|  | 3.1 | Basic LAN Devices
| 3.1.4 | Media
The symbols for media vary. For example: the Ethernet symbol is typically a straight line with perpendicular lines projecting from it; the token-ring network symbol is a circle with hosts attached to it; and for FDDI, the symbol is two concentric circles with attached devices. The basic functions of media are to carry a flow of information, in the form of bits and bytes, through a LAN. Other than wireless LANs (that use the atmosphere, or space, as the medium) and the new PANs (personal area networks, that use the human body as a networking medium!), networking media confine network signals to a wire, cable, or fiber. Networking media are considered Layer 1 components of LANs. You can build computer networks with many different media types. Each media has advantages and disadvantages, what is an advantage for one media (category 5 cost) might be a disadvantage for another (fiber optic cost). Some of the advantages and disadvantages are: Cable length Cost Ease of installation Total number of computers on the media as shown in the popup chart Coaxial cable, optical fiber, and even free space can carry network signals, however, the principal medium you will study is called Category 5 unshielded twisted-pair cable (CAT 5 UTP). To find out more about commercially available media, visit:
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| Blackbox Network Services
| Micro Warehouse