Check your understanding of communication protocols by choosing the correct answer to the following questions.
1.2 Data Transmission
1.3 Bandwidth and Throughput
1.4 Communications in a Connected World Summary
2.1 Clients and Servers
2.2 Network Components
2.3 ISP Connectivity Options
2.4 Network Components, Types, and Connections Summary
3.0 Introduction
3.1 Wireless Networks
3.2 Mobile Device Connectivity
3.3 Wireless and Mobile Networks Summary
4.0 Introduction
4.1 Home Network Basics
4.2 Network Technologies in the Home
4.3 Wireless Standards
4.4 Set Up a Home Router
4.5 Build a Home Network Summary
5.0 Introduction
5.1 Communication Protocols
5.2 Communication Standards
5.3 Network Communication Models
5.4 Communication Principles Summary
The Networking Basics course teaches the fundamentals of networking by covering the basic concepts and skills needed to set up and manage your small office or home office (SOHO) network. The learner is presented with an engaging and exploratory view of networks, the devices that comprise them, how they work, and basic troubleshooting tools and techniques. The goal of this course is to provide the learner with an engaging, exploratory view of networks, including the internet. Upon completion of the Networking Basics course, students will be able to perform the following tasks:
There are a number of tools and resources that are available to you that will help you in your journey as you develop your networking skills and prepare for job opportunities.
Packet Tracer
Packet Tracer simulates the internal workings of a network and is used in this course.
If you are new to Packet Tracer, take this FREE, short, online course now: Getting Started with Cisco Packet Tracer.
You can use your smartphone, tablet, or desktop to access your course; however, Packet Tracer activities, as well as some other activities, quizzes, and exams are best experienced using a PC.
Lab Environment
No equipment is necessary
Resources Available to You
Skills for All frequently asked questions can be found at https://skillsforall.com/help, or by clicking Help in the top navigation bar. For Packet Tracer downloading help, visit https://skillsforall.com/resources/lab-downloads and scroll down to Learning Resources.
You can find additional FAQs by visiting our virtual assistant, Morgan. Click the chat icon in the top right corner to choose from a list of topics or enter your question. Morgan’s help includes information about Packet Tracer, certificates, and badging.
To obtain and install your copy of Cisco Packet Tracer, please follow the instructions from the link below: https://skillsforall.com/resources/lab-downloads
Module Title: Communications in a Connected World
Module Objective: Explain important concepts in network communication.
Topic Title | Topic Objective |
---|---|
Network Types | Explain the concept of a network. |
Data Transmission | Describe network data. |
Bandwidth and Throughput | Explain network transmission speed and capacity. |
“Hey Shad, are you online?” “Of course, I am!” How many of us still think about whether or not we are “online”? We expect our devices, cell phones, tablets, laptops and desktop computers to always be connected to the global internet. We use this network to interact with our friends, shop, share pictures and experiences, and learn. The internet has become such a part of everyday life that we almost take it for granted.
Normally, when people use the term internet, they are not referring to the physical connections in the real world. Rather, they tend to think of it as a formless collection of connections. It is the “place” people go to find or share information.
“Hey Shad, are you online?” “Of course, I am!” How many of us still think about whether or not we are “online”? We expect our devices, cell phones, tablets, laptops and desktop computers to always be connected to the global internet. We use this network to interact with our friends, shop, share pictures and experiences, and learn. The internet has become such a part of everyday life that we almost take it for granted.
Normally, when people use the term internet, they are not referring to the physical connections in the real world. Rather, they tend to think of it as a formless collection of connections. It is the “place” people go to find or share information.
The internet is not owned by any individual or group. The internet is a worldwide collection of interconnected networks (internetwork or internet for short), cooperating with each other to exchange information using common standards. Through telephone wires, fiber-optic cables, wireless transmissions, and satellite links, internet users can exchange information in a variety of forms, as shown in the figure.
Everything that you access online is located somewhere on the global internet. Social media sites, multiplayer games, messaging centers that provide email, online courses — all of these internet destinations are connected to local networks that send and receive information through the internet.
Think about all of the interactions that you have during the day which require you to be online.
The internet is not owned by any individual or group. The internet is a worldwide collection of interconnected networks (internetwork or internet for short), cooperating with each other to exchange information using common standards. Through telephone wires, fiber-optic cables, wireless transmissions, and satellite links, internet users can exchange information in a variety of forms, as shown in the figure.
Everything that you access online is located somewhere on the global internet. Social media sites, multiplayer games, messaging centers that provide email, online courses — all of these internet destinations are connected to local networks that send and receive information through the internet.
Think about all of the interactions that you have during the day which require you to be online.
Local networks come in all sizes. They can range from simple networks consisting of two computers, to networks connecting hundreds of thousands of devices. Networks installed in small offices, or homes and home offices, are referred to as small office/home office (SOHO) networks. SOHO networks let you share resources such as printers, documents, pictures, and music, between a few local users.
In business, large networks can be used to advertise and sell products, order supplies, and communicate with customers. Communication over a network is usually more efficient and less expensive than traditional forms of communication, such as regular mail or long distance phone calls. Networks allow for rapid communication such as email and instant messaging, and provide consolidation and access to information stored on network servers.
Business and SOHO networks usually provide a shared connection to the internet. The internet is considered a “network of networks” because it is literally made up of thousands of local networks that are connected to each other.
Click each button for more information.
The internet connects more computing devices than just desktop and laptop computers. There are devices all around that you may interact with on a daily basis that are also connected to the internet. These include mobile devices, home devices, and a variety of other connected devices.
Click below to learn more about mobile devices.
Many of the things in your home can also be connected to the internet so that they can be monitored and configured remotely.
Click below to learn more about connected household devices.
There are also many connected devices found in the world outside your home that provide convenience and useful, or even vital, information.
Click below to learn more about these commonly found connected devices.
Check your understanding of network types by choosing the correct answer to the following questions.
Did you know that computers and networks only work with binary digits, zeros and ones? It can be difficult to imagine that all of our data is stored and transmitted as a series of bits. Each bit can only have one of two possible values, 0 or 1. The term bit is an abbreviation of “binary digit” and represents the smallest piece of data. Humans interpret words and pictures, computers interpret only patterns of bits.
A bit is stored and transmitted as one of two possible discrete states. This can include two directions of magnetization, two distinct voltage or current levels, two distinct levels of light intensity, or any other physical system of two discrete states. For example, a light switch can be either On or Off; in binary representation, these states would correspond to 1 and 0 respectively.
Every input device (mouse, keyboard, voice-activated receiver) will translate human interaction into binary code for the CPU to process and store. Every output device (printer, speakers, monitors, etc.) will take binary data and translate it back into human recognizable form. Within the computer itself, all data is processed and stored as binary.
Computers use binary codes to represent and interpret letters, numbers and special characters with bits. A commonly used code is the American Standard Code for Information Interchange (ASCII). With ASCII, each character is represented by eight bits. For example:
Each group of eight bits, such as the representations of letters and numbers, is known as a byte.
Codes can be used to represent almost any type of information digitally including computer data, graphics, photos, voice, video, and music.
In the figure, enter up to five characters in the Characters field, then click the Show Me button to see the ASCII bit translation. Click Reset to enter a different group of characters.
After the data is transformed into a series of bits, it must be converted into signals that can be sent across the network media to its destination. Media refers to the physical medium on which the signals are transmitted. Examples of media are copper wire, fiber-optic cable, and electromagnetic waves through the air. A signal consists of electrical or optical patterns that are transmitted from one connected device to another. These patterns represent the digital bits (i.e. the data) and travel across the media from source to destination as either a series of pulses of electricity, pulses of light, or radio waves. Signals may be converted many times before ultimately reaching the destination, as corresponding media changes between source and destination.
There are three common methods of signal transmission used in networks:
Click Play in the figure to see an animation of the three types of signal transmissions.
In most homes and small businesses, network signals are transmitted across copper wires (cables) or Wi-Fi enabled wireless connections. Larger networks employ fiber-optic cables in order to reliably carry signals for longer distances.
Streaming a movie or playing a multiplayer game requires reliable, fast connections. To support these “high bandwidth” applications, networks have to be capable of transmitting and receiving bits at a very high rate.
Different physical media support the transfer of bits at different speeds. The rate of data transfer is usually discussed in terms of bandwidth and throughput.
Bandwidth is the capacity of a medium to carry data. Digital bandwidth measures the amount of data that can flow from one place to another in a given amount of time. Bandwidth is typically measured in the number of bits that (theoretically) can be sent across the media in a second. Common bandwidth measurements are as follows:
Physical media properties, current technologies, and the laws of physics all play a role in determining available bandwidth.
The table shows the commonly used units of measure for bandwidth.
Unit of Bandwidth | Abbreviation | Equivalence |
---|---|---|
Bits per second | bps | 1 bps = fundamental unit of bandwidth |
Kilobits per second | Kbps | 1 Kbps = 1,000 bps = 103 bps |
Megabits per second | Mbps | 1 Mbps = 1,000,000 bps = 106 bps |
Gigabits per second | Gbps | 1 Gbps = 1,000,000,000 bps = 109 bps |
Terabits per second | Tbps | 1 Tbps = 1,000,000,000,000 bps = 1012 bps |
Like bandwidth, throughput is the measure of the transfer of bits across the media over a given period of time. However, due to a number of factors, throughput does not usually match the specified bandwidth. Many factors influence throughput including:
Latency refers to the amount of time, including delays, for data to travel from one given point to another.
Throughput measurements do not take into account the validity or usefulness of the bits being transmitted and received. Many messages received through the network are not destined for specific user applications. An example would be network control messages that regulate traffic and correct errors.
In an internetwork or network with multiple segments, throughput cannot be faster than the slowest link of the path from sending device to the receiving device. Even if all or most of the segments have high bandwidth, it will only take one segment in the path with lower bandwidth to create a slowdown of the throughput of the entire network.
There are many online speed tests that can reveal the throughput of an internet connection.
Check your understanding of bandwidth and throughput by choosing the correct answer to the following questions.
Network Types
The internet is not owned by any individual or group. The internet is a worldwide collection of interconnected networks (internetwork or internet for short), cooperating with each other to exchange information using common standards. Through telephone wires, fiber-optic cables, wireless transmissions, and satellite links, internet users can exchange information in a variety of forms.
Small home networks connect a few computers to each other and to the internet. The SOHO network allows computers in a home office or a remote office to connect to a corporate network, or access centralized, shared resources. Medium to large networks, such as those used by corporations and schools, can have many locations with hundreds or thousands of interconnected hosts. The internet is a network of networks that connects hundreds of millions of computers world-wide.
There are devices all around that you may interact with on a daily basis that are also connected to the internet. These include mobile devices such as smartphones, tablets, smartwatches, and smart glasses. Things in your home can be connected to the internet such as a security system, appliances, your smart TV, and your gaming console. Outside your home there are smart cars, RFID tags, sensors and actuators, and even medical devices which can be connected.
Data Transmission
The following categories are used to classify types of personal data:
The term bit is an abbreviation of “binary digit” and represents the smallest piece of data. Each bit can only have one of two possible values, 0 or 1.
There are three common methods of signal transmission used in networks:
Bandwidth and Throughput
Bandwidth is the capacity of a medium to carry data. Digital bandwidth measures the amount of data that can flow from one place to another in a given amount of time. Bandwidth is typically measured in the number of bits that (theoretically) can be sent across the media in a second. Common bandwidth measurements are as follows:
Throughput does not usually match the specified bandwidth. Many factors influence throughput including:
Latency refers to the amount of time, including delays, for data to travel from one given point to another.
Maybe you don’t work in a hospital, but if you are here now it’s because, like Kishori, you use computers and want to know more about networks. Did you know that the internet is a massive network of networks that are connected, either directly or indirectly, to each other? It’s kind of like this web that I live in. One part can be broken but my web doesn’t fall apart; I can fix it, and even make it stronger. Would you like to be able to do that for your network?
What is the internet?
What is an example of a binary value from everyday life?
Which category of network components includes wires and cables used in a wired network?
What type of device is able to create physical movement?
What are three options for signal transmission on a network? (Choose three.)
Who owns the internet?
Which type of connected device is placed on objects to track and monitor them?
A byte consists of how many bits?
Which two numbers are possible values of a bit? (Choose two.)
What measurement is used to indicate thousands of bits per second?
What type of network must a home user access in order to do online shopping?
Kishori does not yet understand network infrastructure device roles in the network, including end devices, intermediate devices, and network media. When she first started her nursing career, she was writing patient medical notes in a paper notebook! At home, Kishori only has a laptop, a smartphone, and a tablet. This makes her most familiar with end devices, or hosts. She understands that those devices are connected to the internet somehow through that box in the corner of her living room. At work she uses a laptop, a desktop, a printer, and other network-connected hospital equipment. She wants to learn more about network components and how they all connect.
Kishori leaves her patient’s room, sets down her laptop, and continues her work on the desktop computer at the nursing station. She wonders how the electronic notes she just took on the laptop appear on the patient’s record on the desktop computer. How are they connected? How does the computer reach the internet in the first place? Kishori has a lot to learn, and you might too! Take this module to learn more.
