Module 5: Communication Principles Flashcards
Explain the importance of standards and protocols in network communications.
5.1.1 Communication Protocols
Communication in our daily lives takes many forms and occurs in many environments. We have different expectations depending on whether we are chatting via the internet or participating in a job interview. Each situation has its corresponding expected behaviors and styles.
Before beginning to communicate with each other, we establish rules or agreements to govern the conversation. These agreements include the following:
- What method of communication should we use?
- What language should we use?
- Do we need to confirm that our messages are received?
Noted
Method, Language, and Confirmation Strategies
Before communication can begin, we may have to reach an agreement on the method used.
Before communication can begin, we may have to reach an agreement on the language used.
Communication is successful when the intended message has been received and confirmed.
These rules, or ___, must be followed in order for the message to be successfully delivered and understood.
protocols
Among the protocols that govern successful human communication are these:
- An identified sender and receiver
- Agreed upon method of communicating (face-to-face, telephone, letter, photograph)
- Common language and grammar
- Speed and timing of delivery
- Confirmation or acknowledgment requirements
- The techniques that are used in network communications share these fundamentals with human conversations.
Think about the commonly accepted protocols for sending text messages to your friends.
Noted
Just like humans, computers use ___, or ___, to communicate.
rules, protocols
___ are required for computers to properly communicate across the network.
Protocols
In both a wired and wireless environment, a ___ is defined as an area where all hosts must “speak the same language,” which, in computer terms means they must “share a common protocol.”
local network
If everyone in the same room spoke a different language, they would not be able to communicate. Likewise, if devices in a local network did not use the same protocols, they would not be able to communicate.
___ define many aspects of communication over the local network. These include message format, message size, timing, encoding, encapsulation, and message patterns.
Networking protocols
Protocol Characteristic
When a message is sent, it must use a specific ___ or structure. These depend on the type of message and the channel that is used to deliver the message.
Message format
Protocol Characteristic
The rules that govern the ___ of the pieces communicated across the network are very strict. They can also be different, depending on the channel used.
When a long message is sent from one host to another over a network, it may be necessary to break the message into smaller pieces in order to ensure that the message can be delivered reliably.
Message size
Protocol Characteristic
Many network communication functions are dependent on ___. It determines the speed at which the bits are transmitted across the network. It also affects when an individual host can send data and the total amount of data that can be sent in any one transmission.
Timing
Protocol Characteristic
Messages sent across the network are first converted into bits by the sending host. Each bit is ___ into a pattern of sounds, light waves, or electrical impulses depending on the network media over which the bits are transmitted. The destination host receives and decodes the signals in order to interpret the message.
Encoding (encoded)
Protocol Characteristic
Each message transmitted on a network must include a header that contains addressing information that identifies the source and destination hosts, otherwise it cannot be delivered.
___ is the process of adding this information to the pieces of data that make up the message. In addition to addressing, there may be other information in the header that ensures that the message is delivered to the correct application on the destination host.
Encapsulation
Protocol Characteristic
Some messages require an acknowledgment before the next message can be sent. This type of request/response ___ is a common aspect of many networking protocols. However, there are other types of messages that may be simply streamed across the network, without concern as to whether they reach their destination.
Message pattern
5.1.3 Check Your Understanding - Communication Protocols
Bianka, a Polish traveler in Hanoi, Vietnam, stops and asks Nguyệt for directions to the Ngoc Son Temple. They verbally communicate and determine that they both speak English. After receiving directions in English to the temple, Bianka repeats them to Nguyệt. Nguyệt says, “Yes, that is correct.” Select the order of the communications protocols used in this scenario?
◯ method, language, confirmation
◯ method, confirmation, language
◯ confirmation, method, language
◯ language, method, confirmation
method, language, confirmation
Bianka and Nguyệt first decided on the method of communication (verbal). Then they determined the that both speak English (language). Finally, Bianka repeated the directions (confirmation).
5.1.3 Check Your Understanding - Communication Protocols
Rory is studying the fields inside an Ethernet frame for an upcoming test and notices that the destination Media Access Control (MAC) address is listed first before the source MAC address. Which of the following protocol characteristics is Rory investigating?
◯ encoding
◯ message pattern
◯ message timing
◯ timing
◯ encapsulation
encapsulation
Networking protocols often have some type of addressing information to indicate the source and destination for the message.
