Osi Reference Model

Front 1

What are the 7 layers of the OSI model

Back 1

Application
Presentation
Session
Transport
Network
Data Link (LLC/MAC)
Physical

Front 2

Describe the 1st layer of the OSI model

Back 2

Physical layer: Connects nodes physically and electrically. Covers voltages, transmission timing, initial "handshaking" rules, mode (half/full duplex), connectors, NICs and repeaters. Provides Data Link layer with bits.

Front 3

Describe the 2nd layer of the OSI model

Back 3

Data Link: Transmits data reliably between adjacent nodes along the route. Provides the grammar (protocols), deals with frames not bits, and checks for errors. Provides data link paths to the Network layer.

Front 4

Describe the 3rd layer of the OSI model

Back 4

Network: Uses data link paths to route data through the entire network (packet switching). Converts data from the Transport layer into data packets and sends them to the Data Link layer. Functions like a huge mail room, messages from host placed in packets, addressed, and sent to bottom two layers for transmission.

Front 5

Describe the 4th layer of the OSI model

Back 5

Transport: Provides end to end control by detecting/fixing errors, selecting routes, retransmits lost messages and prevents fast terminals from overwhelming slow terminals.

Front 6

Describe the 5th layer of the OSI model

Back 6

Session: Establishes and terminates session. Controls passwords, enable a user to use half/full duplex, determine who speaks, how, and how often, terminate/reestablish sessions, creates checkpoints, monitors system usage andcan bill users for their time.

Front 7

Describe the 6th layer of the OSI model

Back 7

Presentation: Performs data conversion between different formats, requires each system have same protocols, provides data compaction, code conversions, and data encryption.

Front 8

Describe the 7th layer of the OSI model

Back 8

Application: Provides electronic mail, distributed database services, and really anything the programmer of the application decides to use the data transmissions for.

Front 9

What X standard corresponds to the bottom three layers of the OSI model

Back 9

X.25

Front 10

What are the sub layers of the Data Link layer

Back 10

LLC (IEEE 802.2) and MAC (IEEE 802.3)

Front 11

Describe LLC (Logical-Link-Control)

Back 11

LLC (IEEE 802.3) provides an interface between the MAC sublayer and the Network layer.

Front 12

Describe MAC (Media-Access-Control)

Back 12

MAC sub-layer is concerned with detecting data collisions.