Module Title: Network Components, Types, and Connections
Module Objective: Explain network types, components, and connections.
Topic Title | Topic Objective |
---|---|
Clients and Servers | Explain the roles of clients and servers in a network. |
Network Components | Explain the roles of network infrastructure devices. |
ISP Connectivity Options | Describe ISP connectivity options. |
Press the Play button to watch the video.
All computers connected to a network that participate directly in network communication are classified as hosts. Hosts can send and receive messages on the network. In modern networks, computer hosts can act as a client, a server, or both, as shown in the figure. The software installed on the computer determines which role the computer plays.
Servers are hosts that have software installed which enable them to provide information, like email or web pages, to other hosts on the network. Each service requires separate server software. For example, a host requires web server software in order to provide web services to the network. Every destination that you visit online is provided to you by a server located somewhere on a network that is connected to the global internet.
Clients are computer hosts that have software installed that enables the hosts to request and display the information obtained from the server. An example of client software is a web browser, such as Internet Explorer, Safari, Mozilla Firefox, or Chrome.
Servers are hosts that have software installed which enable them to provide information, like email or web pages, to other hosts on the network. Each service requires separate server software. For example, a host requires web server software in order to provide web services to the network. Every destination that you visit online is provided to you by a server located somewhere on a network that is connected to the global internet.
Client and server software usually run on separate computers, but it is also possible for one computer to run both client and server software at the same time. In small businesses and homes, many computers function as the servers and clients on the network. This type of network is called a peer-to-peer (P2P) network.
The simplest P2P network consists of two directly connected computers using either a wired or wireless connection. Both computers are then able to use this simple network to exchange data and services with each other, acting as either a client or a server as necessary.
Multiple PCs can also be connected to create a larger P2P network, but this requires a network device, such as a switch, to interconnect the computers.
The main disadvantage of a P2P environment is that the performance of a host can be slowed down if it is acting as both a client and a server at the same time. The figure lists some of the advantages and disadvantages of peer-to-peer networks.
In larger businesses, because of the potential for high amounts of network traffic, it is often necessary to have dedicated servers to support the number of service requests.
The advantages and disadvantages of P2P networking are summarized in the figure.
Client and server software usually run on separate computers, but it is also possible for one computer to run both client and server software at the same time. In small businesses and homes, many computers function as the servers and clients on the network. This type of network is called a peer-to-peer (P2P) network.
The simplest P2P network consists of two directly connected computers using either a wired or wireless connection. Both computers are then able to use this simple network to exchange data and services with each other, acting as either a client or a server as necessary.
Multiple PCs can also be connected to create a larger P2P network, but this requires a network device, such as a switch, to interconnect the computers.
The main disadvantage of a P2P environment is that the performance of a host can be slowed down if it is acting as both a client and a server at the same time. The figure lists some of the advantages and disadvantages of peer-to-peer networks.
In larger businesses, because of the potential for high amounts of network traffic, it is often necessary to have dedicated servers to support the number of service requests.
The advantages and disadvantages of P2P networking are summarized in the figure.
The advantages of peer-to-peer networking:
The disadvantages of peer-to-peer networking:
A P2P application allows a device to act as both a client and a server within the same communication, as shown in the figure. In this model, every client is a server and every server is a client. P2P applications require that each end device provide a user interface and run a background service.
Some P2P applications use a hybrid system where resource sharing is decentralized, but the indexes that point to resource locations are stored in a centralized directory. In a hybrid system, each peer accesses an index server to get the location of a resource stored on another peer.
A P2P application allows a device to act as both a client and a server within the same communication, as shown in the figure. In this model, every client is a server and every server is a client. P2P applications require that each end device provide a user interface and run a background service.
Some P2P applications use a hybrid system where resource sharing is decentralized, but the indexes that point to resource locations are stored in a centralized directory. In a hybrid system, each peer accesses an index server to get the location of a resource stored on another peer.
Both clients can simultaneously send and receive messages.
A computer with server software can provide services simultaneously to one or many clients, as shown in the figure.
Additionally, a single computer can run multiple types of server software. In a home or small business, it may be necessary for one computer to act as a file server, a web server, and an email server.
A single computer can also run multiple types of client software. There must be client software for every service required. With multiple clients installed, a host can connect to multiple servers at the same time. For example, a user can check email and view a web page while instant messaging and listening to internet radio.
A computer with server software can provide services simultaneously to one or many clients, as shown in the figure.
Additionally, a single computer can run multiple types of server software. In a home or small business, it may be necessary for one computer to act as a file server, a web server, and an email server.
A single computer can also run multiple types of client software. There must be client software for every service required. With multiple clients installed, a host can connect to multiple servers at the same time. For example, a user can check email and view a web page while instant messaging and listening to internet radio.
Check your understanding of clients and servers by choosing the correct answer to the following questions.
The path that a message takes from its source to destination can be as simple as a single cable connecting one computer to another, or as complex as a network that literally spans the globe. This network infrastructure is the platform that supports the network. It provides the stable and reliable channel over which our communications can occur.
The network infrastructure contains three categories of hardware components, as shown in the figure:
The path that a message takes from its source to destination can be as simple as a single cable connecting one computer to another, or as complex as a network that literally spans the globe. This network infrastructure is the platform that supports the network. It provides the stable and reliable channel over which our communications can occur.
The network infrastructure contains three categories of hardware components, as shown in the figure:
Devices and media are the physical elements, or hardware, of the network. Hardware is often the visible components of the network platform such as a laptop, PC, switch, router, wireless access point, or the cabling used to connect the devices. Occasionally, some components may not be so visible. In the case of wireless media, messages are transmitted through the air using invisible radio frequencies or infrared waves.
Make a list of the network infrastructure components installed in your home network. Include the cables or wireless access points that provide your network connections.
The network devices that people are most familiar with are called end devices, or hosts. These devices form the interface between users and the underlying communication network.
Some examples of end devices are as follows:
An end device (or host) is either the source or destination of a message transmitted over the network, as shown in the animation. In order to uniquely identify hosts, addresses are used. When a host initiates communication, it uses the address of the destination host to specify where the message should be sent.
Click Play in the figure to see an animation of data flowing through a network.
The network devices that people are most familiar with are called end devices, or hosts. These devices form the interface between users and the underlying communication network.
Some examples of end devices are as follows:
An end device (or host) is either the source or destination of a message transmitted over the network, as shown in the animation. In order to uniquely identify hosts, addresses are used. When a host initiates communication, it uses the address of the destination host to specify where the message should be sent.
Click Play in the figure to see an animation of data flowing through a network.
Check your understanding of network components by choosing the correct answer to the following questions.
