Specifications

DocSTAR Level 2 Service Training Workbook Page 33
most commonly used type of twisted-pair cable. In fact, it is the most popular type of LAN
cabling in use today. The difference between STP and UTP is in the transmission
distances. Since STP is shielded it can carry a signal for longer distances. UTP cable
can carry a signal for 100 meters (328 feet). There are different categories of UTP cable:
Category 1 or Cat 1 – Traditional phone cable that can carry voice but not data.
Category 2 or Cat 2 – Certifies UTP cable for data transmission rates up to 4Mbps.
Category 3 or Cat 3 – Certifies UTP cable for data transmission rates up to 10Mbps.
Category 4 or Cat 4 – Certifies UTP cable for data transmission rates up to 16Mbps.
Category 5 or Cat 5 – Certifies UTP cable for data transmission rates up to 100Mbps.
The connector used for UTP cable is the RJ45 8-pin connector. See Figure 3.6.
Figure 3.6 UTP & STP cable design & RJ45 connector
At this time category 5 twisted pair cable is the most commonly installed network cable,
due to its capability to transmit data at 100Mbps. If you will be creating your own network
cable, verify that it is category 5 cable and you MUST use the following wiring diagram for
attaching the connectors on both ends of a Straight-through patch cable:
In cases where you would need to communicate from one PC to another PC or network
device directly without going through a hub or switch, you will need a Crossover cable.
To create a Crossover cable, you MUST wire one end as outlined above and the other
end as follows: