Ccna module 1: Networking Today Introduction to Networks (itn)

Introduction to Networks - Module 1: Understanding Networks

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  Networks affect our lives by enabling communication and interconnectivity, becoming increasingly important during the COVID-19 pandemic
  
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  The future generations will be more connected than the current ones, and networks play a crucial role in breaking down global boundaries
  
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  Network systems include various components, such as hosts, end devices, and servers
  
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  Servers, like email servers, web servers, and file servers, are computers that provide information to end devices and are typically accessed by multiple clients
  
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  Networks can be represented on paper and electronic documents using network representations and topologies
  
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  Common types of networks include Local Area Networks (LANs), Wide Area Networks (WANs), and Metropolitan Area Networks (MANs)
  
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  Internet connections, such as landlines and satellite connections, interconnect networks globally
  
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  Reliable networks have four basic requirements: availability, reliability, resiliency, and security
  
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  Network trends include Bring Your Own Device (BYOD), online collaboration, video, cloud computing, and network security
  
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  Understanding network security threats and solutions is essential for IT professionals in the networking field
  
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  Employment opportunities in the networking field include network engineering and network analyst positions
  

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  Hosts, also known as end devices, are computers or other devices connected to a network
  
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  Servers are computers that provide information to end devices and are typically accessed by multiple clients
  
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  Network components are defined based on the infrastructure of networks and how they have been put together to create global communication networks
  

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  Networks can be represented on paper and electronic documents using network representations and topologies
  
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  Topologies describe the arrangement of a network, including its nodes and connecting lines
  

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  Common types of networks include Local Area Networks (LANs), Wide Area Networks (WANs), and Metropolitan Area Networks (MANs)
  
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  Networks can be interconnected globally using internet connections, such as landlines and satellite connections
  

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  Reliable networks have four basic requirements: availability, reliability, resiliency, and security
  
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  Availability refers to the percentage of time that a network is available for use
  
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  Reliability refers to the network's ability to transmit data accurately
  
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  Resiliency refers to the network's ability to recover from failures
  
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  Security refers to the network's ability to protect data from unauthorized access and attacks
  

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  Network trends include Bring Your Own Device (BYOD), online collaboration, video, cloud computing, and network security
  
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  BYOD refers to the practice of allowing employees to use their personal devices for work purposes
  
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  Online collaboration and video tools enable remote work and virtual meetings
  
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  Cloud computing allows for the storage and access of data and applications over the internet
  
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  Network security is becoming increasingly important as networks become more complex and interconnected
  

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  Understanding network security threats and solutions is essential for IT professionals in the networking field
  
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  Common network security threats include malware, phishing, and denial-of-service (DoS) attacks
  
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  Network security solutions include firewalls, intrusion detection systems (IDS), and encryption
  

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  Employment opportunities in the networking field include network engineering and network analyst positions
  
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  IT professionals in the networking field should have a strong understanding of network components, representations, topologies, and security
  

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  Client computers send requests to servers to retrieve information (e.g. web pages, emails)
  
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  Servers run email, web, and file server software
  
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  Clients are the end devices that request services from servers
  
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  Servers contain dedicated services that provide those services (e.g. email, web, file)
  

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  Peer-to-peer networks have no central authority
  
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  No privilege over anyone, all peers are equal
  
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  Most corporate networks do not use peer-to-peer networks due to security and control issues
  
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  Peer-to-peer networks must have the exact same operating system to communicate
  
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  Peer-to-peer networks are typically not scalable and are only used for simple tasks such as sending data directly to a printer
  

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  End devices are where messages originate from or are received
  
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  Examples of end devices include computers, laptops, and mobile devices
  
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  End devices are used to access data on a network
  

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  Intermediary network devices interconnect end devices
  
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  Examples of intermediary network devices include switches, wireless access points, routers, and firewalls
  
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  Intermediary network devices are used for management of data as it flows through the network
  

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  In the future, we will go into depth on how the client-server model works and how intermediary network devices manage data flow through the network.
  

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  Intermediary devices manage the data as it flows through the network
  
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  They ensure that the end user at one end gets what they want and the end user at the other end receives exactly what was sent
  

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  Network media allow communication across networks through a medium that allows messages to travel between source and destination
  
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  In the past, most network media was made out of metal wires. Today, modern high-speed network communication systems include fiber optics or glass or plastic fibers and wireless transmission
  
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  Fiber optics are faster, more reliable, and more secure than metal wires. Wireless transmission is easy to set up and flexible, but it is not as secure and more prone to errors
  

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  Network diagrams, also called topology diagrams, use symbols to represent devices within the network
  
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  The network interface card (NIC) is a physical connection port that allows you to connect to the network
  
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  The physical port and interface are often used interchangeably and are typically associated with the NIC
  
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  Network topology diagrams can be put into two different categories: physical topology and logical topology
  

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  Physical topology refers to the physical layout of a network, including the devices, cables, and connections
  
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  Logical topology refers to the way data flows through a network, including the paths and protocols used for communication
  

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  Bus topology: all devices are connected to a single cable
  
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  Ring topology: all devices are connected to each other in a circular fashion
  
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  Star topology: all devices are connected to a central hub or switch
  
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  Tree topology: a combination of bus, ring, and star topologies
  
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  Mesh topology: each device is connected to every other device in the network
  

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  Understanding network topologies can help you design, implement, and troubleshoot a network
  
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  Different topologies have different advantages and disadvantages, and choosing the right one depends on the specific needs of the network
  

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  There are two types of network topologies: physical and logical
  
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  Physical topology diagrams illustrate the physical location of intermediary devices and cables
  
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  Logical topology diagrams illustrate devices, ports, and addressing schemes of the network
  