5.1.3 Check Your Understanding - Communication Protocols
As Rory continues to study Ethernet, he discovers that a frame can typically be 64 to 1518 bytes of information that is converted into a series of bits before being sent out on the network. Which two protocol characteristics did Rory learn about for Ethernet?
▢ message pattern
▢ encapsulation
▢ encoding
▢ message size
▢ timing
encoding
message size
Networking protocols typically specify the maximum size for a message. In the case of Ethernet, there is also a minimum size of 64 bytes. In addition, Ethernet specifies a method for encoding the bits so that the destination can decode the message.
5.2.2 The Internet and Standards
With the increasing number of new devices and technologies coming online, how is it possible to manage all the changes and still reliably deliver services such as email? The answer is internet standards.
A standard is a set of rules that determines how something must be done. Networking and internet standards ensure that all devices connecting to the network implement the same set of rules or protocols in the same manner. Using standards, it is possible for different types of devices to send information to each other over the internet.
For example, the way in which an email is formatted, forwarded, and received by all devices is done according to a standard. If one person sends an email via a personal computer, another person can use a mobile phone to receive and read the email as long as the mobile phone uses the same standards as the personal computer.
Noted
A ___ is a set of rules that determines how something must be done.
standard
___ and ___ standards ensure that all devices connecting to the network implement the same set of rules or protocols in the same manner.
Networking, internet
Using standards, it is possible for different types of devices to send information to each other over the internet.
For example, the way in which an email is formatted, forwarded, and received by all devices is done according to a standard. If one person sends an email via a personal computer, another person can use a mobile phone to receive and read the email as long as the mobile phone uses the same standards as the personal computer.
5.2.3 Network Standards Organizations
An internet standard is the end result of a comprehensive cycle of discussion, problem solving, and testing. These different standards are developed, published, and maintained by a variety of organizations.
When a new standard is proposed, each stage of the development and approval process is recorded in a numbered Request for Comments (RFC) document so that the evolution of the standard is tracked. RFCs for internet standards are published and managed by the Internet Engineering Task Force (IETF).
Other standards organizations that support the internet include:
* IEEE (Institute of Electrical and Electronics Engineers)
* IANA (Internet Assigned Numbers Authority)
* ICANN (Internet Corporation for Assigned Names and Numbers)
* IETF (Internet Engineering Task Force)
* ITU (International Telecommunication Union)
* TIA (Telecommunications Industry Association)
Noted
When a new standard is proposed, each stage of the development and approval process is recorded in a numbered ___ document so that the evolution of the standard is tracked.
Request for Comments (RFC)
RFCs for internet standards are published and managed by the ___.
Internet Engineering Task Force (IETF)
5.2.4 Check Your Understanding - Communications Standards
The rules that govern network communications including the message format, message size, timing, and encapsulation, are known as network:
◯ messaging
◯ protocols
◯ signaling
◯ encoding
protocols
Protocols are the rules that govern network communications including the message format, message size, timing and encapsulation.
5.2.4 Check Your Understanding - Communications Standards
The IETF (Internet Engineering Task Force) records and publishes internet standards in documents known as:
◯ Internet Specification Standards (ISS)
◯ Internet Protocol Standards (IPS)
◯ Request for Comments (RFC)
◯ IETF Standards Documents (ISD)
Request for Comments (RFC)
The IETF publishes internet standards known as RFCs.
Here are the common protocols that make up computer messages:
- Ethernet (Defines wired network communication at the data link layer)
- IP (Internet Protocol – Handles addressing and routing of packets across networks)
- TCP (Transmission Control Protocol – Ensures reliable, ordered, and error-checked delivery of data)
- HTTP (Hypertext Transfer Protocol – Facilitates communication between web browsers and servers)
Noted
The ___ protocol governs network interface card to network interface card communication in the same network.
Ethernet
___ governs communication from the original source all the way to the final destination. It ensures that the message gets there, and routers along the way determine where the packet is going.
IP (Internet Protocol)
___ makes sure the information gets there reliably. If packets arrive out of order, it ensures they are reassembled in the correct sequence.
TCP (Transmission Control Protocol)
___ governs the exchange or transfer of HTML. When we request or download a webpage, the message contains all of these protocols.