An Internet Service Provider (ISP) provides the link between the home network and the internet. An ISP can be the local cable provider, a landline telephone service provider, the cellular network that provides your smartphone service, or an independent provider who leases bandwidth on the physical network infrastructure of another company.
Many ISPs also offer additional services to their contract subscribers, as shown in the figure. These services can include email accounts, network storage, and website hosting and automated backup or security services.
ISPs are critical to communications across the global internet. Each ISP connects to other ISPs to form a network of links that interconnect users all over the world. ISPs are connected in a hierarchical manner that ensures that internet traffic generally takes the shortest path from the source to the destination.
The internet backbone is like an information super highway that provides high-speed data links to connect the various service provider networks in major metropolitan areas around the world. The primary medium that connects the internet backbone is fiber-optic cable. This cable is typically installed underground to connect cities within continents. Fiber-optic cables also run under the sea to connect continents, countries, and cities.
An Internet Service Provider (ISP) provides the link between the home network and the internet. An ISP can be the local cable provider, a landline telephone service provider, the cellular network that provides your smartphone service, or an independent provider who leases bandwidth on the physical network infrastructure of another company.
Many ISPs also offer additional services to their contract subscribers, as shown in the figure. These services can include email accounts, network storage, and website hosting and automated backup or security services.
ISPs are critical to communications across the global internet. Each ISP connects to other ISPs to form a network of links that interconnect users all over the world. ISPs are connected in a hierarchical manner that ensures that internet traffic generally takes the shortest path from the source to the destination.
The internet backbone is like an information super highway that provides high-speed data links to connect the various service provider networks in major metropolitan areas around the world. The primary medium that connects the internet backbone is fiber-optic cable. This cable is typically installed underground to connect cities within continents. Fiber-optic cables also run under the sea to connect continents, countries, and cities.
Most home network users do not connect to their service providers with fiber-optic cables. The figure illustrates common connection options for small office and home users. The two most common methods are as follows:
Most home network users do not connect to their service providers with fiber-optic cables. The figure illustrates common connection options for small office and home users. The two most common methods are as follows:
In metropolitan areas, many apartments and small offices are being connected directly with fiber-optic cables. This enables an internet service provider to provide higher bandwidth speeds and support more services such as internet, phone, and TV.
The choice of connection varies depending on geographical location and service provider availability.
In metropolitan areas, many apartments and small offices are being connected directly with fiber-optic cables. This enables an internet service provider to provide higher bandwidth speeds and support more services such as internet, phone, and TV.
The choice of connection varies depending on geographical location and service provider availability.
All computers connected to a network that participate directly in network communication are classified as hosts. Hosts can send and receive messages on the network. In modern networks, computer hosts can act as a client, a server, or both. The software installed on the computer determines which role the computer plays.
Client and server software usually run on separate computers, but it is also possible for one computer to run both client and server software at the same time. In small businesses and homes, many computers function as the servers and clients on the network. This type of network is called a P2P network. In larger businesses, because of the potential for high amounts of network traffic, it is often necessary to have dedicated servers to support the number of service requests. P2P networks are easy to set up, less complex, lower in cost, and can be used for simple tasks such as transferring files and sharing printers. However, there is no centralized administration. They have less security, are not scalable, and can perform slower.
Network Components
There are symbols that represent various types of networking equipment. The network infrastructure is the platform that supports the network. It provides the stable and reliable channel over which our communications can occur. The network infrastructure contains three categories of hardware components: end devices, intermediate devices, and network media. Hardware is often the visible components of the network platform such as a laptop, PC, switch, router, wireless access point, or the cabling used to connect the devices. Components that are not visible include wireless media.
End devices, or hosts, form the interface between users and the underlying communication network. Some examples of end devices include:
ISP Connectivity Options
An ISP provides the link between the home network and the internet. An ISP can be the local cable provider, a landline telephone service provider, the cellular network that provides your smartphone service, or an independent provider who leases bandwidth on the physical network infrastructure of another company. Each ISP connects to other ISPs to form a network of links that interconnect users all over the world. ISPs are connected in a hierarchical manner that ensures that internet traffic generally takes the shortest path from the source to the destination.
The interconnection of ISPs that forms the backbone of the internet is a complex web of fiber-optic cables with expensive networking switches and routers that direct the flow of information between source and destination hosts.
For a home user, connecting to the ISP is a fairly uncomplicated process. This is the most common connection option. It consists of using a wireless integrated router to connect to the ISP. The router includes a switch to connect wired hosts and a wireless AP to connect wireless hosts. The router also provides client IP addressing information and security for inside hosts. The two most common methods are cable and DSL. Other options include cellular, satellite, and dial-up telephone.
Have you ever ordered a piece of furniture that you had to assemble yourself? The box has all the pieces and parts that you need along with the assembly instructions. It helps you to look at all these items while you read through the instructions. Think of your network. Did you know what all the different devices and connection types were before you took this module? Do you look at these pieces and parts differently now?
Kishari has just ended her 10-hour shift at the hospital. As she is walking to her car, her mobile phone rings. It is her son, Shridhar, calling to remind her to pick up the dinner he ordered. While they are verifying their plans, Kishari gets into her car and starts the engine. Her conversation then transfers from her mobile phone to her speakers in her car. She confirms that she will pick up the food and that she will see him in an hour. Before she drives away, she does an internet search for the restaurant and clicks the directions link. She listens to the directions coming through her speakers. “Your destination is on the left.” She purchases the food and drives home. While Kishari and Shridhar enjoy their dinner, Kishari tells Shridhar how she is starting to think about all of this technology at home and at work. She knows how to use it but she does not understand how it works. She gives him the example of mobile phone. Today she answered calls, texted, did an internet search, and used it for driving directions. How does it do all of this? How does the phone connect to all of these things? Shridhar is familiar with the different types of networks used by mobile devices. Shridhar explains the 4G/5G mobile network, GPS, Bluetooth, NFC, and Wi-Fi.
If you do not have a friend or family member like Shridhar to explain this to you, do not worry! In this module, you will learn about the various ways mobile devices communicate. Ready to learn more?
Module Title: Wireless and Mobile Networks
Module Objective: Configure mobile device for wireless access.
Topic Title | Topic Objective |
---|---|
Wireless Networks | Describe the different types of networks used by cell phones and mobile devices. |
Mobile Device Connectivity | Configure mobile devices for wireless connectivity. |
In addition to the GSM and 4G/5G transmitters and receivers, smartphones make connections in a variety of ways.
Click below to learn more about the different ways that smartphones make connections.
