Topic 6, Lesson 2: WANs
Computer
Communications and
Networking
Networking - LANs
Learning
Objectives:
i) Understand what is meant
by computer networking
ii) Explain the advantages of
a Local Area Network (LAN)
iii) Describe the hardware
needed to create a LAN
iv) Understand the different
roles of computers in peer-topeer and client-server
networks
v) Describe (using diagrams)
bus, ring & star network
topologies
Learning Check
What is a Local Area
Network (LAN)?
What is it for?
Networking - LANs
Learning
Objectives:
i) Understand what is meant
by computer networking
ii) Explain the advantages of
a Local Area Network (LAN)
iii) Describe the hardware
needed to create a LAN
iv) Understand the different
roles of computers in peer-topeer and client-server
networks
v) Describe (using diagrams)
bus, ring & star network
topologies
Quick review:
What is a LAN?
• A LAN is a Local Area Network.
• It is a connected set of computers
and other devices.
• Each device is called a node (e.g.
computer, printer, etc.)
• A LAN is installed on one site.
– Relatively small
– All network infrastructure is owned by the
organisation
Networking - LANs
Learning
Objectives:
i) Understand what is meant
by computer networking
ii) Explain the advantages of
a Local Area Network (LAN)
iii) Describe the hardware
needed to create a LAN
Learning Check
What hardware is needed
to make a LAN?
iv) Understand the different
roles of computers in peer-topeer and client-server
networks
v) Describe (using diagrams)
bus, ring & star network
topologies
Networking
Equipment
Networking - LANs
Learning
Objectives:
i) Understand what is meant
by computer networking
ii) Explain the advantages of
a Local Area Network (LAN)
iii) Describe the hardware
needed to create a LAN
iv) Understand the different
roles of computers in peer-topeer and client-server
networks
v) Describe (using diagrams)
bus, ring & star network
topologies
Client-Server and
Peer-to-Peer networks…
What’s the difference?
Networking - LANs
Learning
Objectives:
i) Understand what is meant
by computer networking
ii) Explain the advantages of
a Local Area Network (LAN)
iii) Describe the hardware
needed to create a LAN
iv) Understand the different
roles of computers in peer-topeer and client-server
networks
v) Describe (using diagrams)
bus, ring & star network
topologies
Can you identify the following
Network Topologies?
Today we will discuss WANs
and related topics …
Networking - WANs
Learning
Objectives:
i) Describe the differences
between a LAN and a WAN
ii) Explain the terms IP
addressing, MAC addressing,
packet and protocols
iii) Explain the need for
security measures in
networks, such as:
- User access levels
- Suitable passwords
- Encryption techniques
In pairs, discuss:
What is a Wide Area
Network (WAN)?
•
•
•
iv) Describe and justify
network policies such as:
- Acceptable use
- Disaster recovery
- Failover
- Back up
- Archiving
•
•
•
•
•
How does it
differ from a
LAN?
LANs and WANs
• LAN
–
–
–
Local Area Network
Located on one site
Owner of network owns the infrastructure
• WAN
–
–
–
Wide Area Network
Covers a large geographical area – may be worldwide
Infrastructure may be provided by telecoms companies
• VPN
–
–
–
Virtual Private Network
Uses internet for infrastructure
Need for enhanced security
Networking - WANs
Learning
Objectives:
i) Describe the differences
between a LAN and a WAN
ii) Explain the terms IP
addressing, MAC addressing,
packet and protocols
iii) Explain the need for
security measures in
networks, such as:
- User access levels
- Suitable passwords
- Encryption techniques
•
•
•
iv) Describe and justify
network policies such as:
- Acceptable use
- Disaster recovery
- Failover
- Back up
- Archiving
•
•
•
•
•
The internet is the biggest
WAN there is!
With so many devices and users
connecting up, from different
countries, with different languages and
different laws, there is a need for some
standards …
Main Internet Protocols (rules):
- Addressing Protocols
- Data transfer Protocols
Other Internet Protocols
IP addressing
• Each node on a network has an Internet
Protocol (IP) address.
• It uniquely identifies the node.
• In IPv4 this consists of four octets (8-bit bytes).
• Written as four numbers separated by dots,
e.g. 212.1.45.67
• A device’s IP address
will not necessarily
remain the same each
time it joins a network or
goes on-line
MAC addressing
• MAC: Media Access Control.
• This is a unique
number hardwired
into a device / node.
• It cannot be changed.
• It is a 12-digit
hexadecimal
number, e.g.
53:a0:6f:10:44:bd
Data Packets
• Data is split into packets to be sent
across a network or the internet.
– Packets get sent by different routes
according to availability.
– Packets are reassembled at receiving end.
