Found 1625 Articles for Computer Network

Fourier analysis is a method of representing general functions by approximate sum of simple trigonometric functions. The method is named after mathematician Jean Baptiste Joseph Fourier who formulated and proved the Fourier series. Fourier analysis is used in electronics, communications and acoustics.The Fourier series decomposes a periodic function as a sum of sine and cosine components as expressed below:where, g(t) is the periodic functionT is the time periodf is the fundamental frequency expressed as 1/Tan is the sine amplitude of the nth harmonicbn is the cosine amplitude of the nth harmonicc is a constantThe values of an, bn and c ... Read More

Ethernet is a set of technologies and protocols that are used primarily in LANs. The performance of Ethernet is analysed by computing the efficiency of the channel under different load conditions.Let us assume an Ethernet network has k stations and each station transmits with a probability p during a contention slot. Let A be the probability that some station acquires the channel. A is calculated as −A = kp (1−p)kpThe value of A is maximized at p = 1/k. If there can be innumerable stations connected to the Ethernet network, i.e. k → ∞, the maximum value of A will ... Read More

The logical link control (LLC) is the upper sublayer of the data link layer of the open system interconnections (OSI) reference model for data transmission. It acts act an interface between the network layer and the medium access control (MAC) sublayer of the data link layer.The LLC sublayer is mainly used for its multiplexing property. It allows several network protocols to operate simultaneously within a multipoint network over the same network medium.LLC Layer in the OSI ModelThe Open System Interconnections (OSI) model is a 7 – layered networking framework that conceptualizes how communications should be done between heterogeneous systems. The ... Read More

Organizationally unique identifier (OUI) refers to a 24-bit number assigned to a manufacturer or a vendor of a network device or station. They are globally unique identifiers assigned by the Institute of Electrical and Electronics Engineers (IEEE) Registration Authority.OUI are typically used for uniquely identifying a particular device connected to the computer network through derived identifiers like the Medium Access Control (MAC) addresses. MAC addresses are of 6 octets ( 48-bits ). Among these, the first three octets of the addresses constitutes the OUI.A 3-octet OUI is generally represented in hexadecimal notation separated by dashes (for example, 1F – 9E ... Read More

Broadcasting in computer network is a group communication, where a sender sends data to receivers simultaneously. This is an all − to − all communication model where each sending device transmits data to all other devices in the network domain.The ways of operation of broadcasting may be −A high level operation in a program, like broadcasting in Message Passing Interface.A low level networking operation, like broadcasting on Ethernet.Broadcasting is shown in the following figure −Advantages of BroadcastingBroadcast helps to attain economies of scale when a common data stream needs to be delivered to all, by minimizing the communication and processing ... Read More

Multicasting in computer network is a group communication, where a sender(s) send data to multiple receivers simultaneously. It supports one – to – many and many – to – many data transmission across LANs or WANs. Through the process of multicasting, the communication and processing overhead of sending the same data packet or data frame in minimized.Ethernet MulticastEthernet multicast constitutes multicasting at the data link layer of the OSI model for Ethernet networks. Ethernet frames for multicasting are identified by a 1 bit in the LSB (least significant bit) of the first byte of the destination address.IP MulticastIP multicast provides ... Read More

Classic Ethernet is the original form of Ethernet used primarily in LANs. It provides data rates between 3 to 10 Mbps.It operates both in the physical layer and in the MAC sublayer of the OSI model. In the physical layer, the features of the cables and networks are considered. In MAC sublayer, the frame formats for the Ethernet data frame are laid down.Classic Ethernet was first standardized in 1980s as IEEE 802.3 standard.Frame Format of Classic EthernetClassic Ethernet frames can be either of Ethernet (DIX) or of IEEE 802.3 standard. The frames of the two standards are very similar except ... Read More

Repeaters are network devices operating at physical layer of the OSI model that amplify or regenerate an incoming signal before retransmitting it. They are incorporated in networks to expand its coverage area. They are also known as signal boosters.Why are Repeaters needed?When an electrical signal is transmitted via a channel, it gets attenuated depending upon the nature of the channel or the technology. This poses a limitation upon the length of the LAN or coverage area of cellular networks. This problem is alleviated by installing repeaters at certain intervals.Repeaters amplifies the attenuated signal and then retransmits it. Digital repeaters can ... Read More

Thick EthernetThick Ethernet was the first commercially available form of cabling supported by Ethernet. It is technically known as 10-BASE-5. Here, 10 is the maximum throughput, i.e. 10 Mbps, BASE denoted use of baseband transmission, and 5 refers to the maximum segment length of 500 metres (1, 600 ft). This type of cabling allows 100 stations to be connected to it by vampire taps.Thin EthernetThin Ethernet, popularly known as cheapernet or thinnet, is among the family of Ethernet standards that uses thinner coaxial cable as a transmission media. It is technically known as 10-BASE-2.Here, 10 is the maximum throughput, i.e. ... Read More

Thin Ethernet, popularly known as cheapernet or thinnet, is among the family of Ethernet standards that uses thinner coaxial cable as a transmission media. It is technically known as 10-BASE-2. Here, 10 is the maximum throughput, i.e. 10 Mbps, BASE denoted use of baseband transmission, and 2 refers to the maximum segment length of about 200 metres (precisely 185 metres).This type of cabling allows a maximum of 30 stations to be connected to it by BNC connectors with 50 centimetres minimum gap between subsequent stations.Features of Cable and NetworkThe salient features of 10-BASE-2 Ethernet cabling are −10-BASE-2 use RG-58 A/U ... Read More