BBA113-003 (Prof. Gyanesh Raj)

Internet definition and architecture

• The internet is a decentralized network made up of many physical devices.
• It is essentially a network of networks, connecting different types of networks such as:
  • Private networks
  • Public networks
  • Government databases
  • Academic databases
• No single person or organization “governs” it.

How a web search/request works (5-step journey)

1. You type/search on your device.
2. Your request goes to the router.

3. The router forwards it to the ISP (Internet Service Provider) (examples given: Airtel, BSNL, Jio).

4. The request uses DNS (Domain Name System) to find the server’s IP address.

   • DNS is compared to a phonebook: you access a site name, but the system uses the underlying IP address.
5. The request reaches the web server, which returns the response to your device—appearing quickly on your screen.

Device-to-server communication language: HTTP vs HTTPS

• Devices and servers use HTTP (Hypertext Transfer Protocol) to communicate.

HTTP (not secure)

• Data can be visible to others because it’s publicly accessible.

HTTPS (secure)

• The “S” stands for secure, meaning the connection is encrypted/secure.
• Others cannot see what you requested or sent (analogy: HTTP = “shouting”, HTTPS = “whispering”).

Practical guidance included:

• When entering passwords or sensitive data, check the browser address bar to see whether the site uses HTTP or HTTPS.

Why the internet “lags” or buffers: bandwidth vs speed

Buffering/lag is attributed to connection performance, specifically bandwidth and actual speed.

• Bandwidth = the maximum possible capacity of the connection (compared to the width of a pipe).

• Speed = the actual data transfer rate at a given moment (how much water actually flows).

Measurement units mentioned:

• Gbps, Mbps, Kbps (gigabits/megabits per second, etc.)

Upload vs download speed

• Upload speed: how fast your device sends data to the server.
• Download speed: how fast your device receives data from the server.

Since most internet use involves downloading (e.g., YouTube, music streaming, searching), download speed matters more for typical performance.

If upload/download speed is low:

• uploads/downloads happen slowly, and
• services like video playback can lag/buffer.

Practical self-check / conclusion prompts

The speaker instructs viewers to:

• Check the site they’re using: HTTP or HTTPS.
• If buffering occurs, infer it’s likely due to insufficient upload or download speed.

Conclusion summarizes:

• What the internet is,
• How web requests work,
• What HTTP/HTTPS mean,
• How to think about measuring internet connection speed.

Main speaker

• Professor Gyanesh Raj (Prof. Gyanesh Raj)