Worksheets[3.1] Protocols, Reference Models, Data Encapsulation and Access
Total questions: 78
Worksheet time: 49mins
Which of the following are benefits of using a layered model in networking? (Multiple Answers)
It assists in protocol design by defining clear interactions between layers (simplification)
It encourages vendor competition by allowing interoperability
It ensures changes in one layer affect all others for faster adaptation
It provides a common language to describe networking functions
It prevents technology or capability changes in one layer from affecting other layers
above and below
Which layer of the OSI model is responsible for data formatting?
3 - Network layer
7 - Application layer
6 - Presentation layer
4 - Transport layer
Which layer of the OSI model is responsible for error detection?
3 - Network layer
2- Data Link layer
4 - Transport layer
7 - Application layer
What is the primary function of the Application layer in the OSI model?
To manage data flow
To provide process-to-process communication
To format data for transmission
To route packets
What is the function of the Session layer in the OSI model?
To provide end-to-end communication
To route packets
To format data for transmission
To manage data exchange
Which of the following is a characteristic of the OSI model?
It has four layers
It does not support routing
It is a proprietary model
It is used for standardizing network communication
What is the purpose of the Network layer in the OSI model?
To provide a common representation of data
To encrypt data
To manage data flow
To route packets
Which layer breaks data into segments and ensures reliable delivery?
Layer 7
Layer 6
Layer 4
Layer 3
At which OSI layer are MAC addresses used?
3 - Network
2 - Data Link
4 - Transport
5 - Session
At which layer of the OSI model would a logical address be added during encapsulation?
1 - Physical
2 - Data Link
4 - Transport
3 - Network
At which OSI layer is a destination port number added to a Protocol Data Unit (PDU) during the encapsulation process?
1 - Physical
2 - Data Link
4 - Transport
3 - Network
At which OSI layer is data added to a PDU during the encapsulation process?
(a) Layer
Which of the ff. are the two layered models describe network operations?
Open System Interconnection (OSI)
Reference Model
TCP/IP Reference Model
Ethernet Model
Application/Data Link Model
Name the OSI layer that encrypts and compresses data.
(a) Layer
What is the main function of the Data Link layer?
To route data packets
To facilitate the exchange of data frames over a common media
To manage data flow between applications
To provide end-to-end communication
This layer transfers raw bits (0s and 1s) over a physical medium like cables or wireless.
(a) Layer
The OSI model has 7 layers. Which of the following is the correct order of the layers (assume encapsulation from Layer 7 to Layer 1)?
Application → Presentation → Session → Transport → Network → Data Link → Physical
Physical → Data Link → Network → Transport → Session → Presentation → Application
Presentation → Application → Session → Data Link → Network → Transport → Physical
Which layer of the TCP/IP model is responsible for determining the best path through the network?
Application layer
Internet layer
Transport layer
Network Access layer
What is the role of the Application layer in the TCP/IP model?
To support communicate between devices
To determine the best path through the network
To control hardware devices associated with the network
To represent and encode data to the user
What is the role of the Network Access layer in the TCP/IP model?
To support communicate between devices
To determine the best path through the network
To control hardware devices associated with the network
To represent and encode data to the user
What is the role of the Transport layer in the TCP/IP model?
To support communicate between devices
To determine the best path through the network
To control hardware devices associated with the network
To represent and encode data to the user
Which of the following is a characteristic of the TCP/IP model?
It is widely used for internet communication
It is a proprietary model
It has seven layers
It does not support routing
Which of the following is a characteristic of the TCP/IP model?The TCP/IP model has 4 layers. Which of the following shows the correct order of the layers (assume encapsulation from top to bottom)?
Application → Internet → Transport → Network Access
Application → Transport → Internet → Network Access
Network Access → Internet → Transport → Application
Which layers of the OSI model map/correspond to the Application layer of the TCP/IP model?
Application
Presentation
Session
Data Link
Physical
Which layers of the OSI model map/correspond to the Network Access layer of the TCP/IP model?
Application
Presentation
Session
Data Link
Physical
What does the term 'segmentation' refer to in data encapsulation?
Formatting data for transmission
Encrypting data for security
Breaking up messages into smaller units
Combining multiple messages into one
What does the term 'multiplexing' refer to in data communication?
Combining multiple data streams into one
Breaking data into smaller segments
Formatting data for transmission
Encrypting data for security
What is the primary purpose of network protocols?
To establish a physical connection
To define a common set of rules for communication
To manage hardware devices
To encrypt data
What are the two primary benefits of segmentation? (2 answers)
It increases the size of each data frame to reduce network load
It increases speed by allowing large data to be broken into smaller parts, enabling multiple conversations on the network
It increases efficiency by making error detection and recovery easier — only the missing segment needs to be resent
It enables faster internet speeds by upgrading hardware automatically
It forces all devices to send data at the same time
Why do we need sequencing in networking?
