Cabling Devices
Media Requirements
Incorrect cabling is often the cause of network configuration problems. Read the next two pages if you’re unsure of your requirements.
100Base-TX
The 100Base-TX Fast Ethernet specification requires that you use
CAT 5 UTP cabling to operate at 100Mbps. If you use lower grade cabling (CAT 3 or CAT 4), you may get a connection, but will soon experience data loss or slow performance. You’re limited to 100 meters between any two devices.
10Base-T
The 10Base-T Ethernet specification allows you to use CAT 3, CAT 4, or CAT 5 UTP cabling. You’re limited to 100 meters between any two devices.
Straight-through vs. Crossover Cables
Hub ports are wired MDI-X, so use a straight-through cable when connecting to a workstation or server (network adapter cards are wired MDI). For direct connection to another MDI-X port, use the daisy-chain port or a crossover cable. Here are the pin arrangements for the hub’s Ethernet jack and the typical RJ-45 connector.
Pin 8 | | | Pin 1 | 8 |
| 1 | 2 | |
| | 1 |
| | | |
| | | | Clip |
Pin 1 | 9 | 10 | Pin 8 | |
Testing a cable
A quick way to check a cable’s link integrity is to plug one end into the daisy-chain port, the other end of into port 2, and check the Activity LEDs for ports 1 and 2. If the LEDs are on, you have a functioning straight- through cable.
If the LEDs are off, remove the cable from the daisy-chain port and reinsert it in port 1. If the Activity LEDs for ports 1 and 2 are on, you have a functioning crossover cable.