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  Physical topology is based on the actual physical location of the device
  
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  Logical topology is based on how the router or a particular network device separates other devices, regardless of where the device is located
  

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  Small home networks: connect a few computers to each other and the internet
  
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  Small office/home office (SOHO) networks: enable computers within a home or remote office to connect to a corporate network
  
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  Medium to large networks: seen typically in private companies, small companies, and government agencies with a specific location
  
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  Worldwide networks: large interconnected global networks such as shipping companies or credit card companies and the internet
  

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  A router is used to logically separate different sections of a network, regardless of where the devices are physically located
  
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  Small home networks connect a few devices directly to the internet, while SOHO networks enable computers within a home or remote office to connect to a corporate network
  
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  Medium to large networks and worldwide networks are typically found in specific locations such as private companies, small companies, government agencies, and global corporations
  

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  How routers separate network topologies
  
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  Common types of network devices
  
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  Network protocols and standards
  

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  Small Home Networks: Connects devices within a home
  
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  Small Office/Home Office (SOHO) Networks: Connects multiple devices within a small office or home office
  
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  Medium to Large Networks: Connects hundreds of thousands of interconnected computers in multiple locations
  
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  Worldwide Networks: Connects hundreds of millions of computers worldwide, including the internet
  

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  LAN: Network infrastructure that spans a small geographical area, administered typically by a single organization or individual, and provides high-speed bandwidth to internal devices
  
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  WAN: Network infrastructure that spans a wide geographical area, administered typically by one or more service providers, and provides slower speeds links between the lands
  

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  LAN interconnects a limited number of devices in a limited area, while WAN interconnects multiple LANs over a wide geographical area
  
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  LAN provides high-speed bandwidth, while WAN provides slower speeds
  
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  LAN is typically administered by a single organization or individual, while WAN is typically administered by one or more service providers
  

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  Worldwide collection of interconnected LANs and WANs
  

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  The speed of WAN is getting better with the advancement of fiber optics, but it is typically slower than LAN.
  

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  Data centers are connected to each other using vans
  
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  Vans may use copper wires, fiber optic cables, and even wireless transmission to communicate with each other
  

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  Wireless transmission is used to communicate between different sites and communities
  
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  Satellite communication systems that connect multiple different countries can be considered as a type of wireless network
  

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  The internet is not owned by an individual or group
  
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  Groups such as IETF, ICAN, and IAB are involved in developing and maintaining the structures on the internet
  
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  IETF is responsible for standardizing most of the network infrastructure
  
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  ICAN is responsible for things like the IP address signing and the global world wide web web addresses
  

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  The common types of networks include the intranet, extranet, and internet
  
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  Intranet is a private collection of lands and vans internal to the organization and is meant to be accessible only to the organization's members or others within the authorization
  
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  Extranet can be used by an organization to provide secure access to their network for individuals who work for a different organization
  

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  Intranet and extranet are key terms that you should know for your CCNA and CCNP exams
  

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  Different types of ways to connect to the internet
  
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  Home and small office internet connections: cable, DSL, cellular, satellite, dial-up
  
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  Cable connections include fiber net networks and other types of specialized cables that provide high bandwidth always-on internet
  
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  DSL includes high bandwidth always-on internet connection that runs over a telephone line
  
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  Cellular networks allow internet connections to your cell phones, useful especially if you are going somewhere outside and there is coverage available
  
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  Satellite networks provide internet connections to rural areas through a direct satellite connection between the satellite itself and your home or small office
  
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  Dial-up connections are inexpensive, low bandwidth, but not very reliable and used in some parts of the world
  
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  In Canada, most internet connections are either cable or DSL, and also cellular in rural parts of Europe and Canada, satellite communication is used
  
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  Business internet connections include dedicated lease lines (T1, T2) that provide very high bandwidth and high availability
  
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  Ethernet WAN extends LAN access technology into the WAN, allowing communication between two different locations
  
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  These definitions may slightly change as technology advances
  

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  Cable connections: high bandwidth, always-on internet offered by television service providers
  
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  DSL: high bandwidth, always-on internet connection that runs over a telephone line
  
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  Cellular networks: internet connections to your cell phones, useful especially if you are going somewhere outside and there is coverage available
  
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  Satellite networks: internet connections to rural areas through a direct satellite connection between the satellite itself and your home or small office
  
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  Dial-up: inexpensive, low bandwidth, but not very reliable and used in some parts of the world
  

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  Dedicated lease lines (T1, T2): more expensive but provide very high bandwidth and high availability
  
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  Ethernet WAN: extends LAN access technology into the WAN, allowing communication between two different locations
  

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  The technology is moving at a fast pace, and the definitions of these connections may change over time.
  
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  In Canada, most internet connections are either cable or DSL, and also cellular in rural parts of Europe and Canada, satellite communication is used.
  

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  In some parts of the world, dial-up internet connections are still being used, and it is important to know how they work and how they are utilized by different users.
  
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  In rural areas, satellite communication is being used, and companies like Starlink provide end-users with the option to buy satellite systems that can be hooked up to their roof or something to get the internet.
  

