| Author |
Message |
rh128592
Guest
|
 Posted:
Sun Dec 19, 2004 2:40 am Post subject:
Cat5 568B cable wrong... but right. Huh? |
|
|
Explain this and I'll send you some Christmas cookies...
I have a OEM cat5 cable. On the side it says "EIA-568B".
You and I know that, at the very least, pins 1,2 and 3,6 should match
up. You and I also know what 568B says the wiring order needs to be:
white orange/orange
white green/blue
white blue/green
white brown/brown
But this OEM cable is wired...
white orange/orange
white green/white blue
green/blue
white brown/brown
Here's the kicker: the OEM cable works. From the cable modem to the
router it works. From my laptop NIC to the router it also works. But
the pins don't match: 1,2 ... 3,5 ... 4,6, ... 7,8
In short, I must have some bad info somewhere. I should be happy it
works but I want to understand why this "wrong" cable is working.
Cheers,
Brian |
|
| Back to top |
|
 |
David Lesher
Guest
|
| Posted:
Sun Dec 19, 2004 2:40 am Post subject:
Re: Cat5 568B cable wrong... but right. Huh? |
|
|
"rh128592" <rh128592@yahoo.com> writes:
| Quote: | Explain this and I'll send you some Christmas cookies...
I have a OEM cat5 cable. On the side it says "EIA-568B".
You and I know that, at the very least, pins 1,2 and 3,6 should match
up. You and I also know what 568B says the wiring order needs to be:
white orange/orange
white green/blue
white blue/green
white brown/brown
|
| Quote: | But this OEM cable is wired...
white orange/orange
white green/white blue
green/blue
white brown/brown
|
If I follow you; then this is wrong.
1 w/or
2 or/w
3 w/gn
4 bl/w
5 w/bl
6 gn/w
7 w/bn
8 bn/w
is from the chart...
| Quote: | Here's the kicker: the OEM cable works.
|
No mystery. On a short cable, in good circumstances; almost anything
works. It's when you have 100 meters, colo with adjacent cables.
slightly kinked, etc. that the spec is vital.
| Quote: | In short, I must have some bad info somewhere. I should be happy it
works but I want to understand why this "wrong" cable is working...
|
Because the Ethernet receiver is able to hear the far end bits even
in the face of local interference. In short, you lucked out.
--
A host is a host from coast to coast.................wb8foz@nrk.com
& no one will talk to a host that's close........[v].(301) 56-LINUX
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433 |
|
| Back to top |
|
|
Robert Redelmeier
Guest
|
| Posted:
Sun Dec 19, 2004 3:25 am Post subject:
Re: Cat5 568B cable wrong... but right. Huh? |
|
|
rh128592 <rh128592@yahoo.com> wrote:
| Quote: | white orange/orange
white green/white blue
green/blue
white brown/brown
|
OK. So one pair is split, if you can tell the wh-gr from wh-bl.
| Quote: | Here's the kicker: the OEM cable works. From the cable modem
to the router it works. From my laptop NIC to the router it
also works. But the pins don't match: 1,2 ... 3,5 ... 4,6,
... 7,8
|
Not at all surprising from the modem to the router, since
this is short and 10baseT. NIC to router is a bit more
surprising because this usually runs at 100baseTX, but
it may still work for a short cable.
-- Robert |
|
| Back to top |
|
|
James Knott
Guest
|
| Posted:
Sun Dec 19, 2004 8:59 pm Post subject:
Re: Cat5 568B cable wrong... but right. Huh? |
|
|
rh128592 wrote:
| Quote: | Here's the kicker: the OEM cable works. From the cable modem to the
router it works. From my laptop NIC to the router it also works. But
the pins don't match: 1,2 ... 3,5 ... 4,6, ... 7,8
|
It might work for short distance, but not long. It doesn't matter what the
colours are, provided proper pairing is maintained. However, good practice
dictates using EIA/TIA 568A or B. Chuck that cable and get a good one.
Cables are cheap. |
|
| Back to top |
|
|
Guest
|
| Posted:
Tue Dec 21, 2004 6:39 pm Post subject:
Re: Cat5 568B cable wrong... but right. Huh? |
|
|
EIA/TIA 568B is a standard not a pin out. T568A and T568B are pin out.
That cable is just saying in meets the EIA/TIA standards. The T is
important people! |
|
| Back to top |
|
|
rh128592
Guest
|
| Posted:
Thu Dec 23, 2004 3:13 pm Post subject:
Re: Cat5 568B cable wrong... but right. Huh? |
|
|
Thanks all. Good to know. I just learned how little I know. And
supposedly I'm the family computer "expert".
Cheers,
Brian |
|
| Back to top |
|
|
|
|
|
|
FAQ
Memberlist
Register
Profile
Log in to check your private messages
Log in