It ensures that the data segments can be reassembled in the correct order regardless if some arrive out-of-order.
It ensures that data segments are automatically encrypted for security.
It assigns IP addresses to every segment in the network, ensuring that they can determine their destination.
As data moves down the protocol stack (from Application to Physical layer), each layer adds its own header/trailer to the data — this is called (a) .
What does the term 'protocol data unit' (PDU) refer to?
The size of the data packet
The data at each layer of the OSI model as it passes through the network stack
The data format used in encryption
The final data sent over the network
A PDU has a different name to reflect its new functions.
What is the PDU name at the application layer?
(a)
A PDU has a different name to reflect its new functions.
What is the PDU name at the transport layer ASSUMING TCP was used?
(a)
A PDU has a different name to reflect its new functions.
What is the PDU name at the transport layer ASSUMING UDP was used?
(a)
A PDU has a different name to reflect its new functions.
What is the PDU name at the network layer?
(a)
A PDU has a different name to reflect its new functions.
What is the PDU name at the data link layer?
(a)
A PDU has a different name to reflect its new functions.
What is the PDU name at the physical layer?
(a)
What does 'data encapsulation' allow in network communication?
It allows data to be compressed
It allows data to be encrypted
It allows data to be stored
It allows data to be transported across the network
TRUE or FALSE:
Encapsulation is a top-down process.
TRUE
FALSE
Which layers use addressing to deliver data from source to destination? (Multiple Answers)
Network Layer
Data Link Layer
Transport Layer
Physical Laye
Which of the following best describes the difference between the addressing used by the Network and Data Link layers?
The Network layer uses IP addresses, while the Data Link layer uses MAC addresses to deliver PDUs between devices on the same LAN.
The Data Link layer uses IP addresses, and the Network layer uses MAC addresses to deliver data across the internet.
The Network layer only delivers data within the same LAN, while the Data Link layer handles delivery across different networks.
Which of the following statements are true?
I. Source IP address in a packet represents the address of the sending device (original source)
II. Destination IP address in a packet represents the receiving device (final destination of the packet)
I only
II only
Both I and II
None
Which of the following statements are true?
I. IP addresses indicate the source and destination IP address regardless of whether the devices are on the same LAN or not.
II. IP addresses change as the packet travels across the network in order to find the needed destination.
I only
II only
Both I and II
None
An IP adddress has two parts.
This is the left-most part of the address that indicates the network in which the IP address is a member. All devices on the same network will have the same network portion of the address.
Network portion (IPv4) or Prefix (IPv6)
Host portion (IPv4) or Interface ID (IPv6)
An IP adddress has two parts.
This is the right-most (REMAINING) part of the address that identifies a specific device on the network. This portion is unique for each device or interface on the network.
Network portion (IPv4) or Prefix (IPv6)
Host portion (IPv4) or Interface ID (IPv6)
When two devices are on the same IP network, the data doesn't need to pass through a router.
TRUE
FALSE
TRUE OR FALSE:
If the Source MAC address is the originator on the link, then the Destination MAC address will always be on the same link as the source, even if the ultimate destination is remote.
TRUE
FALSE
Case-by-Case Basis
In an Ethernet frame, what is the correct order of MAC addresses?
Source MAC address followed by Destination MAC address
Destination MAC address followed by Source MAC address
Both MAC addresses appear randomly in the frame
Only the Source MAC address is included in the frame
PC1 has the IP address 192.168.1.10, and it wants to communicate with a web server that has the IP address 172.16.1.5. Both devices are connected to their own local networks.
What will PC1 do to send a message to the web server?
It will send the frame directly to the web server using the web server’s MAC address.
It will check if the server is on the same network using subnet masks, and if not, send the packet to the default gateway.
It will change its own IP address to match the web server’s network portion.
It cannot send the message because the IP addresses are different.
On an Ethernet network, the data link addresses are known as Ethernet Media Access Control (MAC) addresses. These are physically embedded into the (a) .
MAC addresses are expressed as 12 _________ digits.
hexadecimal
octal
decimal
A user on PC1 cannot access a web server on a remote network. The PC can ping other devices on the same LAN but not the web server. What is the most likely cause?
The PC’s IP address is incorrect
The PC’s MAC address is duplicated
The default gateway is not set on the PC
The PC’s firewall is turned off
When PC1 sends data to a remote web server, which of the following correctly describes what happens at the router (default gateway)?