GPS
Global Positioning System
The GPS uses satellites to transmit signals that cover the globe. The smartphone can receive these signals and calculate the phone’s location to an accuracy of within 10 meters.
Wi-Fi transmitters and receivers located within the smartphone enable the phone to connect to local networks and the internet. In order to receive and send data on a Wi-Fi network, the phone needs to be within the range of the signal from a wireless network access point. Wi-Fi networks are usually privately owned but often provide guest or public access hotspots. A hotspot is an area where Wi-Fi signals are available. Wi-Fi network connections on the phone are similar to the network connections on a laptop computer.
Bluetooth is a low-power, shorter range wireless technology that is intended to replace wired connectivity for accessories such as speakers, headphones, and microphones. Bluetooth can also be used to connect a smartwatch to a smartphone. Because Bluetooth technology can be used to transmit both data and voice, it can be used to create small local networks. Bluetooth is wireless technology that allows devices to communicate over short distances. Multiple devices can be connected at the same time with Bluetooth.
NFC
Near Field Communication (NFC) is a wireless communication technology that enables data to be exchanged by devices that are in very close proximity to each other, usually less than a few centimeters. For example, NFC can be used to connect a smartphone and a payment system. NFC uses electromagnetic fields to transmit data.
Mobile devices give us the freedom to work, learn, play, and communicate wherever we want. People using mobile devices do not need to be tied to a physical location to send and receive voice, video, and data communications. In addition, wireless facilities, such as internet cafes, are available in many countries. College campuses use wireless networks to allow students to sign up for classes, watch lectures, and submit assignments in areas where physical connections to the network are unavailable. With mobile devices becoming more powerful, many tasks that needed to be performed on large computers connected to physical networks can now be completed using mobile devices on wireless networks.
Almost all mobile devices are capable of connecting to Wi-Fi networks. It is advisable to connect to Wi-Fi networks when possible because data used over Wi-Fi does not count against the cellular data plan. Also, because Wi-Fi radios use less power than cellular radios, connecting to Wi-Fi networks conserves battery power. Like other Wi-Fi-enabled devices, it is important to use security when connecting to Wi-Fi networks. These precautions should be taken to protect Wi-Fi communications on mobile devices:
Two of the most popular operating systems for mobile devices are Android and Apple iOS. Each operating system has settings that enable you to configure your device to connect to wireless networks.
Click below for an example of how to turn Wi-Fi on and off on Android and iOS devices.
To connect an Android or iOS device when it is within the coverage range of a Wi-Fi network, turn on Wi-Fi and the device then searches for all available Wi-Fi networks and displays them in a list. Touch a Wi-Fi network in the list to connect. Enter a password if needed.
When a mobile device is out of the range of the Wi-Fi network, it attempts to connect to another Wi-Fi network in range. If no Wi-Fi networks are in range, the mobile device connects to the cellular data network. When Wi-Fi is on, it will automatically connect to any Wi-Fi network that it has connected to previously. If the network is new, the mobile device either displays a list of available networks that can be used or asks if it should connect to it.
If your mobile device does not prompt to connect to a Wi-Fi network, the network SSID broadcast may be turned off, or the device may not be set to connect automatically. Manually configure the Wi-Fi settings on the mobile device. Remember that SSIDs and passphrases must be typed exactly as entered on the wireless router setup or the device will not connect properly, as shown in the figure. SSID is the name assigned to a wireless network. Passphrase is what we normally use as the “wireless password”.
To connect to a Wi-Fi network manually on an Android device, follow these steps:
Step 1. Select Settings > Add network.
Step 2. Enter the network SSID.
Step 3. Touch Security and select a security type.
Step 4. Touch Password and enter the password.
Step 5. Touch Save.
Operating systems for mobile devices are updated frequently and may be customized by the device manufacturer. The commands listed above may not be exactly the same on your device. There are online manuals for every type of device which are usually accessible from the website of the manufacturer.
To connect to a Wi-Fi network manually on an iOS device, follow these steps:
Step 1. Select Settings > Wi-Fi > Other.
Step 2. Enter the network SSID.
Step 3. Touch Security and select a security type.
Step 4. Touch Other Network.
Step 5. Touch Password and enter the password.
Step 6. Touch Join.
Cellular data plans are offered by most cell phone carriers, but the bandwidth limitations and charges for usage vary widely by carrier, and by plan within carriers. As a result, many mobile device users only use their cellular data plans when Wi-Fi service is not available.
Click below for an example of how to turn cellular data on and off on Android and iOS devices.
Mobile devices are preprogrammed to use a Wi-Fi network for internet if one is available and the device can connect to the access point and receive an IP address. If no Wi-Fi network is available, the device uses the cellular data capability if it is configured. Most of the time, transitions from one network to another are not obvious to the user. For example, as a mobile device moves from an area of 4G coverage to 3G coverage, the 4G radio shuts off and turns on the 3G radio. Connections are not lost during this transition.
Press the Play button to watch the video.
Mobile devices connect using many different methods. Cellular and Wi-Fi can be difficult to configure, and require extra equipment such as towers and access points. Cable connections are not always practical when connecting headsets or speakers. Bluetooth technology provides a simple way for mobile devices to connect to each other and to wireless accessories. Bluetooth is wireless, automatic, and uses very little power, which helps conserve battery life. Up to eight Bluetooth devices can be connected together at any one time.
These are some examples of how devices use Bluetooth:
Bluetooth pairing occurs when two Bluetooth devices establish a connection to share resources. In order for the devices to pair, the Bluetooth radios are turned on, and one device begins searching for other devices. Other devices must be set to discoverable mode, also called visible, so that they can be detected. When a Bluetooth device is in discoverable mode, it transmits the following information when another Bluetooth device requests it:
During the pairing process, a personal identification number (PIN) may be requested to authenticate the pairing process. The PIN is often a number, but can also be a numeric code or passkey. The PIN is stored using pairing services, so it does not have to be entered the next time the device tries to connect. This is convenient when using a headset with a smart phone, because they are paired automatically when the headset is turned on and within range.
To pair a Bluetooth device with an Android device, follow these steps:
Step 1. Follow the instructions for your device to place it in discoverable mode.
Step 2. Check the instructions for your device to find the connection PIN.
Step 3. Select Settings > Wireless and networks.
Step 4. Touch Bluetooth to turn it on.
Step 5. Touch the Bluetooth tab.
Step 6. Touch Scan for devices.
Step 7. Touch the discovered device to select it.
Step 8. Type the PIN.
Step 9. Touch the device name again to connect to it.
To pair a Bluetooth device with an iOS device, follow these steps:
Step 1. Follow the instructions for your device to place it in discoverable mode.
Step 2. Check the instructions for your device to find the connection PIN.