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  Leased lines, Digital Subscriber Lines (DSL) such as Business DSL, SDSL (Symmetric Digital Subscriber Lines), and Satellite connections
  
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  These connections provide higher bandwidth, dedicated connections, and managed services such as dedicated lines for voice, web access, or specific software systems
  

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  Converged networks carry multiple services on a single link
  
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  They use the same set of rules and standards, and technologies such as VLAN, ACL (Access Control List), and QoS (Quality of Service) to ensure proper delivery of data
  

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  Used in this course for CCNA and CCNP studies
  
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  Allows for the creation of network representations and has modules for labs to learn network systems and engineering
  

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  Based on multiple concepts coming together to build a better system
  
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  Will be discussed in the next section of this module
  

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  Refers to the technologies that support the infrastructure for data movement across the network
  
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  Can be made reliable by utilizing four basic characteristics: fault tolerance, scalability, quality of service (QoS), and security
  

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  A fault tolerance network limits the impact of a failure by limiting the number of affected devices
  
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  Provides redundancy by implementing a packet switch network, allowing for multiple paths for data to take
  
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  Increases fault tolerance by splitting traffic into packets and sending them over different paths to the same destination
  

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  A scalable network can expand quickly and easily to support new users and applications without impacting the performance of existing users
  
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  Requires the use of accepted standards and protocols to ensure easy and quick expansion
  
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  Allows for the addition of new devices or intermediate devices without impacting the performance of existing users
  

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  QoS ensures that the network can prioritize certain types of data and allocate resources accordingly
  
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  This is important for real-time applications such as video conferencing or VoIP, which require a certain level of performance to function properly
  

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  Security measures are in place to protect the network and its data from unauthorized access or malicious attacks
  
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  This can include measures such as encryption, firewalls, and access controls
  

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  QoS is very important for services that cannot take latency or cannot tolerate latency, such as voice and live video transmissions
  
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  If packets are lost in these transmissions, it can cause confusion and make the transmission completely useless
  
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  QoS is used to ensure the reliable delivery of content for all users by managing the flow of data and prioritizing certain traffic
  

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  High demand for bandwidth than the available bandwidth in a particular system can cause constant breaks and buffering in live video transmissions
  
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  If QoS is not implemented in a home router or modem, bandwidth will be split randomly and can cause delays in voice packets
  

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  There are two main types of network security: network infrastructure security and information security
  
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  Network infrastructure security includes physical security of network devices and preventing unauthorized access to those devices
  
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  Information security is the protection of data transmitted over the network through encryption and authentication
  

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  The three goals of network security are confidentiality, integrity, and availability
  

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  QoS is one of the primary mechanisms used to ensure the reliable delivery of content for all users, which is important for network security
  
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  With QoS policy in place, a router can prioritize certain traffic, such as voice or video, over other traffic, such as file downloads, to ensure the reliable delivery of those packets
  

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  Data integrity refers to the accuracy, consistency, and completeness of data during its entire lifecycle.
  
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  It ensures that the data has not been tampered or altered during the transmission.
  

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  It assures that the data has not been tampered or altered during the transmission.
  
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  The data that needed to be accessed can be accessed in a timely and reliable manner by all the authorized users.
  

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  Confidentiality, integrity, and availability (CIA) are the three key principles of information security.
  
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  Data availability is important for organizations and consumers in modern day, especially with the rise of remote work and online collaboration.
  

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  Administrators can protect the software and hardware using encryption and logging authentication systems.
  
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  Regular backups and disaster recovery plans can also help ensure data integrity.
  

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  Bring Your Own Device (BYOD) allows users to use their own devices, giving them opportunities and greater flexibility.
  
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  Online collaboration allows users to collaborate and work with others over the network on joint projects.
  
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  Cloud computing allows organizations and consumers to buy cloud services instead of having their own physical data centers.
  

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  BYOD allows users to have the freedom to use their personal tools to access information and communicate.
  
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  Any device with any ownership can be used by anyone anywhere else on your network as long as they have the authorizations and authentications to access resources within your network.
  

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  Online collaborations allow users to collaborate and work with others over the network on joint projects.
  
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  This is how the internet first started when in the United States a bunch of universities got together to share resources and information.
  

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  The Internet began as a network that connected research institutions for scientific collaboration
  
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  Modern collaboration tools include Cisco Webex, Microsoft Teams, and Office 365
  
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  These tools allow for real-time collaboration on documents and instant communication
  

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  Collaboration is a high priority for businesses and the educational research sector
  
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  Cisco Webex Teams is a multi-functional tool used by large companies, organizations, and institutions
  

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  Video communication is becoming more important as more people work remotely
  
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  Tools like Cisco Telepresence allow for the sharing of physical materials and data during video calls
  

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  Cloud computing allows for the storage and backup of data and files on servers over the Internet
  
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  It allows for access to applications and data from any device, anywhere in the world
  
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  Cloud computing is made possible by large data centers, and there are different types including public and private clouds
  

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  Cloud computing allows smaller companies to outsource their storage and physical services
  
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  It increases reliability and allows for access to data and services from anywhere
  

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  A private cloud is a type of cloud system that is used by a single organization and is not shared with any other entities
  
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  A hybrid cloud is made up of two or more cloud types, such as a combination of custom and public clouds, that are interconnected using a semi-architecture
  
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  An example of a hybrid cloud is the University of Calgary's Unicity Cal initiative, where professors and researchers interact on a custom cloud while the public can access a public cloud to collaborate
  

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  Custom clouds are built to meet the needs of specific industries, such as healthcare, media, or oil and gas
  
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  They can be either private or public, and are useful for accessing data from remote locations with high reliability
  
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  An example of a custom public cloud is a rural town in Japan that created a cloud system for public schools to access information
  

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  Smart homes technology is a growing trend that allows everyday appliances to be integrated and interconnected with other devices
  
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  Examples of smart home technology include automation tools that allow users to control lights, check if garage doors are open, and even cook meals based on schedules
  

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  Power line networking is a technology that has been around for a long time and allows devices to connect to a LAN using electrical cables and a power line standard adapter
  
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  It is useful for connecting devices that are far away from a network hub or router, or in places where running data cables is not feasible
  

