context

Question 1

what is internet

Answer 1

the largest engineered system ever created by mankind.
it can be seen as a:
1. A physical infrastructure of hardware components
2. A network architecture
3. A communication service used by apps

Question 2

what is a ISPs

Answer 2

ISPs grants the access, use, management, and participation in the Internet through an agreement/contract.
Each ISP is itself a network of packet switches and communication links.

Question 3

tipes of ISPs

Answer 3

• residential ISPs (telephone companies);
• corporate ISPs;
• university ISPs;
• ISPs that provide WiFi access in airports, hotels, coffee shops, and other public places;
• mobile (cellular) ISPs.

Question 4

what is a protocol

Answer 4

A protocol defines the format and the order of messages exchanged between two or more communicating entities, as well as the actions taken on the transmission and/or receipt of a message or other event
(standardised sequence of actions and reactions to let everything work)

Question 5

network physical components

Answer 5

• End system: host / terminal
• Connection links: Communication channels (optical fiber, coaxial cables,
  radio, satellite, …)
• Nodes: routers, switch

Question 6

what is a end system

Answer 6

• Any end system is able to send and receive information for its final application/service.
• Very different characteristics,
  functionalities and scope

Question 7

what are links? make examples

Answer 7

• Different types of physical connections
• Different technologies
• Different rates

examples:
- Fiber optics
- Radio antenna
- Twisted pair
- Coaxial cable

Question 8

what are nodes? make examples

Answer 8

They manage the packet, forwarding them from source to destination (They operate at different «levels» of the network)

examples:
- router
- switch
- access point

Question 9

what is a network access? make examples

Answer 9

they are technologies for Internet access.

examples:
- Dialup via modem
- ADSL
- Fiber optics
- Mobile network

Question 10

which are the different types of network and how are they connected

Answer 10

• LAN: Local Area Network (Buildings or campus)
• MAN: Metropolitan Area Network (few tens of km)
• WAN: Wide Area Network (large coverage)

Internet exchanges (IXs or IXPs) are physical
locations where networks come together to
connect and exchange traffic with each other

Question 11

what are Internet exchanges (IXs or IXPs)

Answer 11

Internet exchanges (IXs or IXPs) are physical
locations where networks come together to
connect and exchange traffic with each other