Week 6

Question 1

What is the difference between the internet and the WWW?

Answer 1

Internet existed first.
Internet: Global network of networks. Can be seen as an infrastructure.
WWW: Easy way to navigate the internet. It is a collection of information that is accessed through the internet.

Question 2

What is the evolution of the internet?

Answer 2

• 1969 ARPANET (defence). Connected were 4 uni’s
• 1980 NSFNET -> non defense network -> Dutch CWI first internetional node
• 1989 Concept of WWW
• 1990: CIX - Commercial use of the internet
• 1991: Prototype of WWW developed at CERN

Question 3

What is the WWW

Answer 3

It is a network of documents stored at different computers. A client’s browser sends a request for a page to a server. When the server receives the request it can send the document to the clients browser.

They use HTTP protocol

Question 4

What is the HTTP protocol?

Answer 4

Hyper Text Transfer Protocol

-> Used to send and retrieve documents

Question 5

What is web 2.0

Answer 5

Everyone can be author on the internet. Comes through the development of Internet, WWW and Wlan

Question 6

What types of connecton (switching) are possible?

Answer 6

Circuit Switching (think telephones)
Packet Switching

Question 7

What is circuit switching?

Answer 7

• An operator sets up a connection through a specific line to send data from A to B
• Info is sent which costs bandwidth
• Other users can still use that dedicated line, but not unlimitedly
• Connection has to stay in place the whole duration of the data transfer

Question 8

What are advantages and disadvantages of circuit switching?

Answer 8

+ minimal delay

• wastes bandwidth
• requires dedicated path

Question 9

What is packet switching?

Answer 9

• Data file is split up in packets
• Each packet is sent individually
• Not directly sent to B, but forwarded from node to node in the direction of B
• Does follow an organized path

Question 10

What are advantages and disadvantages of circuit switching?

Answer 10

+ minimal delay
+ not wasting bandwidth
+ No dedicated circuit

• Packets can get lost

Question 11

What protocols are used when connecting to other nodes?

Answer 11

• IP Protocol

- TCP Protocol

Question 12

What is the IP protocol?

Answer 12

• Makes packets
• Makes adresses
• Gives addresses to computers and destinations
• Gives feedback to reroute package if lost

Question 13

What is the TCP Protocol?

Answer 13

• Transport protocol
• Guarantees delivery in the correct order
• Receives the packets and checks them

Question 14

What are possibilities within a LAN?

Answer 14

Ethernet

Token Ring

Question 15

What is the Ethernet?

Answer 15

A connection of local devices to one bus

Question 16

What is the CSMA/CD Protocol?

Answer 16

The protocol used in ethernet.

• Any devices in the bus can start sending
• If one devices sends through the bus, other devices can not send because there will be collision
• Sending device needs to listen to avoid collision

Question 17

What is a token ring?

Answer 17

There is one coordinator device. Gives token to devices in the bus that want to send data. You can only send with a token -> avoids collision.
-> Difficult if system needs to expand

Question 18

What is a system of systems?

Answer 18

• Complex system in which each element is a system itself.
• There is no central control;
• Each system works autonomousy;
• Each system needs to collaborate;
• Each system should work if others do not work;

Question 19

What are architectual principles of system of systems?

Answer 19

• They have stable intermediate forms;
• Only control what is really needed;
• The interfaces are specified. Here is where the designer has some control;
• Elements need incentive to collaborate
• Collaboration most important

Question 20

What are current developments in networking?

Answer 20

• E-commerce
• Semantic web
• Social media
• Mobile internet
• Cloud
• IoT