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1.4 Wired and Wireless Networks - Coggle Diagram
1.4 Wired and Wireless Networks
Advantages of Networks
- Users can share files, users can share peripherals (printers and connections to other networks e.g. internet), they can access their files from any computer on the network. Servers can control security, software updates and backup of data. Communication with other people (email and social networking)
Disadvantages of Networks
- Increased security risk to data. Malware and viruses spread very easily between computers. If a server fails, the computer connected to it may not work. The computer may not run more slowly if there is a lot of data travelling on the network.
Types of networks
Local Area Network
- Covers a small geographical area located on a single site. All the hardware for a LAN is owned by the organisation using it. LANs are wired with UTP cable, fibre optic cable or using Wi-Fi
Wide Area Network
- Covers a large geographical area, connecting LANs together. Infrastructure between the LANs is leased from telecommunication companies who own and manage it. WANs are connected with telephone lines, fibre optic cables or satellite links.
Factors that affect the performance of Networks
The number of users
- Too many users or devices on the same network can cause the network to slow down if there is insufficient bandwidth for the data.
Transmission Media
- Wired connections have a higher bandwidth than wireless connections. Fibre optic cables have a higher bandwidth than copper cables.
The error rate
- Less reliable connections increase the number of errors that occur when data is transferred. This means that data has to be resent until it arrives correctly. The signal quality of wireless connections is dependant on the range of the device from the wireless access point and other environmental factors. The signal quality on copper cables is determined by the grade of material used which reduces the interference. The length of the cable is also a factor.
Latency
- The delay from transmitting data to receiving it. Latency is caused by bottlenecks in the infrastructure of the network. For example, by not using switches to appropriately segment traffic on a network. Hardware such as switches and transmission media may not operate at the same speed.
Bandwidth
- The amount of data that can be sent and received successfully. This is not a measure of how fast data travels but how much data can be sent on a transmission media. Measured in bits per second, called the bit rate.
Client Server Network
- A server controls access and security to one shared file store. A server manages access to the internet, printing jobs, provides email services, runs backups of data, makes requests to the server for data and connections.
Advantages
- Easier to manage security of files, easier to take backups of all shared data, easier to install software updates to all computers
Disadvantages
- Can be expensive to set up and maintain, requires IT specialists to maintain, the server is a single point of failure, users will lose access if the server fails
LAN Hardware
Switch
- Sends data between computers on a LAN. Uses the NIC address on a device to route traffic.
Router
- Is needed to connect a LAN to a WAN. Uses the IP address on a device to route traffic to other routers.
Connections between desktop computers and a switch are usually made with
Unshielded Twisted Pair
(UTP) copper cables.
Wireless Access Points
- allowed wireless-enabled devices to access the network. Wireless connections are popular because it avoids the need to install cables.
Bandwidth
on a wireless connection is lower than a wired connection.
Security
is more of a problem on a wireless networks.
Network Interface Card
- connects a wired or wireless network connection. An NIC uses a protocol to ensure successful communications.
Longer distance cables and WANs are usually connected with
fibre optic cable
. It has a higher bandwidth than copper and suffers from less interference.
Copper cables
are cheap and flexible which makes it easier to install
Concept of Virtual Networks
- A VLAN applies to a logical structure to networks independently of the physical structure.
Scalability
- Users can be connected to different switches but appear as if they are on the same segment of the network. Bandwidth is used more efficiently.
Security
- Users cannot access computers in other VLANs even if they are connected with the same switch.
Cost
- You don't need to change the network infrastructure as the business changes.
The Internet
- A global connection of interconnected networks. Web addresses which are easier for humans to remember are converted to IP address for routers by a DNS.
Servers that store data and programs remotely can be accessed and used over the internet are called
cloud storage.
They provide anytime, anywhere, automatic backup and collaboration on documents.
Websites that are stored on servers dedicated to converting web addresses to IP addresses. This is known as hosting. Hosted solutions provide 24/7 access, multiple users and greater security.
Peer to Peer Networks
Peer to Peer Networks
A peer is a computer on the network and is equal to the other peers. Peers serve their own file to each other. Each peer is responsible for its own security and its own backup. Peers usually have their own printers. You can send print jobs to another peer to peer process but that peer must be switched on to be able to communicate with the connected printer.
Disadvantages
- The network is less secure, users will need to manage their own backups and it can be hard to maintain a well ordered file store.
Advantages
- Very easy to maintain, specialist staff are not required. Not dependant on a single computer. Cheaper to set up as no expensive hardware required.