NETWORKING CONCEPTS

• Personal Area Network - commonly uses Bluetooth to connect mice, keyboards, phones, and tablets.
• Local Area Network - A wired network consisting of a switch and network devices in a limited geographical area.
• Virtual LAN - extends beyond a traditional LAN and groups users based on administratively defined boundaries such as department or floor.
• Wireless LAN - connects multiple wireless devices and uses an access point
• Wireless Mesh Network - connects multiple wireless access points together to expand the wireless network.
• Metropolitan Area Network - a network that spans a city
• Wide Area Network - a network that spans a large geographical area
• Virtual Private Network - a method of connecting to a network such as a company network across an unsecure network
• Virtual LANs provide segmentation and organizational flexibility in a switched network.
• VLANs are based on logical connections, instead of physical connections, and they can be segmented based on factors such as function, team, or application.
• Among the various network topologies, in which can group of devices communicate as if each device was attached to the same switch?

  Virtual LAN
• Analog telephone access or Dial-up – uses an analog modem to call another modem.
• Integrated Services Digital Network - more bandwidth than dialup.; can carry voice, video, and data.
• Broadband – uses different frequencies to send multiple signals over media.
• Digital Subscriber Line - always on technology that uses phone lines; voice and data carried on different frequencies; requires a filter on the port that connects to a phone.
• Very high-speed DSL attains much higher bit rates than DSL. A symmetric link can carry as much as 26 Mbps in both directions while an asymmetric link can carry as much as 52 Mbps download and 6 Mbps upload. VDSL2 can carry as much as 100 Mbps in both directions.
• Cable – Uses a cable modem to connect to a traditional cable TV network; shares the network with multiple subscribers.
• Fiber – High bandwidth connection used in backbone networks, large enterprise environments, large data centers, and now part of some home internet connections.
• Line of Site Wireless – always on technology that uses radio signals for connecting to the internet.

  • Clear path required
  • Weather affects signal strength and performance
• Satellite – broadband technology for remote areas

  • Uses a satellite dish
  • Not a good solution for time-sensitive applications like gaming, Voice over Internet Protocol (VoIP), and video conferencing
• Low Earth Orbit – far more satellites orbiting the Earth in low Earth orbit

  • Can support up to approximately 100 Mbps
  • Much lower latency than standard satellite, between 100 and 200 ms
• Cellular – relies on cell towers to create a network used by cell phones and connectivity to the internet
• Mobile Hotspot and Tethering

  • Cell phone option that allows another device to connect to the internet using Wi-Fi, Bluetooth, or USB cable
  • The other device is using the phone’s cellular connection to connect to the internet
• A mobile hotspot is when a cell phone allows Wi-Fi devices to connect and use the mobile data network.
• Transmission Control Protocol - a communications standard for delivering data and messages through networks

  • Three basic operations of reliability
  • Numbering and tracking of data segments
  • Acknowledgment of received data
  • Retransmitting any unacknowledged data after a period of time.
• User Datagram Protocol -  a connectionless communication protocol for transporting packets across networks; a communication protocol used across the Internet for especially time-sensitive transmissions such as video playback or DNS lookups

  • Very little overhead or data checking
  • Best-effort delivery protocol (unreliable)
  • No acknowledgment that the data is received by the destination
• The Domain Name Service protocol finds the IP address associated with a registered Internet domain for Web, Email, and HTTP.
• Hypertext Transfer Protocol provides a set of rules for exchanging text, graphic images, sound, video, and other multimedia files on the World Wide Web.
• Bluetooth - Up to 7 devices to create a PAN• 802.15.1• 2.4 to 2.485 GHz radio frequency range
• Redundant Array of Independent Disks - Passive or active tags used to identify items; 125 MHz to 960 MHz radio frequency range
• Passive RFID Tag - rely on RFID reader to activate andread
• Active RFID Tag - have a battery to broadcast the ID up to 100 meters
• Near Field Communication

  • Devices must be in close proximity to exchange data
  • Used for payments, printing, public parking, etc.
• First Generation or 1G - analog calls only
• Second Generation or 2G - introduced digital voice, conference calls, and caller ID with speeds less than 9.6 kb/s
• 2.5G – supports web browsing, short audio and video clips with speeds up to 237 Kb/s.
• 3G – full motion video and streaming music at speeds up to 2 Mb/s.
• 3.5G – supports high-quality streaming video, high-quality video conferencing, and VoIP, at speeds up to 16 Mb/s.
• 4G - IPv6, IP-based voice, gaming services, high quality multimedia at speeds up to 672 Mb/s.
• Long Term Evolution or LTE – means it meets the 4G speed standards and improves connectivity while in motion; speeds up to 100 Mb/s when mobile and up to 1 Gb/s when stationary.