HTTP (Hypertext Transfer Protocol)
5.3.2 Video - The Protocol Stack
Successful communication requires the use of several protocols. When a device sends a message, it actually uses multiple protocols. This is known as a Protocol Stack. Here, I am showing the TCP/IP model, which consists of different layers: the Network Access Layer, Internet Layer, Transport Layer, and Application Layer.
When a device creates a message, it utilizes protocols from different layers. For example, at the Network Access Layer, the Ethernet protocol is used for communication within the same network. Next, at the Internet Layer, the IP protocol (either IPv4 or IPv6) ensures that the message reaches its final destination, whether within the same network or across multiple networks.
At the Transport Layer, the TCP (Transmission Control Protocol) ensures reliable communication. Finally, at the Application Layer, protocols such as HTTP (Hypertext Transfer Protocol) facilitate the transfer of HTML content.
As you can see, sending a message requires multiple protocols working together within the protocol stack.
Noted
5.3.3 The TCP/IP Model
Layered models help us visualize how the various protocols work together to enable network communications. A layered model depicts the operation of the protocols occurring within each layer, as well as the interaction with the layers above and below it. The layered model has many benefits:
- Assists in protocol design, because protocols that operate at a specific layer have defined information that they act upon and a defined interface to the layers above and below.
- Fosters competition because products from different vendors can work together.
- Enables technology changes to occur at one level without affecting the other levels.
- Provides a common language to describe networking functions and capabilities.
The first layered model for internetwork communications was created in the early 1970s and is referred to as the internet model. It defines four categories of functions (Application, Transport, Internet, Network Access) that must occur in order for communications to be successful. The suite of TCP/IP protocols that are used for internet communications follows the structure of this model. Because of this, the internet model is commonly referred to as the TCP/IP model.
Noted
___ help us visualize how the various protocols work together to enable network communications.
Layered models
A ___ depicts the operation of the protocols occurring within each layer, as well as the interaction with the layers above and below it.
layered model
The first layered model for internetwork communications was created in the early 1970s and is referred to as the ___.
internet model
The first layered model for internetwork communications was created in the early 1970s and is referred to as the internet model. It defines four categories of functions (Application, Transport, Internet, Network Access) that must occur in order for communications to be successful.
The suite of TCP/IP protocols that are used for internet communications follows the structure of this model. Because of this, the internet model is commonly referred to as the ___.
TCP/IP model
TCP/IP Model Layer
TCP/IP Model Layer
* Application - Represents data to the user, plus encoding and dialog control.
* Transport - Supports communication between various devices across diverse networks.
* Internet - Determines the best path through the network.
* Network Access - Controls the hardware devices and media that make up the network.
Noted
TCP/IP Model Layer
- Application - Represents data to the user, plus encoding and dialog control.
- Transport - Supports communication between various devices across diverse networks.
- Internet - Determines the best path through the network.
- Network Access - Controls the hardware devices and media that make up the network.
TCP/IP Model Layer
Represents data to the user, plus encoding and dialog control.
Application
TCP/IP Model Layer
Supports communication between various devices across diverse networks.
Transport
TCP/IP Model Layer
Determines the best path through the network.
Internet
TCP/IP Model Layer
Controls the hardware devices and media that make up the network.
Network Access
5.3.4 The OSI Reference Model
There are two basic types of models that we use to describe the functions that must occur in order for network communications to be successful: protocol models and reference models.
- Protocol model - This model closely matches the structure of a particular protocol suite. A protocol suite includes the set of related protocols that typically provide all the functionality required for people to communicate with the data network. The TCP/IP model is a protocol model because it describes the functions that occur at each layer of protocols within the TCP/IP suite.
- Reference model - This type of model describes the functions that must be completed at a particular layer, but does not specify exactly how a function should be accomplished. A reference model is not intended to provide a sufficient level of detail to define precisely how each protocol should work at each layer. The primary purpose of a reference model is to aid in clearer understanding of the functions and processes necessary for network communications.
The most widely known internetwork reference model was created by the Open Systems Interconnection (OSI) project at the International Organization for Standardization (ISO). It is used for data network design, operation specifications, and troubleshooting. This model is commonly referred to as the OSl model.