The router changes the destination IP address to its own and forwards the packet
The router only looks at the MAC address and forwards the frame directly to the web server
The router removes the Layer 2 frame, checks the IP address, and forwards the packet based on Layer 3
The router converts the data back to application format and resends it as a new message
What happens to the MAC addresses when a packet moves from PC1 to a remote web server through multiple routers?
The MAC addresses stay the same from source to destination
The MAC addresses change at each hop along the path
The MAC addresses are ignored after the first hop
The MAC addresses are used only by the web server
PC1 wants to send a message to a web server on a remote network. As the packet travels through multiple routers to reach the server, which of the following statements is TRUE?
Both the source and destination MAC addresses stay the same from PC1 to the Web Server.
The source IP address changes at every router, while the MAC address stays the same.
The source and destination IP addresses stay the same, but the MAC addresses change at each hop.
The IP and MAC addresses both change at every hop.
What does the term 'de-encapsulation' refer to?
The process of segmenting data
The process of adding headers to data
The process of encrypting data
The process of removing headers from data as it moves up the stack
Which of the following is NOT a requirement for protocols?
Message encoding
Message formatting
Message delivery options
Message encryption
A sensor generates and sends the temperature data.
A server receives and processes the data.
The Ethernet cable is the medium used to carry the data.
Which of the following correctly identifies the roles of the components in this network communication?
Sensor – Source
Ethernet – Destination
Server – Channel
Sensor – Destination
Server – Channel
Ethernet – Source
Sensor – Channel
Server – Source
Ethernet – Destination
Sensor – Source
Server – Destination
Ethernet – Channel
Which of the ff. are the requirements to successfully deliver a message that is understood by the receiver?
An identified sender and receiver
Common language and grammar
Speed and timing of delivery
Confirmation or acknowledgment requirements
Common delivery method
Which statement is correct about network protocols?
Network protocols define the type of hardware that is used and how it is mounted in racks.
They define how messages are exchanged between the source and the destination.
They all function in the network access layer of TCP/IP.
They are only required for exchange of messages between devices on remote networks.
If decoding reverses the process of encoding, what does encoding do?
It displays the message in a human-readable format
It translates the message into a format suitable for transmission
It checks the message for errors before sending
It compresses the message to save storage space
What process involves placing one PDU inside of another PDU?
encapsulation
encoding
segmentation
flow control
A large file is being sent over the network. The data is segmented into smaller pieces, encoded into buts, and sent as multiple signals. What network protocol requirement is this?
Message Encoding
Message Format and Encapsulation
Message Size
Message Timing
Message Delivery Options
Message Timing has three methods.
This method allows a computer to react accordingly when it requests data from a server and the server takes too long to respond.
Flow Control
Response Timeout
Access Method
Message Timing has three methods.
What method can be used by two computers to ensure that packets are not dropped because too much data is being sent too quickly?
Flow Control
Response Timeout
Access Method
Message Timing has three methods.
What method determines when someone can send a message especially considering collisions?
Flow Control
Response Timeout
Access Method
What does the term 'unicast' refer to in network communication?
One to one communication
One to many communication
Broadcast communication
Multicast communication
Which of the following best describes the difference between multicast and broadcast communication?
Multicast ensures guaranteed delivery; Broadcast does not.
Multicast is used only in wired networks; Broadcast is used only in wireless networks.
Multicast delivers data to a group of interested receivers; Broadcast delivers data to all devices on the local network.
Multicast delivers data to all devices on the local network; Broadcast delivers data to a group of interested receivers.
Which step of the communication process is concerned with properly identifying the address of the sender and receiver?
Formatting
Encapsulation
This routing protocol enable two or more devices to communicate over one or more networks. Some examples include IP, TCP, HTTP.
Network Communciations
Network Security
Routing
Service Discovery
What is the purpose of a protocol suite?
To provide a single protocol for communication
To group inter-related protocols for communication functions
To establish hardware standards
To define encryption methods
What does the term 'broadcast' mean in networking?
Sending data to a selected group of devices
Sending data to one specific device
Sending data to multiple devices at once
Sending data to all devices on a network
Which organization is responsible for the development of the OSI model?
Institute of Electrical and Electronics Engineers
International Organization for Standardization
Internet Society
Internet Engineering Task Force
What is the significance of message timing in network protocols?
It specifies the encryption method
It defines the format of the message
It manages the rate of data transmission
It determines the size of the message
What is the purpose of the MAC address in networking?
To route data across the internet
To encrypt data packets
To provide a unique identifier for devices on the same network
To identify the network segment
What is the primary purpose of flow control in network communication?
To manage the size of messages
To format data for transmission
To ensure data is transmitted at an efficient rate
To encrypt data packets
What is the significance of the default gateway in a network?
It is the primary source of network power
It is the main server for data storage
It is the router that connects to other networks
It is the device that encrypts data