Step 3. Select Settings > Bluetooth.
Step 4. Touch Bluetooth to turn it on.
Step 5. Touch the discovered device to select it.
Step 6. Type the PIN.
Remember that mobile device operating systems are updated frequently. Always refer to the documentation of the manufacturer for your specific model device for the latest command reference.
Now that you have reviewed the steps to configure and verify your Wi-Fi, cellular, and Bluetooth access, explore these settings on your own phone. If you have access to a Bluetooth device, like headphones or a speaker, connect it to your phone. Notice that you can be using all three of these wireless services simultaneously, each serving a different role. You could be listening to music (Bluetooth), researching on the internet (Wi-Fi), and receiving text messages (cellular).
Click below to learn more about the different ways that smartphones make connections.
Wireless Network
Mobile phones use radio waves to transmit voice signals to antennas mounted on towers located in specific geographic areas. When a telephone call is made, the voice signal is relayed from one tower to another tower until it is delivered to its destination. This type of network is used when you make a phone call to another mobile phone or to a wired telephone. It is also used to send text messages directly from the phone. The most common type of cellular telephone network is called a GSM network. The abbreviations 3G, 4G, 4G-LTE, and 5G are used to describe enhanced cell phone networks that are optimized for the fast transmission of data. Currently, 4G still dominates as the current mobile network used by most phones.
In addition to the GSM and 4G/5G transmitters and receivers, smartphones make connections in a variety of ways.
Wi-Fi transmitters and receivers located within the smartphone enable the phone to connect to local networks and the internet. Wi-Fi networks are usually privately owned but often provide guest or public access hotspots. A hotspot is an area where Wi-Fi signals are available.
Bluetooth is wireless technology that allows devices to communicate over short distances. Multiple devices can be connected at the same time with Bluetooth.
NFC is a wireless communication technology that enables data to be exchanged by devices that are in very close proximity to each other, usually less than a few centimeters.
Mobile Device Connectivity
Almost all mobile devices are capable of connecting to Wi-Fi networks. These precautions should be taken to protect Wi-Fi communications on mobile devices:
Two of the most popular operating systems for mobile devices are Android and Apple iOS. Mobile devices are preprogrammed to use a Wi-Fi network for the internet if one is available, and the device can connect to the access point and receive an IP address. If no Wi-Fi network is available, the device uses the cellular data capability if it is configured.
Bluetooth technology provides a simple way for mobile devices to connect to each other and to wireless accessories. Bluetooth is wireless, automatic, and uses very little power, which helps conserve battery life. Some examples of devices that use Bluetooth include hands-free headsets, keyboards, a mouse, stereo controls, car speakerphones, and mobile speakers.
Bluetooth pairing occurs when two Bluetooth devices establish a connection to share resources. In order for the devices to pair, the Bluetooth radios are turned on, and one device begins searching for other devices. Other devices must be set to discoverable mode, also called visible, so that they can be detected.
When a Bluetooth device is in discoverable mode, it transmits the following information when another Bluetooth device requests it:
During the pairing process, a PIN may be requested to authenticate the pairing process.
I find it fascinating that that you can send and receive data without plugging one device into another using a cable. I am going to get a tablet so I can take this course while I am at the beach! How many ways does your tablet or smartphone communicate when you are away from your home network?
Kishori and Shridhar are washing the dishes after dinner. Kishori is watching a favorite movie on her tablet while putting the dishes away. She asks Shridhar if her tablet works exactly as her mobile phone does. He explains that there are some tablets that do use a mobile network, but that her tablet is works on Wi-Fi network in her house. She tells him that she knows it must come in from that box in the corner of the living room. That is all she knows!
Shridhar explains that the box in the corner is a home router. The router is connected to the internet. Home routers typically have two primary types of ports: ethernet ports and internet ports. In addition to the wired ports, many home routers include a radio antenna and a built-in wireless access point. Kishori mostly uses wireless at home. Now Shridhar is worried about his mother’s wireless security. Since she did not know what the router was, she probably did not change her default password on the router! Shridhar logs into the router and makes some changes to keep Kishori’s network and devices safer.
Have you ever set up a router? Have you thought about having secure communications over wireless devices? This module will give you the knowledge to build a home network and configure wireless devices for secure communication.
Module Title: Build a Home Network
Module Objective: Configure an integrated wireless router and wireless client to connect securely to the internet.
Topic Title | Topic Objective |
---|---|
Home Network Basics | Describe the components required to build a home network. |
Network Technologies in the Home | Describe wired and wireless network technologies. |
Wireless Standards | Describe Wi-Fi. |
Set Up a Home Router | Configure wireless devices for secure communications. |
The wireless technologies most frequently used in home networks are in the unlicensed 2.4 GHz and 5 GHz frequency ranges.
Bluetooth is a technology that makes use of the 2.4 GHz band. It is limited to low-speed, short-range communications, but has the advantage of communicating with many devices at the same time. This one-to-many communication has made Bluetooth technology the preferred method for connecting computer peripherals such as wireless mice, keyboards and printers. Bluetooth is a good method for transmitting audio to speakers or headphones.
Other technologies that use the 2.4 GHz and 5 GHz bands are the modern wireless LAN technologies that conform to the various IEEE 802.11 standards. Unlike Bluetooth technology, 802.11 devices transmit at a much higher power level giving them a great range and improved throughput. Certain areas of the electromagnetic spectrum can be used without a permit.
The figure shows where wireless technologies exist on the electromagnetic spectrum.
The figure shows where wireless technologies exist on the electromagnetic spectrum.
Although many home network devices support wireless communications, there are still a few applications where devices benefit from a wired switch connection that is not shared with other users on the network.
The most commonly implemented wired protocol is the Ethernet protocol. Ethernet uses a suite of protocols that allow network devices to communicate over a wired LAN connection. An Ethernet LAN can connect devices using many different types of wiring media.
Directly connected devices use an Ethernet patch cable, usually unshielded twisted pair. These cables can be purchased with the RJ-45 connectors already installed, and they come in various lengths. Recently constructed homes may have Ethernet jacks already wired in the walls of the home. For those homes that do not have UTP wiring, there are other technologies, such as powerline, that can distribute wired connectivity throughout the premises.
Click each wired technology for more information.
Catagory 5e Cable
Category 5e is the most common wiring used in a LAN. The cable is made up of 4 pairs of wires that are twisted to reduce electrical interference.
Coaxial Cable
Coaxial cable has an inner wire surrounded by a tubular insulating layer, that is then surrounded by a tubular conducting shield. Most coax cables also have an external insulating sheath or jacket.
