OSI Model

Question 1

The main device used to break up collision domains, this is also done by default.

Answer 1

Switch

Question 2

The main device used to break up broadcast domains, by default. They also break up collision domains.

Answer 2

Router

Question 3

Two advantages to using routers in your network:

Answer 3

1) They don’t forward broadcasts by default

2) They can filter the network based on layer 3 information such as an IP address.

Question 4

4 ways a router functions in your network:

Answer 4

Packet switching
Packet filtering
Internet-work communication
Path selection

Question 5

Main purpose of (layer 2) Switches

Answer 5

Forward or filter FRAMES
Optimize a LAN’s performance
Provide more bandwidth for the LAN’s users

Question 6

Layer 7 of OSI:

Answer 6

Application (All)

Question 7

Layer 6 of OSI:

Answer 7

Presentation (People)

Question 8

Layer 5 of OSI:

Answer 8

Session (Seem)

Question 9

Layer 4 of OSI:

Answer 9

Transport (To)

Question 10

Layer 3 of OSI:

Answer 10

Network (Need)

Question 11

Layer 2 of OSI:

Answer 11

Data Link (Data)

Question 12

Layer 1 of OSI:

Answer 12

Physical (Processing)

Question 13

Application layer functions:

Answer 13

File, print, message, database, and application services.
File transfers
Email
Enabling remote access
Network management activites
Client/server processes
Information location

Question 14

Presentation layer functions:

Answer 14

Translation services to ensure successful data transfer

Question 15

Session layer functions:

Answer 15

Dialog control.
Setup, management, and dismantling sessions between Presentation layer entities and keeping user data separate.
Uses three different modes: simplex, half-duplex, and full-duplex.

Question 16

One-way communication.

Answer 16

Simplex

Question 17

Two-way communication in only one direction at a time.

Answer 17

Half-duplex

Question 18

Two-way communication involving transmitting and receiving at the same exact time.

Answer 18

Full-duplex

Question 19

Transport layer functions:

Answer 19

Segments and reassembles data into a single data stream. Takes all the various data received from upper-layer applications, then combine it into the same, concise data stream. (TCP and UDP)

Question 20

TRANSPORT:
For reliable transport to occur, a device that wants to transmit must first establish a connection-oriented communication session with a remote device-its peer system-known as a call setup or a three-way handshake. Once this process is complete, the data transfer occurs, and when it’s finished, a call termination takes place to tear down the virtual circuit.

Answer 20

Connection-Oriented Communication

often referred to as OVERHEAD

Question 21

TRANSPORT:
Its job is to ensure data integrity at the TRANSPORT LAYER by allowing applications to request reliable data transport between systems.

Answer 21

Flow control

Question 22

TRANSPORT:

A service is considered connection-oriented if it has the following characteristics:

Answer 22

A virtual circuit, or “three-way handshake,” is set up.
It uses sequencing. (Segments placed in order)
It uses acknowledgments.
It uses flow control.

Question 23

TRANSPORT:
The quantity of data segments, measured in bytes, that a transmitting machine is allowed to send without receiving an acknowledgement is called?

Answer 23

A window

Question 24

TRANSPORT:
A technique that requires a receiving machine to communicate with the transmitting source by sending an acknowledgement message back to the sender when it receives data.

Answer 24

Positive ACKNOWLEDGEMENT with retransmission

Question 25

TRANSPORT: Transport layer, working in tandem with the Session layer, also separates the data from different applications, an activity known as:

Answer 25

Session multiplexing

Question 26

Network layer functions:

Answer 26

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

Question 27

By default, will not forward any broadcast or multicast packets. Use the logical address in a Network layer header to determine the next-hop router to forward the packet to. Use access lists, created by an admin, to control security based on the types of packets allowed to enter or exit an interface. Provide layer 2 bridging functions if needed and can simultaneously route through the same interface. Provide connections through VLANS Provide QoS for specific types of network traffic

Answer 27

Routers

Question 28

Data link layer functions:

Answer 28

Provides the physical transmission of data and handles error notification, network topology, and flow control.

Question 29

Data link layer formats the messages, each called a ____________, and adds a customized header containing the hardware destination and source address.

Answer 29

Data frame

Question 30

Responsible for the actual unique identification of each device that resides on a local network.

Answer 30

Data link layer

Question 31

The IEEE Ethernet Data Link Layer has two sub-layers:

Answer 31

Media Access Control (MAC) | Logical Link Control (LLC)

Question 32

Defines how packets are placed on the media. Contention for media access is "first come/first served" access where everyone shares the same bandwidth-hence the name. Physical addressing is defined here as well as logical topologies.

Answer 32

Media Access Control (MAC)

Question 33

Responsible for identifying Network layer protocols and then encapsulating them. Header tells the Data Link layer what to do with a packet one a frame is received.

Answer 33

Logical Link Control (LLC)

Question 34

Layer 2 switching is considered hardware-based bridging because it uses specialized hardware called:

Answer 34

Application-specific integrated circuit (ASIC) | High gigabit speeds with very low latency rates.

Question 35

The time measured from when a frame enters a port to when it exits a port.

Answer 35

Latency

Question 36

Physical layer functions:

Answer 36

Send bits and receives bits.

Question 37

Changes in voltage from high to low and low to high.

Answer 37

State transitions

Question 38

Bit length and expression form of a MAC address

Answer 38

48 bits, hexadecimal

Question 39

HTTP, POP3, SMTP: protocols.

Answer 39

Application (Layer 7)

Question 40

TCP, UDP: protocols.

Answer 40

Transport (Layer 4)

Question 41

IP: protocol.

Answer 41

Network (Layer 3)

Question 42

Ethernet, Point-to-Point Protocol (PPP), T1: protocols.

Answer 42

Data Link (Layer 2)

Question 43

Two computers use a protocol to communicate with the same layer on another computer. Header information added by a layer of the sending computer is processed by the same layer of the receiving computer.

Answer 43

Same-layer interaction

Question 44

On a single computer, one layer provides a service to a higher layer. The software or hardware that implements the higher layer requests that the next lower layer perform the needed function.

Answer 44

Adjacent-layer interaction