3. • handles the transfer of bits from
one computer to another
• bits are actually converted into the
electrical signals that travel across
the physical circuit
• conveys the bit stream - electrical
impulse, light or radio signal --
through the network at the electrical
and mechanical level
4. • data packets are encoded and
decoded into bits
• getting data from one particular
medium to another
• formats the message into data
frames and adds a customized
header containing the hardware
destination and source address
5. • data packets are encoded and
decoded into bits
• MAC sub layer controls how a
computer on the network gains
access to the data and permission
to transmit it
• LLC layer controls frame
synchronization, flow control and
error checking
6. • responsible for transporting traffic
between devices that are not
locally attached
• provides switching and routing
technologies, creating logical paths,
known as virtual circuits, for
transmitting data from node to
node
7. • provides transparent transfer of
data between end users
• providing reliable data transfer
services to the upper layers
• controls the reliability of a given
link through flow control,
segmentation/desegmentation, and
error control
• can keep track of the segments and
retransmit those that fail.
8. • controls the dialogues
(connections) between computers
• establishes, manages and terminates
the connections between the local
and remote application
• provides for full-duplex, half-duplex,
or simplex operation, and establishes
checkpointing, adjournment,
termination, and restart procedures
9. • responsible for graceful close of
sessions, session checkpointing
and recovery
10. • establishes a context between
Application Layer entities
• provides independence from
differences in data representation
• transform data into the form that
the application layer can accept
• formats and encrypts data to be
sent across a network, providing
freedom from compatibility
problems
11. • interacts with software
applications that implement a
communicating component
• functions typically include
identifying communication
partners, determining resource
availability, and synchronizing
communication.
Connectors, pins, electrical currents, encoding and light modulation are all part of different physical layer specifications
Media Access Control (MAC) layer and the Logical Link Control (LLC) layer
Media Access Control (MAC) layer and the Logical Link Control (LLC) layer
The transport protocols used on the Internet are TCP and UDP.
Some examples of session-layer implementations include Zone Information Protocol (ZIP), the AppleTalk protocol that coordinates the name binding process; and Session Control Protocol (SCP), the DECnet Phase IV session layer protocol.
responsible for graceful close of sessions, which is a property of the Transmission Control Protocol Some examples of session-layer implementations include Zone Information Protocol (ZIP), the AppleTalk protocol that coordinates the name binding process; and Session Control Protocol (SCP), the DECnet Phase IV session layer protocol.
Some examples of presentation layer coding and conversion schemes include common data representation formats, conversion of character representation formats, common data compression schemes, and common data encryption schemes.
When identifying communication partners, the application layer determines the identity and availability of communication partners for an application with data to transmit. When determining resource availability, the application layer must decide whether sufficient network resources for the requested communication exist. In synchronizing communication, all communication between applications requires cooperation that is managed by the application layer.
In this example, Sam will send an E-mail to Charlie. This illustration will show how Sam’s message will be delivered to Charlie.
