5.1 Flashcards
What is the Internet?
A network of networks. (global system of computers connected together)
What means that the Internet is redundant?
Can reach a computer through multiple paths
What means that the Internet is hierarchical?
Organized into ever smaller groups
The Internet allows computers to send
information (bytes) to each other.
Explain the birth of the Internet.
It started in 1957 in response to Sputnik.
US initiative lead to ARPA.
ARPANET in 1969 connected 4 universities.
There was an evolution on the internet. Distinguish between early-use, 1990s and today.
Early-use: email, file transfer, scientific calculations.
1990s: user-friendly tools, public subscriptions.
Today: 15,14 billion nodes, 5,19 billion nodes, over 330000000 TB of daily data!
When you use a website, you are…
connected to a large network of computers in the internet.
Explain what’s the server and the client in the client-server network model.
Server: power computer that can provide resources or services to one or more clients.
Client: a computing device that needs access to the resources or services provided by your server.
The client is connected to a network of computers & your server should be connected to this network as well.
Most servers tend to have a…
one-to-many relationship with clients.
Explain what the traceroute command does.
It’s a tool that shows the path data takes from your computer to a destination on the Internet. It displays the IP addresses of the routers it passes through & measures how long it takes to reach each one.
We can diagnose network issues & understand the route data follows.
Explain how the client-server model works.
- client asks server for information (request)
- request is sent to server
- server decodes request, sends back information (response)
- client interprets response
Explain the client-server model with an example.
If you are loading a website, then the client is your computer, the server is another computer at the URL and the request is ask for a webpage.
Internet is a type of network, which one? Develop the answer.
Internet is a WAN in which all computers communicate using a standardized protocol known as IP.
URL:
Uniform Resource Locator
Protocol:
rules for information
Domain Name:
gets converted to an IP adress via a Domain Name Server (DNS)
IP Adress:
computer-readable
Hierarchy:
each byte of the adress gets more specific
A protocol specifies how the communication is handled by establishing a…
standardized vocabulary.
A protocol can specify two things:
Hardware details: frequency at which the data is transmitted.
Software details: representation of an address (name in the network).
Which is the protocol suite used for the Internet?
TCP/IP
The TCP/IP Protocol sets…
the rules for sending information between computers.
Why is the TCP/IP Protocol important? What would happen if it didn’t exist?
The TCP/IP is important because we need a standardized vocabulary for the Internet, also be able to have global communication, reliability, security, good addressing and routing… If these protocols didn’t exist, we will lack of standardized rules for communication, data exchange, or addressing. Therefore, the network will become chaotic and unreliable with low efficiency
Which are the layers in the TCP/IP Protocol?
Application layer
Transport layer
Internet layer
Network layer
Explain briefly the network layer.
Captures the physical aspects of data transmission such as the media used (wire/wireless) & the hardware related protocols.
Explain briefly the internet layer.
Looks after the logical transmission of data. We define the logical address (IP) of our devices connected to the Internet in this layer.
Explain briefly the transport layer.
This layers is responsible for end-to-end communication, specifically error-free transfer. Ex: TCP & UDP protocols.
Explain briefly the application layer.
This is where your server needs to define its networking preferences such as using SSL, etc.
In the application layer, arrival protocols facilitate…
data conversion & interpretation for specific applications.
In the application layer, arrival protocols define…
rules for data presentation (HTML/CSS), encryption, and session management (cookies).
Name two types of protocols related to the application layer. (what are they used for?)
HTTP (Hypertext Transfer Protocol): used for web browsing, defines how web browsers & servers communicate.
SMTP (Simple Mail Transfer Protocol): used for email transmission between mail servers.
The transport layer is responsible for…
end-to-end communication & data integrity.