M12: Network Programming Design: Efficiency Techniques and Internet Architecture Flashcards
Denial of service attacks:
bad attackers try to overwhelm a web server by
making requests at the same time, using up all the resources on the web server;
it can often be difficult to distinguish the fake traffic from legitimate network traffic
Event-driven programming:
rather than using blocking system calls,
event-driven programming allows higher performance and resource utilization by
allowing functionality to continue or sleeping until the desired event occurs
○ Event loop:
○ Event handlers:
OSI model:
a formal, standard representation of networking that splits the
network functionality into seven layers.
Internet model:
an informal representation of networking that splits the
network functionality into five layers. This model groups the “application,
presentation, and session” layers of the OSI model together.
Layers of Internet Model
Physical Layer Data Link Layer Network Layer Transport Layer Application Layer
Physical layer:
includes the actual wires and wireless links that
move bits between two physical systems
Data link layer:
determines how the raw bytes should be
transferred over the physical links. In particular, the link layer puts raw bytes into messages, performs error detection and correction in transferred data, includes functions for reliable delivery, and determines where and when to send the data over the links.
Network layer:
includes IP and message routing within the network
Transport layer:
includes the TCP and UDP protocols; creates
network communication channels between different processes on
the same or on different machines through the use of sockets
Application layer:
includes all the user level processes that
require network communication. OSI model splits this into three layers: session, presentation, and application.
Interface :
accepted form of representing and accessing data such that the user
can decode the information
Protocol :
rules and formats that govern communication between two entities
over the network or network boxes
○ Data frame - datalink layer
grouping of raw data bits; the recipient can identify the
frames by the particular sequences of bits that represent the start and end
○ MAC address - datalink layer
unique address that identifies your network card; 48-bit address space
Packet - NW Layer
a method of wrapping data with its control information (e.g. its error detection codes, destination, etc.)
