basic connectivity

• Communication is almost as important to us as our reliance on air, water, food, and shelter; through networks, we are connected like never before
• Schaffer and Emerson's 1964 study on attachment aimed to identify stages of attachment and find a pattern in the development of an attachment between infants and parents
• Participants in the study were 60 babies from Glasgow, and the findings showed that babies of parents with 'sensitive responsiveness' were more likely to have formed an attachment
• Freud's superego is the moral component of the psyche, representing internalized societal values and standards
• Every computer on a network is called a host or end device; servers provide information to end devices like email servers, web servers, and file servers; clients send requests to servers to retrieve information
• In a Peer-to-Peer Network, a device can be both a client and a server, but this design is only recommended for very small networks due to security and scalability issues
• End devices are where messages originate from or are received, playing a crucial role in the flow of data through a network
• Intermediary network devices like switches, wireless access points, routers, and firewalls interconnect end devices and manage data flow by regenerating and retransmitting data signals, maintaining network pathways, and notifying devices of errors
• Communication across a network is carried through different media types like metal wires within cables using electrical impulses, glass or plastic fibers within fiber-optic cables using pulses of light, and wireless transmission using modulation of specific frequencies of electromagnetic waves
• Network diagrams, also known as topology diagrams, use symbols to represent devices within the network, illustrating both physical and logical aspects of the network
• Small Home Networks connect a few computers to each other and the Internet, while Small Office/Home Office networks enable computers within a home or remote office to connect to a corporate network
• LANs are network infrastructures that span a small geographical area, while WANs span a wide geographical area, connecting LANs over vast distances
• The internet is a worldwide collection of interconnected LANs and WANs, not owned by any individual or group, and maintained by organizations like IETF, ICANN, and IAB
• An intranet is a private collection of LANs and WANs internal to an organization, accessible only to authorized members, while an extranet provides secure access to a network for individuals from different organizations
• Internet access technologies vary, with popular services for home users including broadband cable, DSL, wireless WANs, and mobile services, while organizations require faster connections for IP phones, video conferencing, and data storage
• Corporate business connections may require higher bandwidth, dedicated connections, and managed services, with options like dedicated leased lines, Ethernet WAN, Business DSL, and Satellite connections
• Converged networks carry data, voice, and video over the same network infrastructure, eliminating the need for separate cabling and technologies for each service
• Network architecture refers to the technologies supporting the infrastructure that moves data across the network, addressing fault tolerance, scalability, quality of service, and security to meet user expectations
• A fault-tolerant network limits the impact of failures by having multiple paths for data transmission, providing redundancy through packet switching networks that split traffic into packets routed over different paths
• Scalable networks can expand quickly to support new users and applications without impacting existing services, following standards and protocols to ensure scalability
• Voice and live video transmissions require higher expectations for quality of service to deliver seamless services without interruptions caused by bandwidth limitations
• Quality of Service (QoS) is the primary mechanism used to ensure reliable delivery of content for all users
• With a QoS policy in place, the router can more easily manage the flow of data and voice traffic
• Network security involves two main types: Network infrastructure security and Information Security
• Three goals of network security are:

  • Confidentiality – only intended recipients can read the data
  • Integrity – assurance that the data has not been altered during transmission
  • Availability – assurance of timely and reliable access to data for authorized users
• Recent networking trends affecting organizations and consumers include: Bring Your Own Device (BYOD), Online collaboration, Video communications, and Cloud computing
• Bring Your Own Device (BYOD) allows users to use personal tools like laptops, smartphones, and tablets to access information and communicate
• Online Collaboration tools like Cisco WebEx Teams enable instant messaging, image posting, video sharing, and links sharing for businesses and education
• Video Communication, like Cisco TelePresence, is a powerful tool for effective collaboration and communication regardless of location
• Cloud Computing allows storing personal files or backing up data on servers over the internet, enabling access to applications from anywhere
• Four types of Clouds are: Public Clouds, Private Clouds, Hybrid Clouds, and Custom Clouds, each serving different purposes
• Smart home technology integrates technology into everyday appliances, allowing interconnectivity with other devices for enhanced functionality
• Powerline Networking enables devices to connect to a LAN using electrical outlets when data network cables or wireless communications are not feasible
• Wireless Broadband, in addition to DSL and cable, connects homes and small businesses to the internet using cellular technology and antennas installed outside the house
• Network security must be implemented in multiple layers using various security solutions, such as antivirus software, firewall filtering, dedicated firewall systems, and more
• The Cisco Certified Network Associate (CCNA) certification demonstrates knowledge of foundational technologies and skills needed for next-generation technologies
• Network architecture refers to the technologies supporting the infrastructure and the protocols moving data across the network
• Common external threats to networks include viruses, worms, spyware, and denial of service attacks, while internal threats can be lost or stolen devices and accidental misuse by employees
• Larger networks require additional security measures like dedicated firewall systems, access control lists, intrusion prevention systems, and virtual private networks
• Network diagrams use symbols to represent devices and connections, aiding in understanding how devices connect in a network