Lesson 1 Flashcards
What is a network?
Is a set of serial lines used to attach dumb terminals to mainframes computers
A comp network consist of ?
Hosts and the communication system
What is a link and a node?
A link is a physical medium that connects computers or nodes
A node is piece of hardware such as pc , router
Type of connectivity in direct links
Point_to _ point. Physical links are sometimes limited to a pair of nodes
Multiple access. More than two nodes may share a single physical link
The most important icon of comp networking is ?
Cloud
Types of switched network
Circuit switched networks.e.g telephone
Packet switched networks.e.g computer network
What is the difference between circuit and packet switched network?
Source nodes sends a stream of bits across the circuit to the destination node
Discrete blocks of data are sent in a store and forward manner
A node that connects two or more networks is called?
A router or a gateway
Types of multiplexing
Time division M
Frequency division M
Code division multiple access
Why statistical multiplexing is efficient ?
Because data us transmitted fork each user on demand rather than in a predetermined slot. If only one flow had data to send it gets to transmit that data without waiting for its quantum to come around
Types of failures
Bit errors. 0 is turned into 1
Packet loses. due to lack of buffers spaces
Node / link level failure
What is encapsulation?
Is the process of wrapping data with the necessary control information as it travels across different layers of the network protocol stack
List OSI layers
Physical
Data link
Network
Transport
Sessions
Presentation
Applications
Network performance Is measured in two fundamental ways
Bandwidth (no of bits that can be transmitted over s network in a period of time)
Latency (time it takes for a msg to travel from one end of the network to another)