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  Wireless broadband is another option for accessing the internet, in addition to DSL and cable
  

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  Wireless Internet Service Providers (WISPs) commonly found in rural environments
  
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  High-powered communication broadband towers send signals over a wide area
  
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  Wireless Broadband for home and small businesses uses cellular technology
  
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  Antenna installed outside of the house provides wireless or wired connectivity
  

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  Important for all networks, regardless of size
  
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  Security measures must balance data protection and quality of service
  
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  Involves many protocols, technologies, devices, tools, and techniques
  

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  External threats: viruses, worms, Trojan horses, spyware, adware, zero-day attacks, threat actor attacks, denial of service attacks, data interception and theft, identity theft
  
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  Internal threats: lost or stolen devices, accidental misuse by an employee, employees with intention of harming the organization
  

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  Implemented in multiple layers using more than one security solution
  
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  Network security components for home or small office networks: anti-viruses, anti-spyware software, firewall filtering in intermediate devices or separate firewall devices
  
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  Large networks have additional security requirements such as dedicated firewall systems, intrusion prevention systems, and virtual private networks (VPNs)
  

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  Begins with a clear understanding of network security principles and best practices
  
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  Continuous learning and staying up-to-date on new threats and security solutions is essential
  

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  Understanding the underlying infrastructure of switching and routing is crucial in networking
  
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  CCNA and CCNP certifications demonstrate knowledge of foundational technologies and ensure relevance with next generation technologies
  
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  New DevNet certifications validate software development skills for networking jobs
  
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  Employment opportunities can be found on the NetAcad website, local websites, and local companies
  
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  Cisco Network Academy students and alumni can make connections on the Cisco website
  

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  All computers connected to a network and participating in network communication are classified as hosts
  
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  Diagrams of networks use symbols to represent devices and connections
  
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  Logical diagrams provide an easy way to understand how devices connect in a large network
  
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  Local Area Networks (LAN) and Wide Area Networks (WAN) are two types of network infrastructures
  
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  Network architecture refers to the topologies, services, and protocols that move data across the network
  

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  Fault tolerance, scalability, QoS (Quality of Service), and security are the four basic characteristics of a network architecture
  

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  Bringing Your Own Device (BYOD), online collaboration, video communications, and cloud computing are recent networking trends
  

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  Larger networks and corporate networks use antiviruses, anti-spyware, and firewall filtering
  
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  Other security requirements include dedicated firewall systems, access control lists (ACLs), intrusion prevention systems (IPS), and virtual private networks (VPN)
  

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  CCNA certification demonstrates knowledge of foundational technologies
  
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  CCNP certification ensures relevance with skills needed for adaption of next generation technologies
  
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  DevNet certifications validate software development skills for networking jobs
  

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  Employment opportunities can be found on the NetAcad website, local websites, and local companies
  
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  Cisco Network Academy students and alumni can make connections on the Cisco website
  
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  Cisco Talent Bridge matching engine can be used to find opportunities
  

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  The badges displayed represent the completion of a module on network systems
  
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  They show that the learner has obtained knowledge in the basics of network systems and practical applications
  
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  The knowledge gained from this module can be applied to daily life
  
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  CCNA and CCNP certifications can be obtained through registered organizations that administer the courses and exams
  

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  Additional supporting videos will be posted in the future
  
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  New modules in this series will also be published in the near future
  
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  Listening to different people talk about the same slide set allows students to gain more in-depth knowledge of network systems by understanding the concepts in different ways
  

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  The slide set used in this explanation is provided by Cisco and is copyrighted by the company
  
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  The information is free to use for educational purposes
  

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  The speaker encourages the audience to subscribe, give a thumbs up, and stay tuned for the next module which will be published in a few days
  

CCNA Module 3: Protocols and Models: Introduction to Networking

Introduction to Protocols and Models in Networking

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  Learn about protocols and models that enable devices to access local and remote network resources
  
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  Understand the importance of rules and protocols in network communication
  
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  Learn about the role of standard organizations in enforcing protocols
  
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  Understand the concept of data encapsulation and data access
  
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  Additional slides on the OSI model will be included for a better understanding
  

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  A link to a Cisco video explaining the protocols that devices use to communicate will be provided
  
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  The video covers the basics of network communication
  

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  Networks can vary in size and complexity
  
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  Three elements of network communication: source, destination, and channel
  
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  Communications are governed by protocols, which are rules that dictate how communication occurs
  

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  A message needs to be sent
  
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  The message must be formatted according to the rules of the protocol
  
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  The message must be sent over a specific channel or medium
  
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  The message must be received and interpreted by the destination
  

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  TCP/IP model
  
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  ISO model
  
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  Standard organizations such as IEEE and IETF
  

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  Data is wrapped in a header that contains information about the data
  
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  The header is used to guide the data through the network
  
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  Data access is the ability for a device to access resources on a network
  
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  Localhost is used to access resources on the same device
  

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  Additional information about the Cisco slice set will be provided
  
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  The slice set is a set of guidelines for network communication
  

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  The OSI model is a framework for understanding how data is transmitted over a network
  
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  It consists of seven layers: physical, data link, network, transport, session, presentation, and application
  
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  Each layer has a specific function in the transmission process
  

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  Understanding protocols and models is essential for network communication
  
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  Standard organizations play a crucial role in enforcing protocols
  
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  Data encapsulation and data access are important concepts in network communication
  
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  The OSI model provides a framework for understanding how data is transmitted over a network
  

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  Communication involves a message being sent from a source, through a transmitter, transmitter medium, and receiver, and then reaching a destination
  
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  Established rules or agreements, such as a common language and grammar, must be used to govern the conversation
  
