Computer Network Components

Computer Network is composed of several basic elements that include hardware and software components, namely:
1. Hardware Components
Personal Computer (PC), Network Interface Card (NIC), cable and network topology.
2. Component Software
Network Operating Systems, Network Adapter Drivers, Network Protocols.

A. Network devices

1. Repeater
Function to receive signals then pass back the received signal with the same power. With the repeter, the signal from one computer to another computer that is located far apart.

2. Hub
Its function is similar to a repeater hub consists of only a few ports, so that the hub is also called multiport repeter. Repeaters and hubs work at the physical layer so it does not have knowledge about the destination address. Although the hub has several ports, but still make use of the broadcast method of sending signals, so that if one port is busy then the other ports have to wait if you want to send a signal.

3. Bridge
Functioning like a repeater or hub, but more clever because it works on data link layer that has the ability to use the MAC address is in the process of sending frames to the destination address.

4. Switch
Functions the same as the bridge just switch consists of several switch ports so-called multiport bridge. With these capabilities if one of the busy port on the switch then the other ports can still function. But bridges and switches can not forward IP packets addressed other computers in different logical network.

B. Type, Type of Cable and Wiring

Each type of cable has the ability and their specifications are different, because it made the introduction of cable types. There are several types of cables that are widely known, namely twisted pair (STP UTPunshielded twisted pair and shielded twisted pair), coaxial cable and fiber optic.

1. Thin Ethernet (thinnet)

Thin Ethernet or thinnet have advantages in terms of the relatively cheaper cost compared to other types of cabling and the installation of components easier. The length of thin wire coaxial/RG-58 between 0.5 - 185 m and a maximum of 30 computers terhubung.Kabel coaxial type is widely used among amateur radio, particularly to transceivers that do not require a large power output.
To be used as network devices, coaxial cable of this type must comply with the IEEE 802.3 10Base2 standard, where the average diameter of about 5mm and usually black or other dark color. Each device (device) is connected with a BNC T-connector. The cable type is also known as thin Ethernet or thinnet. Coaxial cable of this type, such as the type RG-58 A / U or C / U, if implemented with Tconnector and terminator in a network, must follow the rules as follows:
• Each end of the cable are 50-ohm terminator.
• The maximum length of cable is 1,000 feet (185 meters) per segment.
• Each segment is a maximum of 30 devices connected to the network (devices)
• Network cards can simply use an onboard transceiver, do not need additional transceiver, except for the repeater.
• Maximum there are 3 segments connected to each other (populated segments).
• Each segment should be equipped with one ground.
• minimum length between the T-Connector is 1.5 feet (0.5 meters).
• Maximum cable length in one segment is 1.818 feet (555 meters).
• Each segment has a maximum of 30 devices connected.

2. Thick Ethernet (Thicknet)

With a thick Ethernet or thicknet, the number of computers that can be connected in a network will be more and the distance between the computers can be enlarged, but the cost of procurement is more expensive wiring and installation is relatively more difficult compared with thinnet. In Thicknet transceiver used to connect each computer to the network system and connectors used are type DIX connector. Maximum transceiver cable length 50 m, Thick Ethernet cable maximum length 500 m with a maximum 100 transceiver connected. Coaxial cable of this type is specified by IEEE 802.3 10Base5 standard, where the cable has an average diameter of 12mm, and is usually given a yellow color; cable type is commonly referred to as thick Ethernet or standard Ethernet, or simply abbreviated thicknet, or even referred to as yellow cuman cable.Kabel this Coaxial (RG-6) when used in the network have the specifications and rules as follows:
• Each end must be terminated with 50-ohm terminator (recommended using
terminator that has been assembled, instead of using a single 50-ohm resistors 1 watt, because the resistor has a fairly wide voltage dissipation).
• Maximum of three segments with the equipment connected (attached devices) or a populated segments.
• Every network card has an additional transmitter (external transceiver). Each segment is a maximum of 100 network devices, including repeaters in this case.
• Maximum cable length per segment is 1640 feet (or about 500 meters).
• Maximum distance between the segment is 4920 feet (or about 1500 meters).
• Each segment must be grounded.
• Rarely a maximum between the tap or pencabang from the main cable to the device (device) is 16 feet (5 meters). Rarely minimum inter-tap is 8 feet (2.5 meters).