LinuxQuestions.org
Review your favorite Linux distribution.
Go Back   LinuxQuestions.org > Forums > Linux Forums > Linux - Hardware
User Name
Password
Linux - Hardware This forum is for Hardware issues.
Having trouble installing a piece of hardware? Want to know if that peripheral is compatible with Linux?

Notices


Reply
  Search this Thread
Old 01-08-2012, 07:58 AM   #1
Skyer
Member
 
Registered: Aug 2011
Posts: 113

Rep: Reputation: 6
How/Why there are 4 twisted pairs in UTP/STP


Hello,
I'm sorry in advance for such a newbie question, but I'd like to know more about how networks work physically, and came to this question.

In some older materials I have, there are UTP cables shown and described. They contain two twister pairs on for sending and one for recieving.

However, RJ-45 connector has 8 pins, and cables used with it have 4 twisted pairs. Now I've heard the method used to trasmit signal is called differential signaling, but I don't know anything else about it.

Would anyone mind to elaborate, and post why is better to have 4 twisted pairs there, how does the method work, etc.?


Thanks,

Skyer
 
Old 01-08-2012, 08:24 AM   #2
onebuck
Moderator
 
Registered: Jan 2005
Location: Midwest USA, Central Illinois
Distribution: SlackwareŽ
Posts: 13,006
Blog Entries: 28

Rep: Reputation: 2266Reputation: 2266Reputation: 2266Reputation: 2266Reputation: 2266Reputation: 2266Reputation: 2266Reputation: 2266Reputation: 2266Reputation: 2266Reputation: 2266
Member response

Hi,
Look at 'Ethernet over twisted pair';
Quote:
Some of the specified characteristics are attenuation, characteristic impedance, timing jitter, propagation delay, and several types of noise. Cable testers are widely available to check these parameters to determine if a cable can be used with 10BASE-T. These characteristics are expected to be met by 100 meters of 24-gauge unshielded twisted-pair cable. However, with high quality cabling, cable runs of 150 meters or longer are often obtained and are considered viable by most technicians familiar with the 10BASE-T specification.
Definitions from the above should provide enough information to aid in understanding. Twisted pairs are used to reduce signal noise from EMI due to the noise canceling effect of the pairs.

Look at differential signaling to get a basic understanding. This Transmission/Receiver technique has been around long before Ethernet.
HTH!
 
Old 01-08-2012, 08:29 AM   #3
Skyer
Member
 
Registered: Aug 2011
Posts: 113

Original Poster
Rep: Reputation: 6
Thank you, I'll check it. The biggest part of the problem, I guess, is the language barrier .


Skyer

Last edited by Skyer; 01-08-2012 at 08:34 AM.
 
Old 01-08-2012, 08:37 AM   #4
onebuck
Moderator
 
Registered: Jan 2005
Location: Midwest USA, Central Illinois
Distribution: SlackwareŽ
Posts: 13,006
Blog Entries: 28

Rep: Reputation: 2266Reputation: 2266Reputation: 2266Reputation: 2266Reputation: 2266Reputation: 2266Reputation: 2266Reputation: 2266Reputation: 2266Reputation: 2266Reputation: 2266
Member response

Hi,
Quote:
Originally Posted by Skyer View Post
Thank you, I'll check it. The biggest part of problem, I guess, is the language barrier .

Skyer
If you have a problem or question then feel free to query. Basic understanding for signal transmission/reception for UTP is not that difficult. Yes, the semantics can be difficult but most of the content is linked to expand your understanding.
If it is a linguistics barrier then we will still be glad to help where we can.
 
1 members found this post helpful.
Old 01-08-2012, 10:18 AM   #5
Skyer
Member
 
Registered: Aug 2011
Posts: 113

Original Poster
Rep: Reputation: 6
Alright,
seems like I've found what I needed. I'll go through the materials you've posted - and hope you don't mind me asking question, eventually.


Skyer
 
Old 01-08-2012, 10:27 AM   #6
onebuck
Moderator
 
Registered: Jan 2005
Location: Midwest USA, Central Illinois
Distribution: SlackwareŽ
Posts: 13,006
Blog Entries: 28

Rep: Reputation: 2266Reputation: 2266Reputation: 2266Reputation: 2266Reputation: 2266Reputation: 2266Reputation: 2266Reputation: 2266Reputation: 2266Reputation: 2266Reputation: 2266
Member response

Hi,

Quote:
Originally Posted by Skyer View Post
Alright,
seems like I've found what I needed. I'll go through the materials you've posted - and hope you don't mind me asking question, eventually.


Skyer
Fire away!

If I cannot answer then I am sure that we can figure things out somehow.
Or someone else here on LQ can augment any findings or questions.
 
  


Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off



Similar Threads
Thread Thread Starter Forum Replies Last Post
Cat 6 UTP and the outdoors metallica1973 Linux - Networking 11 08-28-2008 07:22 PM
STP loops eth777 Linux - Networking 3 10-31-2007 07:52 AM
what are *.stp files? irfanhab Programming 1 10-03-2006 10:37 PM
about UTP cat5e kpachopoulos General 2 02-23-2006 01:57 PM
UTP Cat5 spaceballs Linux - Networking 2 03-30-2005 02:36 PM

LinuxQuestions.org > Forums > Linux Forums > Linux - Hardware

All times are GMT -5. The time now is 02:33 PM.

Main Menu
Advertisement
My LQ
Write for LQ
LinuxQuestions.org is looking for people interested in writing Editorials, Articles, Reviews, and more. If you'd like to contribute content, let us know.
Main Menu
Syndicate
RSS1  Latest Threads
RSS1  LQ News
Twitter: @linuxquestions
Facebook: linuxquestions Google+: linuxquestions
Open Source Consulting | Domain Registration