1. Describe the three most common types of cabling media used in LANs.
Coaxial Cable. Coaxial cable comes in two versions: Thinnet and Thicknet. Thinnet looks like regular TV cable.* It is about 1/4 inch in diameter and is very flexible and easy to work with. In contrast, Thicknet is about 1/2 inch in diameter and not very flexible. Thicknet is older and not very common anymore except as a backbone within and between buildings. Coax transmits at 10 Mbps..
Twisted Pair. Twisted pair looks like telephone wire and consists of insulated strands of copper wire twisted together. There are two versions of twisted pair cable: Shielded Twisted Pair (STP) and Unshielded Twisted Pair (UTP). STP is commonly used in Token Ring networks and UTP in Ethernet networks where it is referred to as "10baseT." Transmission rates vary between 10-100 Mbps..
Fiber-Optic Cable. Fiber-optic cable consists of a thin cylinder of glass surrounded by glass cladding, encased in protective outer sheath. Fiber-optic cable is very fast (100 Mbps). It can transmit over long distances (2 km +) but is expensive.
*Don’t confuse Thinnet cable (RG 58) with cable TV cable (RG 59). They look alike but they are not interchangeable.
2. What are the recommended maximum segment lengths for each type of cable?
The type of cable plays a role in how fast a signal will degrade as it is transmitted. The following are the recommended maximum cable lengths:
Thinnet- maximum length of segment (terminator to terminator) is 185 meters (607 feet)
Thicknet -maximum length of segment (single run) is 500 meters (1,640 feet)
Unshielded Twisted Pair (UTP) - maximum length of cable between hub and computer is 100 meters (328 feet)
Fiber-Optic - maximum length of cable is 2 kilometers. (6,562 feet)
3. What is a backbone?
A backbone is a generic term used to describe media that interconnects a number of computers, segments or subnets.
In its most common form, a backbone is used to connect hubs. Each