OSI Flashcards
Layer 6 is also known as?
Presentation Layer
Layer 7 is also known as?
Application Layer
Layer 5 is also known as?
Session Layer
Layer 3 is also known as?
Network Layer
Layer 4 is also known as?
Transport Layer
Layer 1 is also known as?
Physical Layer
Layer 2 is also known as?
Data Link Layer
What is Data Link
The Data Link Layer defines the rules and procedures for hosts as they access the physical layer. The Rules and procedures specify or define:
- how hosts on the network are identified (Physical or MAC address)
- How and when devices can transmit on the network medium (media access control and logical topology)
- how to verify that the data received from the Physical layer is error free (parity and CRC)
- How devices control the rate of data transmission between hosts (flow Control)
What is Transport Layer
The Transport layer provides a transition between the upper and the lower layers of the OSI model, making the upper and lower layers transparent from each other. Transport layer functions include:
- End to end Flow control
- Port and socket numbers
- Segmentation, sequencing and combination
- Connection services, either reliable (connection-oriented) or unreliable (connectionless) delivery of data
What is Physical layer
The physical layer of the OSI model sets standards for sending and receiving electrical signals between devices. Protocols at the physical layer identify:
- How digital data (bits) are converted to electrical pulses, radio waves, or pulses of lights
- Specifications for cables and connectors
- The physical topology.
What is Presentation Layer
The Presentation layer format or “presents” data into a compatible form for receipt by the Application layer or the destination system. Specifically, the Presentation layer ensures:
- Formatting and translation of data between systems.
- Negotiation of data transfer syntax between systems through converting character sets to the correct format.
- Encapsulation of data into message envelopes by encryption and compression.
- Restoration of data by decryption and decompression.
What is Session Layer
The Sessions Layer’s primary function is managing the sessions in which data is transferred. Functions at this layer include:
- Management of multiple sessions (each client connection is called a session). A server can concurrently maintain thousands of sessions
- Assignment of the session ID number to each session to keep data streams separate
- Set Up, maintain, and tear down communication sessions.
What is Application Layer
The Application layer integrates network functionality into the host Operating System, and enables network services. The Application layer does not include specific applications that provide services, but rather provides the capability for services to operate on the network.
Data at the physical layer is known as?
BITS
Services typically associated with the Application layer
- HTTP
- Telnet
- FTP
- TFTP
- SNMP