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  The first message in this example is difficult to read due to poor formatting, while the second message is properly formatted and easier to understand
  

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  Protocols must account for the following requirements: an identified sender and receiver, a common language and grammar, proper formatting, speed and timing of delivery, and confirmation or acknowledgement of the message
  
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  Network protocol requirements include common computer protocols such as message encoding, message formatting and encapsulation, message size, message timing, and message delivery options
  

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  Encoding is the process of converting information into another acceptable form of transmission, decoding reverses this process
  
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  The encoding process takes the message from the source and encodes it so that it can be transmitted through different layers and received by the destination
  
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  Message formatting and encapsulation: when a message is sent, it must use specific formats or structures depending on the type of message and the channel it is used to deliver the message
  

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  Email: specific email message format such as POP or SMTP
  
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  Physical message: paper and pencil or paper and pen
  
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  Website or social media: HTTP or HTTPS protocol
  

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  The size of the message is important to ensure that it can be transmitted and received without issues
  
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  The message size should not exceed the maximum limit set by the network protocol
  

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  The timing of the message is important to ensure that it is received in a timely manner
  
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  The message should be sent and received within the agreed-upon time frame to avoid delays or loss of the message
  

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  There are different message delivery options such as best effort, reliable, and guaranteed delivery
  
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  Best effort delivery: the message is sent, but there is no guarantee that it will be received
  
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  Reliable delivery: the message is sent and an acknowledgement is received when it is received
  
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  Guaranteed delivery: the message is sent and an acknowledgement is received, and if the message is not received, it is re-sent
  

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  Data packets have encapsulated the AI's information for transmission through a network
  
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  They contain various pieces of information, including version, traffic class, flow label, destination IP, source IP, payload length, next header, and hop limit
  
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  When an email or message is sent, it is converted to bits and encoded into patterns of light, sound, or electrical impulses for transmission
  
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  At the destination, the signal is decoded to interpret the message
  

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  The message size includes the flow control, response timeout, and access method
  
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  The flow control manages the rate of data transmission and defines how much information can be sent and the speed at which it can be delivered
  
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  The response time manages how long a device waits when it does not hear a reply back from the destination
  
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  The access method determines when someone can send a message
  

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  The message timing includes the flow control, response timeout, and access method
  
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  The flow control manages the rate of data transmission and defines how much information can be sent and the speed at which it can be delivered
  
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  The response time manages how long a device waits when it does not hear a reply back from the destination
  
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  The access method determines when someone can send a message
  

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  The access method determines when someone can send a message
  
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  There may be various rules and protocols in place to regulate when and how a device can send a message
  

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  Error messages, such as response timeout, may be displayed when there are too many requests going into a server or if there is a problem with the transmission of data
  

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  Data is transmitted through a network by converting the message to bits and encoding it into patterns of light, sound, or electrical impulses
  
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  The encoded message is then sent through the network to the destination, where it is decoded and interpreted
  

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  The source and destination IP addresses are included in the data packet to ensure that the message is sent to the correct location
  

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  The payload length indicates the length of the actual data being transmitted
  

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  The next header indicates the type of data that is being transmitted
  

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  The hop limit indicates the maximum number of hops (or routers) that the message can pass through before it is discarded
  

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  The traffic class indicates the priority of the message and can be used to determine the order in which messages are transmitted
  

• 
  The flow label is used to identify a specific flow of messages and can be used to manage the transmission of those messages
  

• 
  Light is electromagnetic radiation that is visible to the human eye
  
• 
  It has a wavelength of 400-700 nanometers and a frequency of approximately 430-770 terahertz
  
• 
  Light waves are electromagnetic waves that travel through the vacuum of space
  
• 
  They are produced when an object vibrates, and they travel at the speed of light
  

• 
  Light has both wave-like and particle-like properties
  
• 
  It exhibits wave-like properties when it interferes with other light waves
  
• 
  It exhibits particle-like properties when it is emitted or absorbed by matter
  

• 
  The speed of light in a vacuum is 186,282 miles per second (299,792 kilometers per second)
  
• 
  The speed of light can be measured with a laser beam or a light-emitting diode
  

• 
  There are three sections in message timing: flow control, response timer, and access method
  
• 
  The message delivery options include unicast, multicast, and broadcast
  
• 
  Flow control, response timer, and access method work together to control message timing and access control in networks
  

• 
  Unicast is a one-to-one communication
  
• 
  Multicast is a one-to-many communication
  
• 
  Broadcast is a one-to-all communication
  

• 
  A protocol is a set of rules to ensure successful host-to-host communication
  
• 
  Network protocols define a common set of rules that can be implemented on devices in software
  

• 
  A network protocol is a set of rules and formats that devices use to communicate with each other
  
• 
  It enables two or more devices to communicate over one or more networks
  
• 
  Examples of network protocols include addressing, reliability, flow control, sequencing, error detection, and application interface
  
• 
  Network protocols have one or more functions associated with them
  
• 
  The network requires the use of several protocols, not just one
  

• 
  Devices must agree upon protocols to communicate with each other, just like people must agree upon a language to communicate
  
• 
  If the protocols are not agreed upon, there will be miscommunication and the communication will fail
  

• 
  HTTP (Hypertext Transfer Protocol) governs the way a web server and a web client interact with each other
  
• 
  TCP (Transmission Control Protocol) manages the individual conversations, provides guaranteed delivery, and manages flow control
  
• 
  IP (Internet Protocol) delivers messages globally from the sender to the receiver
  
• 
  Ethernet delivers the message from the network interface card to another network interface card on the same ethernet local area network
  

• 
  Protocols must be able to work with other protocols
  
• 
  A protocol suit is a group of interrelated protocols necessary to perform a communication function
  
• 
  Protocols are viewed in terms of layers, with lower layers concerned with moving data and providing services to upper layers
  

• 
  The above summary is based on the provided text, which is a spoken explanation of network protocols and their functions. It is not a direct transcription, but an attempt to summarize and organize the information in a clear and concise manner.
  

