Wired snd wireless newtorks,protocols and layers

What is Ethernet(wired network)

• Ethernet is a wired networking standard to carry electrical signals between devices

• Ethernet is common in most offices and homes to connect devices such a desktop computers & servers

• Ethernet uses twisted pair cables to allow duplex communication

What are properties of wired network

• Speed-Fast data transfer

• Portability-Can't move easily, location is limited by physical cable

• Security-Better physical security

•  Cost-Need more cables to add a new device

• Range-High (up to 100m), less susceptible to interferenceSafety Cables can be trip hazards, need routing along walls, under floors

What is wireless networks and two examples

• A wireless network is a network where connections are made using radio waves to transmit data through the air

• The most common types of wireless connections are:

• Wi-Fi

• Bluetooth

What are advantages and disadvantages of WiFi(wireless network)

• Portability Easy to move around, location is only limited by range

• Cost Less expensive/Easier to setup and add new devices

• Compatibility Most devices are manufactured with a built in Wi-Fi adapter

• Convenient to use

• Can handle lots of users

• Disadvantages of WIFI

• Speed Slower data transfer than Ethernet(wired network)

• Security Less secure than Ethernet

• Range Relies on signal strength to the WAP, signals can be obstructed (up to 90m

What is Bluetooth and its advantages and disadvantages

• Bluetooth is another common standard for wireless networks

• Bluetooth is common in most homes and offices to connect devices such as headphones, controllers, keyboards & mice

• Bluetooth is used typically for a direct connection between two devices 

• Advantages of Bluetooth

• Compatibility Ideal for personal devices and ad-hoc connections

• Power Very low power consumption

• Disadvantages of Bluetooth

• Speed Very slow transfer speeds

• Security Data can be intercepted by anyone in range

• Range - Very short range (10m)

What is encryption and why is it important for wireless networks

• Encryption is a method of scrambling data before being transmitted across a network in order to protect the contents from unauthorised access

• While encryption is important on both wired and wireless networks, it's even more critical on wireless networks due to the data being transmitted over radio waves, making it easy to intercept

How is wireless data encrypted

• Wireless networks are identified by a 'Service Set Identifier' (SSID) which along with a password is used to create a 'master key'

• When devices connect to the same wireless network using the SSID and password they are given a copy of the master key

• The master key is used to encrypt data into 'cipher text', before being transmitted

• The receiver uses the same master key to decrypt the cipher text back to 'plain text' 

• To guarantee the security of data, the master key is never transmitted. Without it, any intercepted data is rendered useless

How is wired data encrypted

• Wired networks are encrypted in a very similar way to a wireless network, using a master key to encrypt data and the same key to decrypt data

• Encryption on a wired network differs slightly as it is often left to individual applications to decide how encryption is used, for example HTTPS

What is an IP address

• An IP (Internet Protocol) address is a unique identifier given to devices which communicate over the Internet (WAN) and route packets

• IP addresses are dynamic, they can change

• IP addresses make it possible to deliver data to the right device

• A device connecting to a network will be given an IP address, if it moves to a different network then the IP address will change

What are the two versions of IP addresses

IPv4 and IPv6

What is IPv4

-Each address is is 8 bytes(32 bits)

-Written as 4 numbers seperate by periods(.), each number in range 0-255

-Example 62.34.89.232

What is a IPv6 address

-each address is 16 bytes(128 bits)

-Written as eight groups separated by colons(:) each group is made up of four hex values representing 26 bits

-Example: 2001:0db1:42ac:21bd:2344:abc1:234b:nbv5

What is a MAC address and example

MAC addressing is used to route frames on a LAN

-It’s represented as 12 hex numbers(48 bits) grouped in pairs with colons

-Example:00:0a:95:9d:68:16

What does any device that has a Network interface card(NIC) have

A MAC address assigned during manufacturing

What is a standard

A set of guidelines that when used with different hardware and software allows them to work with each other (compatibility) and allow data exchange (interoperability)

-Give manufactures and software developers snooty to create hardware and software that function together

Where are standards not used

• Countries that use different plug sockets

• Devices that use different charger cables

What are the examples of computing standards

HTML-standards for creating websites

ASCI/UNICODE-Character set standards

IEE-standards for computer cables

-Document,images and sound standards

What are protocols

Set of rules for how devices communicate and how data is transmitted across a network

What are the 7 protocols

• TCP/IP

• HTTP

• HTTPS

• FTP

• POP

• IMAP

• SMTP

What is TCP/IP

• TCP/IP is two protocols, transmission control protocol (TCP) and internet protocol (IP) that combined allow communication over the internet (WAN)

• TCP is responsible for making sure communication between two routers is error free

• IP is responsible for making sure data is delivered to the right device on a wide area network (WAN)

What is HTTP and HTTPS

• Hypertext Transfer Protocol (HTTP) allows communication between clients and servers for website viewing

• HTTP allows clients to receive data from the sever (fetching a webpage) and send data to the server (submitting a form, uploading a file)

• HTTPS works in the same way as HTTP but with an added layer of security. All data sent and received using HTTPS is encrypted

• HTTPS is used to protect sensitive information such as passwords, financial information and personal data

What is FTP

• File Transfer Protocol (FTP) allows sending and receiving files between computers

• Uploading and downloading files to/from a web server is often completed using FTP

• FTP offers greater efficiency and support for bulk transfers and large files such as resuming interrupted transfers

What is SMTP

Simple Mail Transfer Protocol (SMTP) is a protocol that allows communication between an email sender and the email server

SMTP is used to transfer the senders email to their email providers server and SMTP is used to transfer the email to the recipients email server

What is POP

Retrieve emails from a server.Removes it from the server and transfers to your device when you want to download it

What is IMAP

Retrieves email from a sever. The sever holds the email until you delete it-you can only download a copy

What’s the concept of a layer

Dividing a more complex task of networking into smaller,simpler tasks that work with each other

What does each layer provide a service to

The layer above

What are the advantages of layering

• ayers are self-contained which makes managing, repairing and upgrading easier as each layer can be worked on independent of other layers

• Layers allow for focus on specific parts of a protocol without affecting other layers

• Promotes data exchange (interoperability) between hardware and software

What layer does a TCP/IP use

A 4 layer model called stack