Understanding Different Network Types

Network Types

• The internet is so ingrained in everyday life that it's often taken for granted.
• People generally view the internet as a collection of connections rather than physical infrastructure; its where people go to find/share information.
• The internet isn't owned by any single entity; it's a global network of interconnected networks that use common standards to exchange information.
• Small home networks link computers and the internet.
• A SOHO (small office/home office) network lets home or remote offices connect to a corporate network and shared resources.
• Medium to large networks, like those for corporations or schools, span many locations with many interconnected hosts.
• The internet is described as a network of networks uniting millions of worldwide computers.
• Smartphones integrate functionalities of phones, cameras, GPS, media players, and touch screens into one device.
• Tablets come with on-screen keyboards enabling tasks like email and web browsing, similar to laptops.
• Smartwatches connect to smartphones to provide alerts, messages, track heart rate, and count steps.
• Wearable computers, such as Google Glass, use a small screen to display information like a fighter pilot's HUD (Head-Up Display).

Connected Home Devices

• Connected security systems allow remote monitoring and configuration of home elements like lighting and climate.
• Household appliances such as refrigerators, ovens, and dishwashers can be connected to the internet.
• Smart TVs can access internet content directly, avoiding the need for traditional TV service equipment.
• Gaming consoles connect to the internet to download games and play with friends.

Other Connected Devices

• Modern Smart Cars can connect to the internet to provide access to maps, audio, video, and destination information.
• Radio frequency identification (RFIDs) tags can be used on objects to track them or monitor sensors.
• Connected sensors offer data on temperature, humidity, wind speed, barometric pressure, and soil moisture, this allows actuators to respond to conditions.
• Medical devices, like pacemakers and insulin pumps, give users/professionals immediate feedback or alert as vital signs.

Data Transmission

• Personal Data Types include volunteered, observed and inferred:
• Volunteered data is explicitly shared by individuals, such as social network profiles, and includes videos, pictures, text and audio.
• Observed data is captured by monitoring individuals' actions, such as location data from cell phones.
• Inferred data, such as a credit score, is based on analysis of volunteered or observed data.
• Computers and networks operate using binary digits (bits), represented by 0 or 1.
• A bit, short for "binary digit," is the smallest unit of data.
• A byte is a group of eight bits representing letters and numbers.
• ASCII (American Standard Code for Information Interchange) represents each character using eight bits; for example, A = 01000001.

Common Data Transmissions

• Data turns into a series of bits, then converts to signals for sending.
• Media refers to the physical medium transmitting signals, e.g., copper wire, fiber-optic cable, electromagnetic waves.
• A signal consists of electrical or optical patterns transmitted from one connected device to another.
• Common methods of signal transmission include:
• Electrical signals that represent data as electrical pulses on copper wire,
• Optical signals that convert electrical signals into light pulses.
• Wireless signals that use infrared, microwave, or radio waves through the air.

Bandwidth and Throughput

• Bandwidth is the data-carrying capacity of a medium; digital bandwidth measures the amount of data transferable over time, in bits per second.
• Units of Bandwidth and their Equivalence:
  • Bits per second (bps): 1 bps = fundamental unit of bandwidth
  • Kilobyte (kbps): 1 kbps = 1,000 bps = 10³ bps
  • Megabyte (Mbps): 1 Mbps = 1,000,000 bps = 10⁶ bps
  • Gigabyte (Gbps): 1 Gbps = 1,000,000,000 bps = 10⁹ bps
  • Terabyte (Tbps): 1 Tbps = 1,000,000,000,000 bps = 10¹² bps
• Throughput measures the transfer of bits across media over a period, but usually doesn't match specified bandwidth due to factors like; connection data, data types, number of intermediate network devices.
• Latency is the time it takes for data to travel between points, accounting for delays.

Clients and Servers

• Clients are computer hosts using installed software to request and display information.
• Servers are hosts running installed software to provide information, like email or web pages.
• Below are the different types of server and description:
  • Email Server that runs email server software.
  • Email Clients use mail client software, such as Microsoft Outlook, to access email residing on the server
  • Web servers run web server software.
  • Web clients use browser software, such as Windows Internet Explorer, to access web pages on the server.
  • File servers store user files in a central location.
  • File clients access these files with client software like Windows File Explorer.
• In a peer-to-peer (P2P) network, computers act as both servers and clients.
• Simple P2P networks connect two computers directly, wired or wirelessly.
• P2P networks are Easy to set up, Less complex and lower cost than other networks, and suitable for tasks like sharing files and printers.
• P2P network disadvantages include: no central administration, are not as secure or scalable, and all devices may act as both clients and a server.
• A P2P application allows a device to function as both client and server.
• P2P applications require a user interface and a background service.
• A single computer can provide services to many computers.
• A single computer can also run multiple types of server software.

Network Components

• Network infrastructure has three hardware categories: end devices, intermediate devices, and network media.
• The network devices that people are most familiar with are called end devices (hosts).
• End devices form the interface between users and the underlying communication network.
• Examples of end devices include:
  • Computers (workstations, laptops, file servers, web servers)
  • Network printers
  • Telephones and teleconferencing equipment
  • Security cameras
  • Mobile devices (smart phones, tablets, PDAs, wireless debit/credit card readers, barcode scanners)