568A/B vs my way

Aviator19 · 06-20-2008, 01:27 PM

I was wondering if there was any particular reason one wire pair is separated while all the other pairs remain together at the ends.

Example:

green stripe, green. orange stripe, blue, blue stripe, orange, brown stripe, brown

vs

green stripe, green, orange stripe, orange, blue stripe, blue, brown stripe brown.

I have just been keeping the wire pairs in order on both ends as I crimped them. Then today I found what the standareds where, and only half of the wires are actually not used. Are there any situations where all 8 wires are used?

Haven't really had any networking problems since all the wires are "straight through".

Just trying to learn more as I go.

Thanks

matt261102 · 06-21-2008, 04:18 AM

Once you need a cross over cable one of the ends must have the pinouts changed. You need to arrange so 1 goes to 3 and 2 goes to 6.

Although this can be done using any order with the wires, the TIA/EIA cabling standards just make it easier.

The standard 10/100 LAN connections only use 2 pairs, but gigabit connections will use all 4.

johnwill · 06-21-2008, 05:09 PM

Well, if you don't have the pair on 1-2 and 3-6 properly wired, the cable will most certainly give you problems, especially if it's longer then a few feet. I've seen lots of wiring like this after a new installation is done, and in every case, I've had to rewire the connections correctly.

Aviator19 · 06-30-2008, 03:51 PM

I was wondering why though. That alright, I think I found the answer:

The wire pairs are twisted together to shield themselves from interference and to keep the signal loss from reducing. They form like a coil I guess. Since the - and + pins are not together you have to still use that one wire pair so the signal remains strong.

The first replier answered the other question though at the end...

So I don't need a Cat5e cable for a Gb/s net, just any line with all 8 wires?

Thanks for the answers!

johnwill · 07-03-2008, 04:21 PM

No, you actually need CAT5e or CAT6 for gigabit, "any line with 8 wires" won't get it done. The impedance of Ethernet cable is specifically matched to the Ethernet NIC.

06-20-2008, 01:27 PM	#1 (permalink)
Aviator19 Registered User Join Date: Dec 2006 Location: Hemet, CA, USA Posts: 48 OS: Windows XP SP2 (32 bit, or 64 bit) My System	568A/B vs my way I was wondering if there was any particular reason one wire pair is separated while all the other pairs remain together at the ends. Example: green stripe, green. orange stripe, blue, blue stripe, orange, brown stripe, brown vs green stripe, green, orange stripe, orange, blue stripe, blue, brown stripe brown. I have just been keeping the wire pairs in order on both ends as I crimped them. Then today I found what the standareds where, and only half of the wires are actually not used. Are there any situations where all 8 wires are used? Haven't really had any networking problems since all the wires are "straight through". Just trying to learn more as I go. Thanks

06-21-2008, 04:18 AM	#2 (permalink)
matt261102 Registered User Join Date: Jun 2008 Location: Melbourne, Australia Posts: 133 OS: XP SP2, Server2003, Fedora 7	Re: 568A/B vs my way Once you need a cross over cable one of the ends must have the pinouts changed. You need to arrange so 1 goes to 3 and 2 goes to 6. Although this can be done using any order with the wires, the TIA/EIA cabling standards just make it easier. The standard 10/100 LAN connections only use 2 pairs, but gigabit connections will use all 4.

06-21-2008, 05:09 PM	#3 (permalink)
johnwill Manager, Networking Forums Join Date: Sep 2002 Location: S.E. Pennsylvania, US Posts: 31,468 OS: XP-Pro, Vista, Linux Blog Entries: 1	Re: 568A/B vs my way Well, if you don't have the pair on 1-2 and 3-6 properly wired, the cable will most certainly give you problems, especially if it's longer then a few feet. I've seen lots of wiring like this after a new installation is done, and in every case, I've had to rewire the connections correctly. __________________ If TSF has helped you, Tell us about it! or Donate to help keep the site up! Microsoft MVP - Windows Desktop Experience

06-30-2008, 03:51 PM	#4 (permalink)
Aviator19 Registered User Join Date: Dec 2006 Location: Hemet, CA, USA Posts: 48 OS: Windows XP SP2 (32 bit, or 64 bit) My System	Re: 568A/B vs my way I was wondering why though. That alright, I think I found the answer: The wire pairs are twisted together to shield themselves from interference and to keep the signal loss from reducing. They form like a coil I guess. Since the - and + pins are not together you have to still use that one wire pair so the signal remains strong. The first replier answered the other question though at the end... So I don't need a Cat5e cable for a Gb/s net, just any line with all 8 wires? Thanks for the answers!

07-03-2008, 04:21 PM	#5 (permalink)
johnwill Manager, Networking Forums Join Date: Sep 2002 Location: S.E. Pennsylvania, US Posts: 31,468 OS: XP-Pro, Vista, Linux Blog Entries: 1	Re: 568A/B vs my way No, you actually need CAT5e or CAT6 for gigabit, "any line with 8 wires" won't get it done. The impedance of Ethernet cable is specifically matched to the Ethernet NIC. __________________ If TSF has helped you, Tell us about it! or Donate to help keep the site up! Microsoft MVP - Windows Desktop Experience