netwoks and the internet Flashcards
chapter 1
what is the internet
computer network that interconnects billions of devices through out the world
5 billion devices were connected to the internet in 2015 , how may is estimated in 2020?
25 billion
how are end systems connected?
network of communication links and packet switches
whats the client/server relationship
asynchronous relationship
what is the internet protocol suite
networking model and a set of communications protocols used for the internet and similar networks
what does the internet protocol suite do?
provides end to end connectivity
specifies how data should be formatted ,addressed ,transmitted ,routed and received at the destination
how many layers are in the internet protocol suite?
4
what are the layers of the OSI 7 layer model
- physical
- data link
- network
- transport
- session
- presentation
- application
what is the OSI 7 layer model
OSI (open systems interconnections) is a model for how applications communicate over a network
computer network architecture into 7 layers
1.physical layer of the osi 7 layer model function
physical -a(not reliable ) direct point to point data connection. a flow of data down through the layers in the source computer, across the network, and then up through the layers in the receiving connection.
2.data link layer of the osi 7 layer model function
a reliable direct point to point data connection
3.network layer of the osi 7 layer model function
addressing routing and (not reliable) delivery of data-grams between points on a network
4.transport layer of the osi 7 layer model function
reliable delivery of packets between points on a network
5.session layer of the osi 7 layer model function
inter host communication and managing sessions between applications
- presentation layer of the osi 7 layer model
data representation ,encryption and decryption and convert machine dependent data to machine independent data