Session 1. Basic networking Concepts
Computer network:
A computer network is a group of more computers connected to each electronically. This means that the computers can "talk" to each other and that every computer in the network can send information to the others. Usually, this means that the speed of the connection is fast - faster than a normal connection to the Internet.
Network Components
There are three primary components to understanding networks: 1. Physical Connections; 2. Network Operating System; and 3. Application Component.
The physical components are the network topology and network connecting devices, which include network interface cards (NIC), cabling, connections, and all other hardware to connect the computers. Data communication:
Data communication refers to the transmission of the digital signals over a communication channel between the transmitter and receiver computers. Communication is possible only with wired and wireless connectivity of the computers with each other. All the computers, in the logically and physically networks have to follow the same rules known as Protocols such as TCP/IP, IPX/SPX and NETBEUI etc. Today, there are many computer networking technologies such as LAN, MAN, WAN, WLAN, ISDN, ATM, Frame Relay, X.25, Bluetooth, GPRS, CDMA and many others.Analog and digital signal
The analog signal and digital signal are differ in their data format which they carry during the transmission. Let’s see the some difference in both. Analog signal are continues and digital signal is discrete, analog signal are continuously variable and digital signal are based on 1’s an d 0’s, The primary disadvantage of an analog signal is noise and Noise in digital signal is much easier to filter out, Sound waves are a continuous wave and as such are analog in the real world and in digital signal is used in computer which is used in every office, Analog signal required lesser bandwidth capacity and digital signal require greater bandwidth capacity.
Session 3: Network communication Mediums
Network Medium:
The typical fiber optic cable used for a fiber link segment is a multi-mode fiber cable (MMF) with a 62.5 micron fiber optic core and 125 micron outer cladding (62.5/125). Each link segment requires two strands of fiber, one to transmit data, and one to receive data. There are many kinds of fiber optic cables available, ranging from simple two-strand jumper cables with a PVC outer jacket material on up to large inter-building cables carrying many fibers in a bundle.
The fiber connectors used on link segments are generally known as "ST" connectors. The formal name of this connector in the ISO/IEC international standards is "BFOC/2.5." The ST connector is a spring-loaded bayonet connector, whose outer ring locks onto the connection, much like the BNC connector used on 10BASE2 segments. The ST connector has a key on an inner sleeve and also an outer bayonet ring. To make a connection you line up the key on the inner sleeve of the ST plug with a corresponding slot on the ST receptacle, then push the connector in and lock it in place by twisting the outer bayonet ring. This provides a tight connection with precise alignment between the two pieces of fiber optic cable being joined. Transmission medium:
Physical path between transmitter and receiver
May be guided (wired) or unguided (wireless)
Communication achieved by using em waves
Characteristics and quality of data transmission
Dependent on characteristics of medium and signal
Guided medium
Medium is more important in setting transmission parameters
Wifi
Wifi, is a mechanism for wirelessly connecting electronic devices. A device enabled with Wi-Fi, such as a personal computer, video game console, smatphone, or digital audio player, can connect to the Internet via a wireless network access point. An assess point (or hotspot) has a range of about 20 meters (65 ft) indoors and a greater range outdoors. Multiple overlapping access points can cover large areas.
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