said it was a little misleading, I think it is more appropriate if the pictures are more related to each other, like, jack and jack or port and port, instead of showing a port and a jack… You get what I mean?

Peace, and God bless.

W00t… a year old thread still in Google and my name’s on it ? :bigsmile:

Thans for making my day a bright one , but i’m not gonna edit the picture. It’s still correct considering the T568B setup.

Why i don’t use the T568A setup ?

Easy :

The T-568A specification reverses the orange and green connections, so that the blue and orange pairs are on the center 4 pins, which makes it more compatible with the telco voice connections

That’s all good , but when i make an Ethernet connection , i don’t want it to be compatible with anything , except Ethernet itself.
I’ve seen many other uses for CAT5/6 UTP cables, where it shouldn’t be. People using them as telephone lines (wich require 2 cables in the Netherlands) , wrong ISDN setups , etc. I’ve seen ISDN centers going up in smoke because of it.

It is correct yes, but misleading thats all :wink:

Oh yes I forgot, it came up as the first entry when I typed “Cross Straight Cable” in Google. That’s why I pointed it out. :slight_smile:

In fact I signed up just to point this out. :expressionless:

But you people are cool anyway ^^. :smiley:

Originally posted by AstroNox
It is correct yes, but misleading thats all :wink:

No problemo , together we tell everybody the how and why of UTP. :bow:

Originally posted by AstroNox
Oh yes I forgot, it came up as the first entry when I typed “Cross Straight Cable” in Google. That’s why I pointed it out. :slight_smile:

Damn… cdfreaks forum is getting GOOD !! :bigsmile:

Okay , enough off topic mumbo jumbo… let’s continue this in the living room if we want to… ok ?