Your browser sends a request starting with GET /index.html. Which layer chops it into numbered segments?

• The Internet layer, which adds addresses
• The transport layer, which numbers pieces
• The link layer, which adds the local header

Which layer moves raw bits across a wire, a wifi signal or fiber?

• The physical layer
• The transport layer
• The application layer

On the receiving computer, each layer removes only the header it understands.

A request is wrapped once by TCP, once by IP, and once by the link layer. How many headers does it carry on the wire?

A cable fails, the router picks another path, and your page arrives a little late. What happened?

• The application layer rerouted the packets
• The message was lost because one path broke
• A lower layer handled it, app saw a delay

You inspect a captured packet and find a header with a source and a destination address. Which layer added it?

• The application layer
• The Internet layer
• The transport layer

A log reads: segment 5 missing, asking the sender to resend it. Which layer speaks here, and why?

• The transport layer, because it numbers pieces and fills gaps
• The Internet layer, because it picks routes
• The application layer, because it shows the page

Engineers replace old copper with fiber, and no app needs rewriting. What earns that freedom?

• The wire understands web requests
• Fiber needs no headers at all
• Each layer trusts only its neighbors, so the bottom can change alone