Non EIA/TIA cable 2

[iolair]

We have some cable runs that were not wired using the EIA/TIA standards. What I found was that the pinouts were right, but the cable colors were wrong. In other words, pin 1 went to pin 1, pin 2 to pin 2, etc. What they did, though was make the cable so that pins 1&2 were the orange pair, pins 3&4 were the blue pair, pins 5&6 were the brown pair, and pins 7&8 were the green pair. The cables work fine with a hub at 10Mbps, but won't work with a switch at 100 Mbps. Is the reason the speed, the twists, or the switch? This particular building is only 15 workstations, so re-wiring can be done. Cat5 was used. Thanks.

Iolair MacWalter
Network Engineer

 

[MasterRacker]

Looks to me like you have split pairs. 3&6 are supposed to be a pair and 4&5 are a pair. High speed won't work if the pairing isn't correct.

Do you have enough service loop to reterminate? That would be a lot cheaper than a full rewiring.

Jeff
[small][purple]It's never too early to begin preparing for [/purple]International Talk Like a Pirate Day
"The software I buy sucks, The software I write sucks. It's time to give up and have a beer..." - Me[/small]

 

[iolair]

Split pairs - haven't heard that before. Yes, that's right, they wired it so that 3&4 are a pair and 5&6 are a pair.

Yes, I do have enough to reterminate, and that's what I'll do. Thanks for the info.

Once again, Tek-Tips saves me headaches. Thanks, MasterRacker.

Iolair MacWalter
Network Engineer

 

[iolair]

One more stupid question. I got most of the cabling re-terminated. There are a couple that I haven't traced yet. Is it possible to configure the Cisco Switch to 10mbps and half-duplex on those cables and have it work? It's a 3550XL.

Thanks again.

Iolair MacWalter
Network Engineer

 

[NECPBXtech30]

it should work as long as pins 1+2 and 3+6 are straight through from the patch panel to the jack. i would definetly change it the first chance you get though.

"However beautiful the strategy, you should occasionally look at the results." Sir Winston Churchill

 

[iolair]

Yes, as soon as I find where they go, I'll fix them. Thanks!

Iolair MacWalter
Network Engineer