• 
  The application layer includes HTTP for web access
  
• 
  The transport layer includes TCP for transmission control
  
• 
  The internet layer includes IP for addressing and routing
  
• 
  The network access layer includes Ethernet for physical connections
  
• 
  Data is transmitted from the application layer down to the network access layer and sent over the network
  
• 
  The process is reversed at the receiving end, with data being received at the network access layer and transmitted up to the application layer
  
• 
  TCP IP ensures that data is transmitted and received in the correct order and that any lost packets are retransmitted
  

• 
  A user accesses a website using HTTP
  
• 
  The web browser sends a request to the web server using TCP
  
• 
  The web server responds with the website data using TCP
  
• 
  The data is transmitted over the internet using IP
  
• 
  The data is received by the user's device and transmitted up to the web browser using Ethernet or WLAN
  
• 
  The web browser displays the website to the user
  

• 
  TCP/IP model consists of four layers: Application, Transport, Internet, and Network Access
  
• 
  Application layer includes protocols such as DNS, FTP, SMTP, etc.
  
• 
  Transport layer includes TCP and UDP protocols
  
• 
  Internet layer includes IP protocol
  
• 
  Network Access layer includes protocols for different types of network interfaces
  

• 
  A web server encapsulates and sends a web page to a client using TCP/IP communication process
  
• 
  The packet includes Ethernet, IP, TCP, and data
  
• 
  The client de-encapsulates the web page for the web browser
  

• 
  Internet Society (ISOC) promotes the open development and evolution of the internet
  
• 
  Internet Architecture Board (IAB) is responsible for the management and development of internet standards
  
• 
  Internet Engineering Task Force (IETF) develops and maintains internet and TCP/IP technologies
  
• 
  Internet Research Task Force (IRTF) focuses on long-term research related to internet and TCP/IP protocols
  
• 
  Internet Corporation for Assigned Names and Numbers (ICANN) coordinates the IP address allocation, management of domain names, and assignment of other information
  
• 
  IANA (Internet Assigned Numbers Authority) is responsible for the management of IP address allocation, domain names, and other internet protocol resources
  

• 
  Multiple organizations manage electronic and communication standards, such as IEEE and TIA
  
• 
  These standards include IP address allocation, domain name management, and protocol identifiers
  
• 
  Reference models, such as the OSI and TCP/IP models, are used to demonstrate complex network concepts with diagrams
  

• 
  The OSI model has seven layers: application, presentation, session, transport, network, data link, and physical
  
• 
  The data link and physical layers overlap in the OSI model
  
• 
  The OSI model is beneficial for protocol design as it defines a set of rules for protocols at each layer
  

• 
  The TCP/IP model has four layers: application, transport, network, and network access
  
• 
  Some protocols, such as Ethernet, overlap between different layers in the TCP/IP model
  

• 
  Layered models assist in protocol design by defining a set of rules for protocols at each layer
  
• 
  They also provide a clear and defined interface between layers
  

• 
  DHCP, HTTP, DNS, FTP are examples of protocols at the top layer of the OSI and TCP/IP models
  
• 
  IPv4, IPv6, ICMP, ICMPv6 are examples of protocols at the network layer of the TCP/IP model
  
• 
  Ethernet, Wi-Fi, SONET are examples of protocols at the network access layer of the TCP/IP model
  

• 
  The OSI (Open Systems Interconnection) reference model is a conceptual model that divides network communication into seven layers
  
• 
  It was developed by ISO in the 1980s to describe standards for inter-computer communication
  
• 
  It helps break down network functions and troubleshoot issues
  
• 
  It creates standards for equipment manufacturing and allows vendors to focus on specialized areas of network
  
• 
  The seven layers of the OSI model are: Application, Presentation, Session, Transport, Network, Data Link, and Physical
  
• 
  Each layer has a specific function and communicates with the layers above and below it
  

• 
  The topmost layer of the OSI model
  
• 
  It is the interface used by applications
  
• 
  Examples of application layer protocols include HTTP, FTP, SMTP, and DNS
  
• 
  It provides services for process-to-process communication
  
• 
  It is responsible for providing a common language to describe networking functions and capabilities
  

• 
  The fourth layer of the OSI model
  
• 
  It provides a common representation of data transferred between application layers
  
• 
  It is responsible for data conversion, data compression, and data encryption
  
• 
  It ensures that data is in a format that can be understood by the receiving device
  

• 
  The fifth layer of the OSI model
  
• 
  It provides services to the presentation layer and manages data exchange and transfer
  
• 
  It is responsible for establishing, maintaining, and ending communication sessions between applications
  
• 
  It ensures that data is exchanged in a reliable and secure manner
  

• 
  The fourth layer of the OSI model
  
• 
  It provides services to the session layer and is responsible for end-to-end communication between applications
  
• 
  It is responsible for segmentation and reassembly of data, flow control, and error recovery
  
• 
  It ensures that data is delivered reliably and efficiently between applications
  

• 
  The third layer of the OSI model
  
• 
  It provides services to the transport layer and is responsible for routing data between networks
  
• 
  It is responsible for logical addressing, routing, and congestion control
  
• 
  It ensures that data is delivered to the correct destination on the network
  

• 
  The second layer of the OSI model
  
• 
  It provides services to the network layer and is responsible for data transfer between devices on the same network
  
