• Status: Solved
  • Priority: Medium
  • Security: Public
  • Views: 305
  • Last Modified:

Strange CAT5 cabling

Hey guys,

I saw this strange issue where a number of cables had been made and the wiring is unlike I have ever seen in all my time.

It is supposed to be a straight through cable and is seemingly working on server - switch communications. However, the green and blue pairs are switched.

It looks like this.

END A
1. orange/white
2. orange
3. green/white
4. blue
5. blue/white
6 green
7. brown/white
8. brown

END B
1. orange/white
2. orange
3. blue/white
4. green
5. green/white
6. blue
7. brown/white
8. brown

Now I know END A is your standard 568-B standard. But I have never seen END B before. It certainly isn't 568-A.
0
Gareth Gudger
Asked:
Gareth Gudger
  • 2
  • 2
2 Solutions
 
David L. HansenProgrammer AnalystCommented:
It's not a cross-over cable, nor is it a regular pinout.  Sometimes people will only need a couple pairs (like with phone) and they don't want to leave the other pairs out.  So you could end up with something like this, but only (I believe) if they didn't need all the pairs for their purposes.
0
 
Darr247Commented:
Maybe the terminator has a blue-green vision deficiency anomaly?
Or they just got mixed up.

The cable won't work wired like that, unless Auto-MDIX on both ends manages to straighten it out somehow.
0
 
Gareth GudgerAuthor Commented:
That's what I am figuring. It is a server or PC on one end. But the Cisco Catalyst does support Auto-MDIX.
0
 
Darr247Commented:
I've never seen a gigabit port/adapter that didn't support Auto-MDIX... I'm just not sure all Auto-MDIX impementations can do more than make a crossover cable into a straight through cable and vice-versa.
0
 
Gareth GudgerAuthor Commented:
The mystery continues. I guess we will never know. Thanks for helping guys!
0

Featured Post

Keep up with what's happening at Experts Exchange!

Sign up to receive Decoded, a new monthly digest with product updates, feature release info, continuing education opportunities, and more.

  • 2
  • 2
Tackle projects and never again get stuck behind a technical roadblock.
Join Now