Hey everyone,
This week we will discuss about networking. The lec notes are cover the introduction, importance of networking, network components, methods, networks devices and software. But we just focus about the introduction, types of networking and network components. Others will discuss next week….I think so……….
1st of all, we talk about computer networking. What is computer networking? Computer networking is connecting a computer with other computers or other devices to enable them to communicate with each other such as
· Computer devices/equipments
· transmission media to send/control data/signals,
· Communication devices to transmit/send data from sources to destinations
· Software
Next, is about types of the networking. Common examples of area network types are:
LAN - Local Area Network
WAN - Wide Area Network
PAN - Personal Area Network
MAN - Metropolitan Area Network
Last, is about network components. Network components can be categories into 5. There are terminals, transmission media, network electronics, software and network architecture standards.
1. Terminals & workstation: Normally refers to data sources and destinations. Example: Personal computers, terminals, workstations, computers, Automatic teller machines (ATM)
2. Transmission media: The physical media used to transmit data in a networked environment. It is also use to transmit signal and electrical pulse through a medium. 2 types of transmission media are bounded/guided and unbounded/unguided. Examples of bounded media are twisted pair wire, coaxial cable and fiber optic cables. Examples of unbounded are AM & FM radio, TV broadcasting, satellite communication, microwave radio, infrared signals
3. Network electronic devices are devices that control data transmission from sources to destinations. It also act as interface between different transmission media or communication protocol. For examples: Bridges, concentrators, routers, Front End Processors, Private Branch, Switches Exchange (PBX), Hubs, Multiplexers, and Gateways.
4. Software: At the nodes, it involves techniques and protocols. Functions of the software are measure the data transmits to the destination.
5. Network architecture standards: Architecture is blueprint of standards for a network consisting of items such as choice of media, media interfaces, encoding methods, transmission protocols, routing protocols and so on. It is needed to ensure interoperability between various devices and equipment made by different vendors.
More information:
1. Bridges
A Bridge does just what you would expect it to do - it joins two networks together so as far as data packets are concerned it looks like one large network
A bridge is not as capable as a Router - but it is less expensive.
2. Hub
The network 'Hub' allows computers to share data packets within a network.
Each computer will be connected to a single 'port' on the hub. So if you purchase an '8 port hub', you will be able to connect up to eight computers together.
You can also 'daisy chain' hubs to allow even more computers to join the network.
However there is a problem with doing this - see 'Switches' for more details.
Typical network making use of a hub:
3. Switches
A switch has a number of ports and it stores the addresses of all devices that are directly or indirectly connected to it on each port.
As a data packet comes into the switch, its destination address is examined and a direct connection is made between the two machines.
4. Protocols
A 'protocol' is a rather technical word. But it simply means an agreed method of doing something.
A 'NETWORK PROTOCOL' is the agreed method of communication to be used within the network.
Each device / computer will use this protocol.
5. End nodes
Within a vast computer network, the individual computers on the periphery of the network, those that do not also connect other networks, and those that often connect transiently to one or more clouds are called end nodes. Typically, within the cloud computing construct, the individual user / customer computer that connects into one well-managed cloud is called an end node. Since these computers are a part of the network yet unmanaged by the cloud's host, they present significant risks to the entire cloud. This is called the End Node Problem. There are several means to remedy this problem but all require instilling trust in the end node computer.
if your computer does not use the AOL protocol (and the chances are it won't). Then how do you get email to your friend on the AOL network?
Answer: A gateway.
A gateway converts the data passing between dissimilar networks so that each side can communicate with each other. i.e converts data into the correct network protocol.
The gateway is a mixture of hardware components and software.
This is unlike a standard 'Bridge' which simply joins two networks together that share the same protocol.
A Router is a device that transfers data from one network to another in an intelligent way. It has the task of forwarding data packets to their destination by the most efficient route.
In order to do this, the router has a micro computer inside it. This holds a table in memory that contains a list of all the networks it is connected to, along with the latest information on how busy each path in the network is, at that moment. This is called the 'routing table'
7. Bluetooth
Bluetooth is a proprietary open wireless technology standard for exchanging data over short distances (using short-wavelength radio transmissions in the ISM band from 2400–2480 MHz) from fixed and mobile devices, creating personal area networks (PANs) with high levels of security. It can connect several devices, overcoming problems of synchronization. The devices can switch roles, by agreement, and the slave can become the master. At any given time, data can be transferred between the master and one other device.
This is a very familiar method of transferring data if you are at all aware of your remote control ! The television remote control makes use of an infra-red link. Personal organisers often make use of an infra-red link to synchronise calendars and 'to-do' lists.
Take a look!!!
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