Network Hardware

Network Hardware: Now it’s period to change our consideration from the Apps, social trends and social facets of networking (the fun substance) to the official and technical matters involved in network design (the work substance). There is no usually acknowledged classification into which all network computers established, but two categories of computer networks stand out as important: the first one is transmission technology and the second is scale.

Generally, there are two categories of transmission technology that is commonly used. Which are as follows;

1. Broadcast links.
2. Point-to-point links.

Broadcast links network In-Network Hardware has a single transmission medium that is shared by all the equipment or the devices on the network. In the context of the network, short messages called data packets which are sent by any device or machine are acknowledged by all the other devices or machines. The given address inside the data packets or with the messages is for the recipient. On receiving a data packet, the recipient first checks the address of the data packet. If the address of the data packet is the same recipient’s address, then the recipient will receive this data packet; If the address of the data packet is of another recipient, it will ignore it. The broadcasting system also allows the possibility of data packet addressed to all recipients by using a special code within the address of the data packet. When a data packet is sent with a packet address, every recipient on the network receives this packet with their address. This mechanism is called broadcasting.  In contrast, the point-to-point links network contains a lot of connections among distinct pairs of devices and machines. When the data packet is sent from the source to the destination, the packet has to pass through one or more devices in this network. Most of the different lengths can often be found, so it is important to find a good one in this network. Generally, small and geographically local networks use the broadcasting network, while the large-scale network is usually a point-to-point network. In a point-to-point network, a single sender and a single receiver can communicate with each other which is also called unicasting. An alternate standard for classifying networks is their scale. In the below figure we classify multiple processor systems by their physical size.

# classification of interconnected processors by scale.

• Personal Area Network

Generally, in the Network Hardware personal area network called PANs. In the personal area, the network has communication between person to person with specific devices or areas. A common example of a personal area network is a wireless network that is connected to a personal computer for communication. Almost every personal computer is attached to the mouse, keyboard, monitor, printer and other basic input/output devices. If the wireless connection is not possible, then the personal computers can be connected with the Ethernet cable.

Personal area network can be interconnecting with many of other technologies which are communicated to each other in a short distance, such as Bluetooth, library books and RFID on smartcards.

• Local area network

Generally, in the Network Hardware local area network called LANs. Local area network is a private network which is connecting inside and nearby in a single building such as office, home, and an organization. Local area network is broadly used to connect the personal computer for sharing the resource, communication and to interchange the information. when a local area network using in an organization then these network is called enterprise network and this network can be established with the wireless connections and wired network.

IEEE 802.11 is the standard for the wireless local area local network which is known as Wi-Fi that has become very widespread. It sends the data with 11 to 100 Mbps speed.

Wired LANs utilize a scope of various transmission technology. The vast majority of them use copper wires, but some use of optical fiber. LANs are limited in size, which implies that the worst-case scenario transmission time is limited and known ahead of time. Knowing these limits assists with the task of structuring network system protocols. Commonly, wired LANs keep running at speeds of 100 Mbps to 1 Gbps, have a low delay (microseconds or nanoseconds), and make not very many errors.

The topology of numerous wired LANs is constructed from point-to-point paths. IEEE 802.3, famously called Ethernet, is, by far, the most widely recognized kind of wired LAN.

Both wireless and wired communicated network systems can be partitioned into static and dynamic designs, dependent upon how the channel is allocated. A typical static part is partition time into discrete intervals and utilizes a round-robin procedure, enabling each machine to communicate just when its schedule slot comes up. The dynamic allocation may have consisted of two procedures, the first one is centralized and the second is decentralized. There is a single entity that can have processed in the centralized medium allowance procedure. For example, it determines the packet who goes to next in the cellular network. In the decentralized medium allowance process, there is no single or central entity. In this procedure, every device or machine can decide for itself to transmit the packet or not.

• Metropolitan Area Network

In the Network Hardware MAN (metropolitan network) covers the city. The best-known examples of MAN are the cable television networks, available in many cities. These systems are derived from older public antenna systems used in areas where the reception of television programs was poor. In these early systems, a large antenna was placed at the top of a nearby hill, and a signal was sent to subscribers.

At first, it was a special system developed locally. Then companies started taking risks in business and got local government contracts to connect entire cities. The next step was TV programming and even full channels exclusively for cable TV. Often, these channels were highly specialized, like all news, sports, cooking, gardening, and so on. But from the beginning to the end of the 1990s, they were only intended for television reception.

However, cable TV is not the only MAN, though. Recent developments in wireless high-speed Internet access have led to the emergence of another MAN, standardized as IEEE 802.16 and commonly known as WiMAX.

• Wide Area Network

In the Network Hardware, A global network (WAN) covers a large geographical area, often a country or a continent. We begin our discussion with a wired extended network, taking the example of a company with branches in different cities.

In the above figure, the WAN is a network connecting offices in Perth, Melbourne, and Brisbane. In each of these offices, computers are designed to execute user programs (i.e., applications). We will follow the traditional usage and call these host machines. The rest of the network that connects these nodes is called the communication subnet or, more simply, the subnet. The job of the subnet is to transfer messages from one host to another, just as a telephone system transmits words (actually only sounds) from the speaker to the listener.

In most global networks, a subnet consists of two distinct components: the transmission lines and switching elements. Transmission lines move bits between machines. They can be made of copper wire, optical fiber or even radio communication. Most companies do not have power lines, so they rent lines to a telecommunications company. Switching elements, or simply switches, are specialized computers that connect two or more transmission lines. When data arrives on an incoming line, the switching element must select the outgoing line to which they are to be sent.

In most global networks, the network contains many transmission lines, each connecting a pair of routers. If two routers that do not share a transmission line want to exchange data, they must do so indirectly through other routers. There may be multiple route on the network that connects these two routers. The way the network decides which route to use is called a routing algorithm. Many of these algorithms exist. The way each router decides where to send a packet is called a transmission algorithm. Many of them exist too.

Other types of WAN use a lot of wireless technology. In satellite systems, every computer on Earth has an antenna through which it can send and receive data from an orbital satellite. All computers can listen to the satellite’s output and, in some cases, they can also listen to the transmission upstream of their other computers to the satellite. Satellite networks are intrinsically transmitted and are particularly useful when transmission properties are important.

• Internetworks

In the Network Hardware, A set of interconnected (a combination of PAN, LAN, MAN, WAN) networks is called an internetwork or the Internet. The Internet uses Internet service providers to connect corporate networks, home networks, and many other networks. There are many networks around the world, often with different hardware and software. People connected to the network often want to communicate with people connected to another. To meet this desire, it is necessary that different networks, often incompatible, are connected.

Subnetworks, networks, and interconnections are often confused. The term “subnet” makes more sense in the context of the global network, where it refers to all the routers and lines of communication belonging to the network operator. By analogy, the telephone system consists of telephone switching points interconnected by high-speed lines, as well as between houses and offices – low-speed lines. These lines and equipment belonging to and operated by the telephone company constitute the sub-network of the telephone system. The phones themselves (hosts by this analogy) are not part of the subnet.

A network is a combination of a subnet and its hosts. However, the word “network” is also often used in a general sense. A subnet can be described as a network, as in the case of the “ISP network”. The internal network can also be described as a network, as in the case of a wide area network.

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