• 
  It is responsible for physical addressing, error detection and correction, and flow control
  
• 
  It ensures that data is transmitted reliably between devices on the same network
  

• 
  The bottommost layer of the OSI model
  
• 
  It provides services to the data link layer and is responsible for the physical connection between devices
  
• 
  It is responsible for data encoding, transmission, and reception
  
• 
  It ensures that data is transmitted and received reliably over the physical medium
  

• 
  It fosters competition by allowing products from different vendors to work together
  
• 
  Prevents technology or capability changes in one layer from affecting the other layers or above
  
• 
  Provides a common language to describe networking functions and capabilities
  

• 
  It is important to understand the OSI model for the Cisco class
  
• 
  It is a seven-layer model that conceptualizes data communication
  
• 
  Helps break down network functions, troubleshoot issues, and create standards for equipment manufacturing
  

• 
  Memorize the layers of the OSI model and their functions
  
• 
  Will help you recall them during an exam
  

• 
  This layer provides network access to applications such as your FTP client or Google Chrome
  
• 
  When you access a website like sunridge.com using HTTPS, your Google Chrome browser is using the application layer to access the data
  

• 
  This layer is used for data formatting such as HTML, JPEG, or MP3
  
• 
  It uses encryption services for online banking and data compression
  

• 
  This layer controls the dialog between computers and starts and ends sessions
  
• 
  It keeps a session separate to prevent data clashes or corruption
  

• 
  This layer describes how data is sent reliably or unreliably
  
• 
  Well-known services such as TCP and UDP operate in this layer, and firewalls typically operate here as well
  

• 
  This layer is known as the logical addressing layer and contains IP addresses
  
• 
  Routers operate at this layer, which is layer number three
  

• 
  This layer is a layer number two, located just below the network layer
  
• 
  It is responsible for error-free transfer of frames from one node to another
  

• 
  The above summary is a simplified explanation of the different layers of the OSI model
  
• 
  For a more in-depth understanding, further study is recommended
  

• 
  Data encapsulation is the process of preparing messages for transmission through a network
  
• 
  It involves breaking up messages into smaller units (segmenting) and interleaving multiple streams of segmented data (multiplexing)
  

• 
  Increases speed by allowing large amounts of data to be sent over the network without tying up a communications link
  
• 
  Increases efficiency by only requiring segments that failed to reach the destination to be re-transmitted, not the entire data stream
  

• 
  The OSI model has more layers than the TCP/IP model, with the network access and application layers of the TCP/IP model being divided into multiple layers in the OSI model
  
• 
  The OSI model specifies which protocol to use when transmitting over a physical medium, while the TCP/IP model does not
  

• 
  The OSI model is the most important model for this course, but students should also be familiar with the TCP/IP model
  
• 
  The OSI model's network access and application layers are divided into multiple layers in the TCP/IP model
  
• 
  The OSI model specifies procedures for accessing the media and physical means for sending data over a network, while the TCP/IP model does not
  

• 
  There is a Packet Tracer simulation activity in the NetAcad that students should work on to understand the layers and how they work
  
• 
  A video on this particular Packet Tracer TCP and OSI model investigation will be made in the future
  

• 
  The network includes the IP address and the data link includes the MAC address
  
• 
  The data link layer ensures the data is error-free and devices such as switches operate in this layer
  
• 
  The network layer includes the IP address and routers operate in this layer
  
• 
  The physical layer provides access to the cable and electrical signals and includes the media such as fiber optics or electrical wires
  

• 
  It is a top-down process where each layer adds its own information to the data
  
• 
  The level above processes the data and passes it down to the next level of the model
  
• 
  This process is repeated until it is sent out as a bit stream
  
• 
  An example of data encapsulation is a web server sending data to an end client
  
• 
  As the data moves up the stack, each layer strips off its header and passes it up to the next level until it is a data stream that the application can process
  

• 
  A PDU has a different name to reflect its new functions when things change during the transmission
  
• 
  In this course, PDUs are named according to the protocols of the TCP/IP model or the OSI model
  
• 
  Examples of PDUs are data, segment, packet, frame, and bits
  
• 
  Each layer of the OSI model has its own PDU
  
• 
  Layer 7: data, Layer 6: data, Layer 5: data, Layer 4: segment, Layer 3: packet, Layer 2: frame, Layer 1: bits
  

• 
  It is the opposite of encapsulation
  
• 
  As the data moves up the stack, each layer strips off its header and passes it up to the next level until it is a data stream that the application can process
  
• 
  An example of de-encapsulation is the system receiving bits and breaking it down to frame, packet, segment, and data
  

• 
  Application protocol includes hypertext transfer protocol (HTTP) and transport protocol includes transmission control protocol (TCP) or user datagram protocol (UDP)
  
• 
  These protocols interact with each other to ensure the data is transmitted and received correctly
  

• 
  The Internet Protocol (IP) is a set of rules that govern the format of data sent over the internet
  
• 
  It includes protocols such as IP, Network Access Protocols, Data Link, and Physical Layers
  
• 
  Data Link layer is responsible for delivering data from one network interface or Network Interface Card (NIC) to the next on the same network
  
• 
  It includes addressing, such as the Data Link layer source and destination address, and the Network layer source and destination addresses
  
• 
  The Transport layer has the destination and source address or the port numbers
  
• 
  Upper layer has the encoded application data
  

• 
  An IP packet contains two IP addresses: the source IP address and the destination IP address
  
• 
  The source IP address is the IP address of the sending device, and the destination IP address is the IP address of the receiving device
  
• 
  An IP address contains two parts: the network portion and the host portion
  
• 
  The network portion, also known as the prefix, indicates the network group which the IP address is a member
  
• 
  The host portion, also known as the interface ID, identifies a specific device within a group
  

• 
  Devices on the same network will have the same number in the network portion of the address but different numbers in the host portion
  
• 
  For example, two devices on the same network may have IP addresses of 192.168.1.110 and 192.168.1.9
  

• 
  An "octet" is a term used to describe a group of 8 binary digits, or bits, in an IP address
  
• 
  IPv4 addressing uses 4 octets, and IPv6 addressing uses 16 octets
  

• 
  The above summary is a simplified explanation of the OSI model and IP addressing. For a more in-depth understanding, it is recommended to study the OSI model, IP addressing, and subnetting in more detail.
  

