Using the Centillion EtherSpeedII Switch Modules

Pin 1 crosses to pin 3, and pin 2 crosses to pin 6. To build this cable, you must cross pairs. The pairs are listed in Table B-4, with an example of the color combinations found in two typical cables.

Table B-4.

Pairs in an RJ-45 Crossover Cable

 

 

 

Pairs

Example 1

Example 2

Color Combinations

Color Combinations

 

 

 

 

1 and 2

Orange/white and white/orange

Orange and blue

3 and 6

Green/white and white/green

Yellow and black

4 and 5

Blue/white and white/blue

Red and green

7 and 8

Brown/white and white/brown

Brown and gray

 

 

 

Using Category 5 Unshielded Twisted Pair Cables

Unshielded twisted pair (UTP) cable is the recommended wiring option for 100BASE-TX Fast Ethernet, as specified in the IEEE 802.3 standard for Ethernet. Fast Ethernet recommended UTP cable consists of four pairs of twisted insulated copper conductors bound in a single plastic sheath. The 100BASE-TX Fast Ethernet transmissions are implemented through two-pair or four-pair Category 5 UTP wiring using standard shielded RJ-45 connectors. Category 5 cable is certified to handle up to 100 MHz bandwidth. The EIA/TIA T568A standard recommends the installation of Category 5 UTP cable for 100 Mb/s networks.

Use the following guidelines to ensure that your cables perform to specifications:

Certification—Make sure that your Category 5 UTP cable has completed the Underwriters Laboratories (UL) or Electronic Testing Laboratories (ETL) certification process.

Terminating method—To minimize crosstalk noise, maintain the twist ratio of the cable up to the point of termination (untwist at any termination should not exceed 0.5 in.).

Pairing options—For optimal performance from your cable plant, use the EIA-T568A Commercial Building Wiring Standard pairing option at each end of the cable. The terminating hardware offered by most major manufacturers is correctly color-coded for proper wire placement according to that standard.

B-6

207344-B

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Nortel Networks 207344-B manual Using Category 5 Unshielded Twisted Pair Cables