Noted
There are two basic types of models that we use to describe the functions that must occur in order for network communications to be successful: ___ models and ___ models.
protocol, reference
This model closely matches the structure of a particular protocol suite. A protocol suite includes the set of related protocols that typically provide all the functionality required for people to communicate with the data network.
Protocol model
The TCP/IP model is a protocol model of this because it describes the functions that occur at each layer of protocols within the TCP/IP suite.
A ___ includes the set of related protocols that typically provide all the functionality required for people to communicate with the data network.
protocol suite
This type of model describes the functions that must be completed at a particular layer, but does not specify exactly how a function should be accomplished.
Reference model
This is not intended to provide a sufficient level of detail to define precisely how each protocol should work at each layer. The primary purpose of this is to aid in clearer understanding of the functions and processes necessary for network communications.
The most widely known internetwork reference model was created by the ___ project at the International Organization for Standardization (ISO).
Open Systems Interconnection (OSI)
It is used for data network design, operation specifications, and troubleshooting. This model is commonly referred to as the OSl model.
OSI Model Layer
7 - Application
The application layer contains protocols used for process-to-process communications.
6 - Presentation
The presentation layer provides for common representation of the data transferred between application layer services.
5 - Session
The session layer provides services to the presentation layer to organize its dialogue and to manage data exchange.
4 - Transport
The transport layer defines services to segment, transfer, and reassemble the data for individual communications between the end devices.
3 - Network
The network layer provides services to exchange the individual pieces of data over the network between identified end devices.
2 - Data Link
The data link layer protocols describe methods for exchanging data frames between devices over a common media.
1 - Physical
The physical layer protocols describe the mechanical, electrical, functional, and procedural means to activate, maintain, and de-activate physical connections for a bit transmission to and from a network device.
Noted
OSI Model Layer
7 - Application
The application layer contains protocols used for process-to-process communications.
6 - Presentation
The presentation layer provides for common representation of the data transferred between application layer services.
5 - Session
The session layer provides services to the presentation layer to organize its dialogue and to manage data exchange.
4 - Transport
The transport layer defines services to segment, transfer, and reassemble the data for individual communications between the end devices.
3 - Network
The network layer provides services to exchange the individual pieces of data over the network between identified end devices.
2 - Data Link
The data link layer protocols describe methods for exchanging data frames between devices over a common media.
1 - Physical
The physical layer protocols describe the mechanical, electrical, functional, and procedural means to activate, maintain, and de-activate physical connections for a bit transmission to and from a network device.
OSI Model Layer
Contains protocols used for process-to-process communications.
7 - Application
OSI Model Layer
Provides for common representation of the data transferred between application layer services.
6 - Presentation
OSI Model Layer
Provides services to the presentation layer to organize its dialogue and to manage data exchange.
5 - Session
OSI Model Layer
Defines services to segment, transfer, and reassemble the data for individual communications between the end devices.
4 - Transport
OSI Model Layer
Provides services to exchange the individual pieces of data over the network between identified end devices.
3 - Network
OSI Model Layer
Protocols describe methods for exchanging data frames between devices over a common media.
2 - Data Link
OSI Model Layer
Protocols describe the mechanical, electrical, functional, and procedural means to activate, maintain, and de-activate physical connections for a bit transmission to and from a network device.
1 - Physical
5.3.5 OSI Model and TCP/IP Model Comparison
Because TCP/IP is the protocol suite in use for internet communications, why do we need to learn the OSI model as well?
The TCP/IP model is a method of visualizing the interactions of the various protocols that make up the TCP/IP protocol suite. It does not describe general functions that are necessary for all networking communications. It describes the networking functions specific to those protocols in use in the TCP/IP protocol suite.
For example, at the network access layer, the TCP/IP protocol suite does not specify which protocols to use when transmitting over a physical medium, nor the method of encoding the signals for transmission. OSI Layers 1 and 2 discuss the necessary procedures to access the media and the physical means to send data over a network.
The protocols that make up the TCP/IP protocol suite can be described in terms of the OSI reference model. The functions that occur at the internet layer in the TCP/IP model are contained in the network layer of the OSI Model, as shown in the figure. The transport layer functionality is the same between both models. However, the network access layer and the application layer of the TCP/IP model are further divided in the OSI model to describe discrete functions that must occur at these layers.