Fiber-Optic Cable
Fiber-optic cables can be either glass or plastic with a diameter about the same as a human hair and it can carry digital information at very high speeds over long distances. Fiber-optic cables have a very high bandwidth, which enables them to carry very large amounts of data.
Check your understanding of network technologies in the home by choosing the correct answer to the following questions.
A number of standards have been developed to ensure that wireless devices can communicate. They specify the RF spectrum used, data rates, how the information is transmitted, and more. The main organization responsible for the creation of wireless technical standards is the Institute of Electrical and Electronics Engineers (IEEE).
The IEEE 802.11 standard governs the WLAN environment. There are amendments to the IEEE 802.11 standard that describe characteristics for different standards of wireless communications. Wireless standards for LANs use the 2.4 GHz and 5 GHz frequency bands. Collectively these technologies are referred to as Wi-Fi.
Another organization, known as the Wi-Fi Alliance, is responsible for testing wireless LAN devices from different manufacturers. The Wi-Fi logo on a device means that this equipment meets standards and should operate with other devices that use the same standard.
Wireless standards are constantly improving the connectivity and speed of Wi-Fi networks. It is important to be aware of new standards as they are introduced because manufacturers of wireless devices will implement these standards quickly in their new products.
Do you have a wireless network in your home? Do you know what standards are supported by your wireless router?
The Packet Tracer Basic Wireless Settings interface is shown in the figure. Wireless routers using the 802.11 standards have multiple settings that have to be configured. These settings include the following:
Network Mode
Determines the type of technology that must be supported. For example,802.11b,802.11g,802.11n or Mixed Mode.
Network Name(SSID)
Used to identify the WLAN. All devices that wish to participate in the WLAN must have the same SSID.
Standard Channel
Specifies the channel over which communication will occur. By default, this is set to Auto to allow the access point (AP) to determine the optimum channel to use.
SSID Broadcast
Determines if the SSID will be broadcast to all devices within range. By default, set to Enabled.
Note: SSID stands for Service Set Identifier.
Network Mode
The 802.11 protocol can provide increased throughput based on the wireless network environment. If all wireless devices connect with the same 802.11 standard, maximum speeds can be obtained for that standard. If the access point is configured to accept only one 802.11 standard, devices that do not use that standard cannot connect to the access point.
A mixed mode wireless network environment can include devices that use any of the existing Wi-Fi standards. This environment provides easy access for older devices that need a wireless connection but do not support the latest standards.
When building a wireless network, it is important that the wireless components connect to the appropriate WLAN. This is done using the SSID.
The SSID is a case-sensitive, alphanumeric string that contains up to 32 characters. It is sent in the header of all frames transmitted over the WLAN. The SSID is used to tell wireless devices, called wireless stations (STAs), which WLAN they belong to and with which other devices they can communicate.
We use the SSID to identify a specific wireless network. It is essentially the name of the network. Wireless routers usually broadcast their configured SSIDs by default. The SSID broadcast allows other devices and wireless clients to automatically discover the name of the wireless network. When the SSID broadcast is disabled, you must manually enter the SSID on wireless devices.
Disabling SSID broadcasting can make it more difficult for legitimate clients to find the wireless network. However, simply turning off the SSID broadcast is not sufficient to prevent unauthorized clients from connecting to the wireless network. All wireless networks should use the strongest available encryption to restrict unauthorized access.
Check your understanding of wireless standards by choosing the correct answer to the following questions.
Many wireless routers designed for home use have an automatic setup utility that can be used to configure the basic settings on the router. These utilities usually require a PC or laptop to be connected to a wired port on the router. If no device is available that has a wired connection, it may be necessary to configure the wireless client software on the laptop or tablet first.
To connect to the router using a wired connection, plug an Ethernet patch cable into the network port on the computer. Plug the other end into a LAN port on the router. Do not plug the cable into the port or interface that is labeled “Internet”. The internet port will connect to the DSL or cable modem. Some home routers may have a built-in modem for internet connections. If this is the case, verify that the type of connection is correct for your internet service. A cable modem connection will have a coaxial terminal to accept a BNC-type connector. A DSL connection will have a port for a telephone-type cable, usually an RJ-11 connector.
After confirming that the computer is connected to the network router and the link lights on the NIC indicate a working connection, the computer needs an IP address. Most network routers are set up so that the computer receives an IP address automatically from a local DHCP server automatically configured on the wireless router. If the computer does not have an IP address, check the router documentation and configure the PC or tablet with a unique IP address, subnet mask, default gateway, and DNS information.
Before entering the configuration utility, or manually configuring the router through a web browser, you should consider how your network will be used. You do not want to configure the router and have that configuration limit what you are able to do on the network, nor do you want to leave your network unprotected.
What should my network be called ?
If SSID broadcasting is on, the SSID name will be seen by all wireless clients within your signal range. Many times the SSID gives away too much information about the network to unknown client devices. It is not a good practice to include the device model or brand name as part of the SSID. Wireless devices have default settings that are easy to find on the internet, as well as known security weaknesses.
What types of devices will attach to my network ?
Wireless devices contain radio transmitter/receivers that function within a specific frequency range. If a device only has the necessary radio for 802.11 b/g, it will not connect if the wireless router or access point is configured to only accept 802.11n or 802.11ac standards. If all devices support the same standard, the network will work at its optimum speed. If you have devices that do not support the n or ac standards, then you will have to enable legacy mode. A legacy mode wireless network environment varies between router models but can include a combination of 802.11a, 802.11b, 802.11g, 802.11n, and 802.11ac. This environment provides easy access for legacy devices that need a wireless connection.
How do I add new devices ?
The decision regarding who can access your home network should be determined by how you plan to use the network. On some wireless routers, it is possible to set up guest access. This is a special SSID coverage area that allows open access but restricts that access to using the internet only.
The figure shows a wireless setup screen.
Note: Some wireless routers may label legacy mode as mixed mode.
Press the Play button to watch the video.
In this Packet Tracer activity, you will complete the following objectives.
Most home networks consist of at least two separate networks. The public network coming in from the service provider. The router is connected to the internet. Most likely, the home router is equipped with both wired and wireless capabilities. A home network is a small LAN with devices that usually connect to an integrated router and to each other in order to exchange information.
Wireless technology is fairly easy and inexpensive to install. Advantages of wireless LAN technology include mobility, scalability, flexibility, cost savings, reduced installation time, and reliability in harsh environments.
In addition to an integrated router, there are many different types of devices that might be connecting to a home network, Examples include desktop computers, gaming systems, smart tv systems, printers, scanners, security cameras, and climate control devices.
Small business and home routers typically have two primary types of ports: ethernet ports and internet ports. In addition to the wired ports, many home routers include a radio antenna and a built-in wireless access point.