• 
  Devices on the same network will have the first couple of octets the same and the last one different
  
• 
  Mac addresses are physical addresses embedded into the physical ethernet nic
  
• 
  The source mac address will be that of the originator on the link, the destination mac address will always be the same link as the source
  

• 
  When devices are on the same ethernet network, the data link frame will use the actual mac address of the destination nic
  
• 
  The source mac address will be that of the originator on the link, the destination mac address will always be the same link as the source
  

• 
  The role of the network layer addresses comes into play when the source and the destination have different network portions, meaning they are on a different network
  
• 
  When the final destination is remote, layer 3 will provide layer 2 with the local default gateway ip address, also known as the route address
  

• 
  The default gateway or dgw is the router interface ip address that is part of this lan and will be the door or the gateway to all other remote locations
  
• 
  All devices on the lan must be told about this address or their traffic will be confined to the lan only
  

• 
  The different layers of the OSI model are being used in this scenario: layer 1 (physical), layer 2 (data link), layer 3 (network), and layer 7 (application)
  

• 
  The above summary is based on the provided text, which contains some incomplete sentences and lacks some context. It is always recommended to have proper and complete sentences for better understanding and summarization.
  

• 
  A computer (PC) is connected to a switch, but the default gateway (DGW) is located at a different point in the network, indicated by an orange arrow.
  
• 
  Data link addressing is local addressing, meaning it has a source and destination for each segment or hop of the journey to the destination.
  
• 
  MAC (Media Access Control) addressing is used for the first segment, with the source being the PC's network interface card (NIC) and the destination being the default gateway interface of the first router.
  
• 
  The source and destination MAC addresses change as the data travels through different routers, but the Layer 3 addressing (IP address) remains the same and does not change.
  
• 
  The main concept to understand in this beginning networking course is that the source and destination addresses change in the data link layer as the data travels through different routers.
  
• 
  The packet is not modified, but the frame is changed, meaning the Layer 2 MAC addressing changes, but the Layer 3 IP addressing remains the same.
  

• 
  As the data travels from the source to the destination, the source and destination MAC addresses change at each hop, but the IP addresses remain the same.
  
• 
  For example, the source MAC address changes from the PC's NIC to the first router's exit interface, and then to the second router's exit interface, and so on.
  
• 
  Similarly, the destination MAC address changes from the first router's interface to the second router's interface, and so on, until it reaches the final destination.
  
• 
  The IP addresses, however, do not change and remain the same throughout the journey.
  

• 
  Routers are used to direct the data from the source to the destination by receiving the frame from one interface and sending it out through another interface.
  
• 
  Each router interface has its own MAC address, which is used as the destination MAC address for the incoming frame and as the source MAC address for the outgoing frame.
  
• 
  The IP addresses, on the other hand, remain the same and are used to identify the source and destination of the data in the network layer.
  

• 
  Layer 2 addressing (MAC addressing) is used for local addressing within a segment or hop of the network, and it changes as the data travels through different routers.
  
• 
  Layer 3 addressing (IP addressing) is used for global addressing and remains the same throughout the journey from the source to the destination.
  
• 
  The main difference between the two is that Layer 2 addressing is used for local communication within a segment, while Layer 3 addressing is used for global communication in the network.
  

• 
  Data link layer addressing is important for the correct transmission of data in a network.
  
• 
  The source and destination MAC addresses are used to identify the devices involved in the communication and to ensure that the data is sent to the correct device.
  
• 
  Understanding how the source and destination addresses change in the data link layer is essential for troubleshooting and managing a network.
  

• 
  MAC addresses change from hop to hop in a network, while IP addresses (L3) remain the same as it is a global address
  
• 
  The ultimate destination is the web server, but L2 MAC addressing changes from one segment to the next
  

• 
  Protocols have specific requirements such as message encoding, formatting, encapsulation size, timing, and delivery options
  
• 
  Protocols work together in a protocol suite, such as the TCP/IP protocol suite used for internet communication
  

• 
  Standardization organizations encourage interoperability, competition, and innovation
  
• 
  Examples include IEEE, IETF, and ISO, which have standardized networking devices and protocols
  

• 
  The TCP/IP and OSI models are used to understand networking concepts
  
• 
  The OSI model has seven layers, while the TCP model has four layers
  
• 
  For this course, it is important to understand both models, but the OSI model is more important than the TCP model
  

• 
  Data takes a specific form at any layer, called the Protocol Data Unit (PDU)
  
• 
  There are five different PDUs used in the data encapsulation process: data, segment, packet, frame, and bits
  
• 
  Data access (L2 and L3) provides addressing to move data through the network
  
• 
  The way layers handle addressing depends on whether the source and destination are on the same network or not
  

• 
  It is important to understand the rules and protocols required for sending messages across a network
  
• 
  Standardization organizations have played a crucial role in the development and implementation of networking devices and protocols
  
• 
  Understanding the reference models, such as the TCP and OSI models, is essential for understanding networking concepts
  
• 
  Data encapsulation and addressing are important concepts to understand for network communication