Noted
Application (TCP/IP model)
Application (OSI model)
Presentation (OSI model)
Session (OSI model)
///
Transport (TCP/IP model)
Transport (OSI model)
///
Internet (TCP/IP model)
Network (OSI model)
///
Network Access (TCP/IP model)
Data Link (OSI model)
Physical (OSI model)
The key similarities are in the transport and network layers; however, the two models differ in how they relate to the layers above and below each layer:
- OSI Layer 3, the network layer, maps directly to the TCP/IP internet layer. This layer is used to describe protocols that address and route messages through an internetwork.
- OSI Layer 4, the transport layer, maps directly to the TCP/IP transport layer. This layer describes general services and functions that provide ordered and reliable delivery of data between source and destination hosts.
- The TCP/IP application layer includes several protocols that provide specific functionality to a variety of end user applications. The OSI model Layers 5, 6, and 7 are used as references for application software developers and vendors to produce applications that operate on networks.
- Both the TCP/IP and OSI models are commonly used when referring to protocols at various layers. Because the OSI model separates the data link layer from the physical layer, it is commonly used when referring to these lower layers.
Application (TCP/IP model)
Application (OSI model)
Presentation (OSI model)
Session (OSI model)
///
Transport (TCP/IP model)
Transport (OSI model)
///
Internet (TCP/IP model)
Network (OSI model)
///
Network Access (TCP/IP model)
Data Link (OSI model)
Physical (OSI model)
Noted
5.3.6 Check Your Understanding - Network Communication Models
Which protocol is responsible for guaranteeing reliable delivery?
◯ TCP
◯ IP
◯ Ethernet
◯ HTTP
TCP
Transport Control Protocol (TCP) is responsible for guaranteeing reliable delivery.
5.3.6 Check Your Understanding - Network Communication Models
Which protocol is used by routers to forward messages?
◯ TCP
◯ Ethernet
◯ IP
◯ HTTP
IP
Internet Protocol (IP) is used by routers to forward messages.
5.3.6 Check Your Understanding - Network Communication Models
Which two layers of the OSI Model maps directly as the single network access layer in the TCP/IP model? (Choose two)
▢ session
▢ application
▢ data link
▢ network
▢ physical
▢ transport
▢ presentation
data link
physical
The OSI model data link and network layers correspond to the network access layer in the TCP/IP model.
5.3.6 Check Your Understanding - Network Communication Models
IP addressing occurs at what layer of the OSI Model?
◯ transport
◯ network
◯ session
◯ application
◯ data link
◯ physical
◯ presentation
network
IP addressing occurs at the network layer.
5.4 Communication Principles Summary
Communication Protocol
Protocols are required for computers to properly communicate across the network. These include message format, message size, timing, encoding, encapsulation, and message patterns.
- Message format - When a message is sent, it must use a specific format or structure.
- Message size - The rules that govern the size of the pieces communicated across the network are very strict. They can also be different, depending on the channel used.
- Timing - Timing determines the speed at which the bits are transmitted across the network. It also affects when an individual host can send data and the total amount of data that can be sent in any one transmission.
- Encoding - Messages sent across the network are first converted into bits by the sending host. Each bit is encoded into a pattern of sounds, light waves, or electrical impulses depending on the network media over which the bits are transmitted.
- Encapsulation - Each message transmitted on a network must include a header that contains addressing information that identifies the source and destination hosts. Encapsulation is the process of adding this information to the pieces of data that make up the message.
- Message pattern - Some messages require an acknowledgment before the next message can be sent. This type of request/response pattern is a common aspect of many networking protocols. However, there are other types of messages that may be simply streamed across the network, without concern as to whether they reach their destination.
Noted
5.4 Communication Principles Summary
Communication Standards
Topologies allow us to see the networking using representation of end devices and intermediary devices. How does a device see a network? Think of a device in a bubble. The only thing a device sees is its own addressing information. How does the device know it is on the same network as another device? The answer is network protocols. Most network communications are broken up into smaller data units, or packets.
A standard is a set of rules that determines how something must be done. Networking and internet standards ensure that all devices connecting to the network implement the same set of rules or protocols in the same manner. Using standards, it is possible for different types of devices to send information to each other over the internet.
An internet standard is the end result of a comprehensive cycle of discussion, problem solving, and testing. These different standards are developed, published, and maintained by a variety of organizations. When a new standard is proposed, each stage of the development and approval process is recorded in a numbered RFC document so that the evolution of the standard is tracked. RFCs for internet standards are published and managed by the IETF.
