2.1 Flashcards
define client-server architecture
server:
always on host
permanent IP address
data centres for scaling
clients: communicate with server not always connected may have dynamicIP addresses do not communicate directly with each other
define P2P architecture
not always on server
arbitrary end systems directly communicate
peers request service from other peers, provide service in return to other peers
peers are intermittently connected and change IP addresses
define self scalability
new peers bring new service capacity and service demands
define process and what are 2 kinds of processes
process is a program running with in a host
within the same host two processes communicate using interprocess communication
processes in different hosts use message
What does the client process do?
Initiates communication
What does the server process do?
waits to be contacted
What do sockets do?
send and received messages to/from their sockets, like a door
What does the application layer protocol define?
- types of messages exchanged
- message syntax
- rules
- open protocols
- proprietary protocols
- message semantics
What transport service does an app need?
data integrity
- some apps require 100% reliable data transfer(web transaction, file transfer)
- other apps (audio) can tolerate some loss
timing
- some apps require low delay to work as intended
throughput
-some apps(multimedia) require minimum amount of throughput to work as intended
security
-encryption/data entrigrity
Features of TCP
reliable transport
flow control
congestion control
doesn’t provide timing, minimum throughput guarantee , security
connection-oriented: requires setup between client and server processes
Features of UDP
unreliable data transfer between sending and receiving process
doesn’t provide reliability,flow control, congestion control, timing, throughput guarantee, security, or connection setup
