LAN
Now that we know about the physical structures of a network we need to cover the
types of network we can find today.
LAN – Local Area Network
• Privately owned
• Can be a network in a home, office, building or campus.
4.5.2 WAN
WAN – Wide Area Network
• Can be a network spanning a town, state, or different country.
• WAN is created by the communication companies and leased by an
organization
4.6 Protocols
In a previous lesson we mentioned TCP/IP protocol but now we will talk about it
with the attention it deserves
TCP/IP stands for Transmission Control Protocol / Internet Protocol
These Protocols are organized in layers that each provides a specific function when
sending information through a network such as the Internet.
7
1. Physical Layer – Concerned with physical aspects
2. Data-Link Layer – Doesn’t know the actual destination it just receives the
information and passes it along.
3. Network Layer – Concerned with sender to receiver. It creates a connection
between the source and destination computer. This layer includes the
Internet Protocol, which defines the structure and format of the information.
4. Transport Layer – makes sure the data is sent at a specific rate and sequence.
In other words, flow control. This layer includes the TCP aspect of the
protocol
5. Application Layer – Deals with the user interface that you need to view the
message like outlook for an email. This layer contains protocols such as
• HTTP – Hypertext Transfer Protocol – how we access the World
Wide Web.
• SMTP – The main protocol use in e-mail services
• FTP – File Transfer Protocol transferring files between hosts