Chapter 2: The OSI Reference Model

Encapsulation

the process of encoding data as it goes down the OSI model layers

Binding

communication processes that are related to each other are bound at a particular layer

Application Layer

where users actually interact with the computer; this acts as an interface between application programs

Presentation Layer

presents data to the application layer and is responsible for data translation and code formatting

Session Layer

responsible for setting up, managing and tearing down session between presentation layer entities; also provides dialogue control between devices

Transport Layer

segments and reassembles data into a data stream; this layer can be connectionless or connection-oriented

Virtual Circuit

when the senders TCP process contacts the destination TCP process to establish a connection - this type of communication is connection-oriented

Flow Control

provides a means for the receiver to govern the amount of data sent by sender

Buffer

temporary memory section where overflow of datagrams are stored(only works if datagram is part of a small burst)

Window

quantity of data segments (in bytes) that transmitting machine is allowed to send without receiving an acknowledgment

Network Layer

manages logical device addressing, tracks the location of devices on the network and determines the best way to move data

Data Link Layer

provides the physical transmission of the data and handles error notification network topology and flow control

802.1

LAN/MAN management (and MAC bridges)

802.3

CSMA/CD (Ethernet)

802.11

Wireless LAN

802.15

Wireless PAN

MAC

defines how packets are placed on the media (data link sublayer)

LLC

responsible for identifying network layer protocols, encapsulating them

Physical Layer

sends and receives bits

PDU

hold the control info attached to the data at each layer of the model (usually attached to header but can also be found in trailer).

Modulation

process of varying one or more waveform properties (carrier signal) with signal that contains info to be transmitted