Noted
5.4 Communication Principles Summary
Network Communication Models
Protocols are the rules that govern communications. Successful communication between hosts requires interaction between a number of protocols. Protocols include HTTP, TCP, IP, and Ethernet. These protocols are implemented in software and hardware that are installed on each host and networking device.
The interaction between the different protocols on a device can be illustrated as a protocol stack. A stack illustrates the protocols as a layered hierarchy, with each higher-level protocol depending on the services of the protocols shown in the lower levels. The separation of functions enables each layer in the stack to operate independently of others.
The suite of TCP/IP protocols that are used for internet communications follows the structure of this model:
- Application - Represents data to the user, plus encoding and dialog control
- Transport -Supports communication between various devices across diverse networks
- Internet - Determines the best path through the network
- Network Access - The hardware devices and media that make up the network.
A reference model describes the functions that must be completed at a particular layer but does not specify exactly how a function should be accomplished. The primary purpose of a reference model is to aid in clearer understanding of the functions and processes necessary for network communications.
The most widely known internetwork reference model was created by the OSI project at the International ISO. It is used for data network design, operation specifications, and troubleshooting. This model is commonly referred to as the OSI model.
Noted
5.4 Communication Principles Summary
OSI Model Layer Description
- 7 – Application - The application layer contains protocols used for process-to-process communications.
- 6 – Presentation - The presentation layer provides for common representation of the data transferred between application layer services.
- 5 – Session - The session layer provides services to the presentation layer to organize its dialogue and to manage data exchange.
- 4 – Transport - The transport layer defines services to segment, transfer, and reassemble the data for individual communications between the end devices.
- 3 – Network - The network layer provides services to exchange the individual pieces of data over the network between identified end devices.
- 2 - Data Link - The data link layer protocols describe methods for exchanging data frames between devices over a common media
- 1 – Physical - The physical layer protocols describe the mechanical, electrical, functional, and procedural means to activate, maintain, and de-activate physical connections for a bit transmission to and from a network device.
Noted
5.4.3 Communications Principles Quiz
What is the purpose of the OSI physical layer?
◯ controlling access to media
◯ transmitting bits across the local media
◯ performing error detection on received frames
◯ exchanging frames between nodes over physical network media
transmitting bits across the local media
5.4.3 Communications Principles Quiz
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.
They define how messages are exchanged between the source and the destination.
5.4.3 Communications Principles Quiz
Which three acronyms/initialisms represent standards organizations? (Choose three.)
▢ IANA
▢ TCP/IP
▢ IEEE
▢ IETF
▢ OSI
▢ MAC
IANA
IEEE
IETF
5.4.3 Communications Principles Quiz
What networking term describes a particular set of rules at one layer that govern communication at that layer?
◯ duplex
◯ encapsulation
◯ error checking
◯ protocol
protocol
5.4.3 Communications Principles Quiz
Which layer of the OSI model defines services to segment and reassemble data for individual communications between end devices?
◯ application
◯ presentation
◯ session
◯ transport
◯ network
transport
5.4.3 Communications Principles Quiz
What is the purpose of protocols in data communications?
◯ specifying the bandwidth of the channel or medium for each type of communication
◯ specifying the device operating systems that will support the communication
◯ providing the rules required for a specific type of communication to occur
◯ dictating the content of the message sent during communication
providing the rules required for a specific type of communication to occur
5.4.3 Communications Principles Quiz
Which term refers to the set of rules that define how a network operates?
◯ standard
◯ protocol
◯ model
◯ domain
standard
5.4.3 Communications Principles Quiz
Which three layers of the OSI model make up the application layer of the TCP/IP model? (Choose three.)
▢ data link
▢ network
▢ transport
▢ session
▢ presentation
▢ application
session
presentation
application
5.4.3 Communications Principles Quiz
Which organization publishes and manages the Request for Comments (RFC) documents?
◯ IEEE
◯ ISO
◯ IETF
◯ TIA/EIA
IETF
5.4.3 Communications Principles Quiz
Which two OSI model layers have the same functionality as a single layer of the TCP/IP model? (Choose two.)
▢ data link
▢ network
▢ physical
▢ session
▢ transport
data link
physical
