Network Today

• Networks Connect Us

  No Boundaries: World without boundaries, Global communities, Human network
• Network Components

  Peer-to-Peer: Device can be a client and a server in a Peer-to-Peer Network. Easy to set up, less complex, lower cost, used for simple tasks like transferring files and sharing printers. Not as secure, not scalable, slower performance.
• Network Components

  Intermediary Network Devices: Interconnect end devices. Examples include switches, wireless access points, routers, and firewalls. Manage data flow through the network by regenerating and retransmitting data signals, maintaining information about network pathways, and notifying other devices of errors and communication failures.
• Network Representations and Topologies

  Network Representations: Network diagrams, often called topology diagrams, use symbols to represent devices within the network. Important terms include Network Interface Card (NIC), Physical Port, Interface.
• Network Components

  Host Roles: Every computer on a network is called a host or end device. Servers provide information to end devices like email servers, web servers, file servers. Clients send requests to servers to retrieve information.
• Network Representations and Topologies

  Topology Diagrams: Physical topology diagrams illustrate the physical location of intermediary devices and cable installation. Logical topology diagrams illustrate devices, port
• Network Components

  Network Media: Communication across a network is carried through a medium which allows a message to travel from source to destination. Media types include metal wires within cables using electrical impulses, glass or plastic fibers within cables (fiber-optic cable) using pulses of light, and wireless transmission using modulation of specific frequencies of electromagnetic waves.
• Networks Affect Our Lives

  Communication is almost as important to us as our reliance on air, water, food, and shelter. In today’s world, through the use of networks, we are connected like never before.
• Network Components

  End Devices: Where a message originates from or where it is received. Data flows through the network and arrives at an end device.
• Common Types of Networks
• LANs and WANs
• Physical topology diagrams illustrate the physical location of intermediary devices and cable installation
• The Internet is a worldwide collection of interconnected LANs and WANs
• An intranet is a private collection of LANs and WANs internal to an organization meant to be accessible only to the organization's members or others with authorization
• A LAN is a network infrastructure that spans a small geographical area
• LAN


  Interconnect end devices in a limited area
• Home and Small Office Internet Connections

  • Cable - high bandwidth, always on, internet offered by cable television service providers
  • DSL - high bandwidth, always on, internet connection that runs over a telephone line
  • Cellular - uses a cell phone network to connect to the internet
  • Satellite - major benefit to rural areas without Internet Service Providers
  • Dial-up telephone - an inexpensive, low bandwidth option using a modem
• Internet Access Technologies
• Network Representations and Topologies
• A WAN is a network infrastructure that spans a wide geographical area
• LANs and WANs

  • Local Area Network (LAN)
  • Wide Area Network (WAN)
• Logical topology diagrams illustrate devices, ports, and the addressing scheme of the network
• Groups maintaining structure on the internet

  • IETF
  • ICANN
  • IAB
• Common Types of Networks

  • Small Home Networks - connect a few computers to each other and the Internet
  • Small Office/Home Office - enables computer within a home or remote office to connect to a corporate network
  • Medium to Large Networks - many locations with hundreds or thousands of interconnected computers
  • World Wide Networks - connects hundreds of millions of computers worldwide - such as the internet
• WAN


  Interconnect LANs over wide geographical areas
• An organization might use an extranet to provide secure access to their network for individuals who work for a different organization that need access to their data on their network
• Internet Access Technologies for home users and small offices

  • Broadband cable
  • Broadband digital subscriber line (DSL)
  • Wireless WANs
  • Mobile services
• Businesses Internet Connections

  • Dedicated Leased Line - reserved circuits within the service provider’s network that connect distant offices with private voice and/or data networking
  • Ethernet WAN - extends LAN access technology into the WAN
  • DSL - available in various formats including Symmetric Digital Subscriber Lines (SDSL)
  • Satellite - provides a connection when a wired solution
• The Wealth of Nations was written

  2016
• Types of connections for distant offices

  • Voice networking
  • Data networking
• Formats of Business DSL

  • Symmetric Digital Subscriber Lines (SDSL)
• Network Architecture refers to the technologies that support the infrastructure that moves data across the network
• A fault-tolerant network limits the impact of a failure by limiting the number of affected devices. Multiple paths are required for fault tolerance
• A scalable network can expand quickly and easily to support new users and applications without impacting the performance of services to existing users
• Converged data networks

  Carry multiple services on one link including data, voice, video
• Network security must address network infrastructure security, physical security of network devices, preventing unauthorized access, and information security
• Bring Your Own Device (BYOD) allows users to use their own devices giving them more opportunities and greater flexibility
• The role of the network must adjust and continually transform to keep up with new technologies and end-user devices as they constantly come to the market
• Before converged networks, an organization would have been separately cabled for telephone, video, and data. Each of these networks would use different technologies to carry the signal
• Satellite can provide a connection when a wired solution is not available