Network Technologies in the Home
Wireless technologies use electromagnetic waves to carry information between devices. The electromagnetic spectrum includes such things as radio and television broadcast bands, visible light, x-rays, and gamma-rays. Some types of electromagnetic waves are not suitable for carrying data. Other parts of the spectrum are regulated by governments and licensed to various organizations for specific applications.
Certain unlicensed sections of the spectrum are incorporated into consumer products, including the Wi-Fi routers found in most homes. The wireless technologies most frequently used in home networks are in the unlicensed 2.4 GHz and 5 GHz frequency ranges. Bluetooth is a technology that makes use of the 2.4 GHz band. Other technologies that use the 2.4 GHz and 5 GHz bands are the modern wireless LAN technologies that conform to the various IEEE 802.11 standards. Unlike Bluetooth technology, 802.11 devices transmit at a much higher power level giving them a great range and improved throughput.
Although many home network devices support wireless communications, there are still a few applications where devices benefit from a wired switch connection. The most commonly implemented wired protocol is the Ethernet protocol. Directly connected devices use an Ethernet patch cable, usually unshielded twisted pair. Category 5e is the most common wiring used in a LAN. The cable is made up of 4 pairs of wires that are twisted to reduce electrical interference. For those homes that do not have UTP wiring, there are other technologies, such as powerline, that can distribute wired connectivity throughout the premises.
Wireless standards
The IEEE 802.11 standard governs the WLAN environment. Wireless standards for LANs use the 2.4 GHz and 5 GHz frequency bands. Collectively these technologies are referred to as Wi-Fi. The Wi-Fi Alliance is responsible for testing wireless LAN devices from different manufacturers.
Wireless routers using the 802.11 standards have multiple settings that have to be configured. These settings include the following:
The 802.11 protocol can provide increased throughput based on the wireless network environment. If all wireless devices connect with the same 802.11 standard, maximum speeds can be obtained for that standard. If the access point is configured to accept only one 802.11 standard, devices that do not use that standard cannot connect to the access point. A mixed mode wireless network environment can include devices that use any of the existing Wi-Fi standards.
When building a wireless network, it is important that the wireless components connect to the appropriate WLAN. This is done using the SSID. The SSID is used to tell wireless devices, called STAs, which WLAN they belong to and with which other devices they can communicate. The SSID broadcast allows other devices and wireless clients to automatically discover the name of the wireless network. When the SSID broadcast is disabled, you must manually enter the SSID on wireless devices.
Set up a Home Router
Many wireless routers designed for home use have an automatic setup utility that can be used to configure the basic settings on the router. To connect to the router using a wired connection, plug an Ethernet patch cable into the network port on the computer. Plug the other end into a LAN port on the router.
After the computer is connected to the network router and the link lights on the NIC indicate a working connection, the computer needs an IP address. Most network routers are set up so that the computer receives an IP address automatically from a local DHCP server automatically configured on the wireless router.
Before entering the configuration utility, or manually configuring the router through a web browser, you should consider how your network will be used. Consider what you will call your network and what devices should connect to your network. It is not a good practice to include the device model or brand name as part of the SSID since internet searches can expose security weaknesses.
The decision regarding who can access your home network should be determined by how you plan to use the network. Many routers support MAC address filtering. This enables you to specifically identify who is allowed on the wireless network. This makes the wireless network more secure, but it also less flexible when connecting new devices. On some wireless routers, it is possible to set up guest access. This is a special SSID coverage area that allows open access but restricts that access to using the internet only.
I had such a good time taking this module at the beach, that I think I’m going to set up a wireless network at home. That way, I can keep up with this course anywhere in my home. Building your home network to be a wireless network just makes sense. I can work in the west side of my web and catch the sun setting, then move back to the east side in the morning. It’s so much nicer than being stuck at my desk all day! Have you set up your own home network? If not, could you do it if you had to?
Welcome to the Build a Small Network Checkpoint Exam.
There are 20 questions in total.
Items on this exam support the following Cybersecurity skills:
The next day, Kishori has a new patient, Srinivas, who has just been admitted to a room. He is from Narayanpet and speaks Telugu. Kishori speaks Marathi. These two Indian languages are very different. Kishori and Srinivas do not speak each other’s native language. However, they do both speak English. Therefore, they decide to communicate using English.
Before beginning to communicate with each other, we establish rules or agreements to govern the conversation. Just like Kishori and Srinivas, we decide what method of communication we should use, and what language we should use. We may also need to confirm that our messages are received. For example, Kishori may have Srinivas sign a document verifying that he has understood Kishori’s care instructions.
Networks also need rules, or protocols, to ensure successful communication. This module will cover the communication principles for networks. Let’s get started!
Module Title: Communication Principles
Module Objective: Explain the importance of standards and protocols in network communications.
Topic Title | Topic Objective |
---|---|
Communication Protocols | Describe network communication protocols. |
Communication Standards | Describe network communication standards. |
Network Communication Models | Compare the OSI and TCP/IP models. |
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:
Click below for an example of determining the method, language, and confirmation strategies.
Method
Language
Confirmation
These rules, or protocols, must be followed in order for the message to be successfully delivered and understood. Among the protocols that govern successful human communication are these:
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.
Just like humans, computers use rules, or protocols, in order to communicate. Protocols are required for computers to properly communicate across the network. In both a wired and wireless environment, a local network is defined as an area where all hosts must “speak the same language”, which, in computer terms means they must “share a common protocol”.
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.
Networking protocols define many aspects of communication over the local network. As shown in the table, these include message format, message size, timing, encoding, encapsulation, and message patterns.
Protocol Characteristic | Description |
---|---|
Message format | When a message is sent, it must use a specific format or structure. Message formats depend on the type of message and the channel that is used to deliver the message. |
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. 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. |
Timing | Many network communication functions are dependent on 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. The destination host receives and decodes the signals in order to interpret the message. |
Encapsulation | 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. Encapsulation 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. |
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. |
Check your understanding of communication protocols by choosing the correct answer to the following questions.
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.
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, as shown in the figure. 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 are shown in the figure.
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, as shown in the figure. 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 are shown in the figure.
Check your understanding of communication standards by choosing the correct answer to the following questions.
Other standards organizations that support the internet are shown in the figure.
Press the Play button to watch the video.
Press the Play button to watch the video.
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:
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 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, as shown in the table. Because of this, the internet model is commonly referred to as the TCP/IP 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.
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 OSI model.
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. |
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.
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.
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:
Protocols are required for computers to properly communicate across the network. These include message format, message size, timing, encoding, encapsulation, and message patterns.
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.
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:
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.
OSI Model Layer Description
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