• Typical packet structure:
source
address
destination
address
sequence
number
Data
Packet Header
Trailer
error
checking
Packet Addresses
• The packet address is like the address on a letter
• The data is sent from one router to another until it
arrives at its destination.
A
B
Protocols
– Protocols are the rules for
communication between devices (&
are set internationally)
– Standard protocols encourage network
development.
– Internet Protocol (IP) is a group of
protocols that underlies the internet
(aka TCP/IP) and we have just seen two
important rules (addressing and data
transfer).
– But there are many other specific
protocols for particular tasks.
Common Transmission Control Protocol (TCP)
and the Internet Protocol (IP)Protocols
Protocol
Meaning
Application
DNS
Domain Name
System
Translates domain names such as
bbc.co.uk into IP addresses.
TLS / SSL
Transport Layer
Security /
Secure Sockets
Layer
Protocols designed for secure
communications (using encryption).
FTP
File Transfer
Protocol
Used for copying files from one
computer to another.
HTTP
Hypertext
For distributing hypermedia files –
Transfer Protocol essentially web pages &their content.
IMAP
Internet
Message
Access Protocol
One method for accessing emails.
POP3
Post Office
Protocol
(version 3)
Another method for accessing emails,
used by most webmail services.
Networking - WANs
Learning
Objectives:
i) Describe the differences
between a LAN and a WAN
ii) Explain the terms IP
addressing, MAC addressing,
packet and protocols
iii) Explain the need for
security measures in
networks, such as:
- User access levels
- Suitable passwords
- Encryption techniques
•
•
•
iv) Describe and justify
network policies such as:
- Acceptable use
- Disaster recovery
- Failover
- Back up
- Archiving
•
•
•
•
•
https://www.youtube.com/watch?v=Ve7_4ot-Dzs
Watch from 1min in…
Networking - WANs
Learning
Objectives:
i) Describe the differences
between a LAN and a WAN
ii) Explain the terms IP
addressing, MAC addressing,
packet and protocols
iii) Explain the need for
security measures in
networks, such as:
- User access levels
- Suitable passwords
- Encryption techniques
Security Measures
Why are such measures
needed?
•
•
•
iv) Describe and justify
network policies such as:
- Acceptable use
- Disaster recovery
- Failover
- Back up
- Archiving
•
•
•
•
•
What are the consequences
of not having them?
Security
• Transmitted data is vulnerable.
• Users on a network do not need to see all data.
• Access levels
– Users granted privileges.
– Associated with login names.
• Passwords
– Must be changed regularly.
– Passwords should be strong.
• Encryption
– Processes turn readable data into “nonsense” and
back again (aids security during data transfer)
– Especially important on wireless networks.
Networking - WANs
Learning
Objectives:
i) Describe the differences
between a LAN and a WAN
ii) Explain the terms IP
addressing, MAC addressing,
packet and protocols
iii) Explain the need for
security measures in
networks, such as:
- User access levels
- Suitable passwords
- Encryption techniques
•
Network Policies – these are
set locally
What network policies do
you think Sidmouth College
has?
•
•
iv) Describe and justify
network policies such as:
- Acceptable use
- Disaster recovery
- Failover
- Back up
- Archiving
•
•
•
•
•
Why are these
needed?
Policies
• Network owners should have policies to
protect their assets.
• Users have responsibilities.
• Acceptable use policies are common.
• Policy ensures that users understand
what is expected of them.
• Sanctions used if users misuse resources.
Disaster Recovery
• Need to plan for worst case scenario.
• Example strategies:
• use of disk protection technology such as RAID;
• surge protectors — to minimise the effect of power
surges on delicate electronic equipment;
• uninterruptible power supply (UPS);
• back-up generator in case of a power failure;
• anti-virus software and other security measures;
• failover systems – these prevent the network from
crashing if a device, cable or node stops working
correctly
• data is regularly copied and archived (saved in an
offline storage place) in case of loss
Networking - WANs
Learning
Objectives:
i) Describe the differences
between a LAN and a WAN
ii) Explain the terms IP
addressing, MAC addressing,
packet and protocols
iii) Explain the need for
security measures in
networks, such as:
- User access levels
- Suitable passwords
- Encryption techniques
•
•
•
iv) Describe and justify
network policies such as:
- Acceptable use
- Disaster recovery
- Failover
- Back up
- Archiving
•
•
•
•
•
Task …
Create a ‘Quick Revision Guide’
about the topics covered
today:
-
What a WAN is;
What an IP address is
and What a MAC
address is;
What a Data Packet is;
The reason why all data
can be sent / received
regardless of country /
language (ie Protocols).
Prezi?
PowerPoint?
Leaflet?