Thursday Open Technology Lab · Week 5

How Does the Internet Get From Here to There?

Ask · Learn · Build

Follow a website request through local connections, DNS, packets, routers, and services. Distinguish Wi-Fi from internet access, then deliver three paper packets and test an alternate route when a router fails.

Session date: October 29, 2026. A free, self-guided lesson at every level. Paper and pencil are enough; a phone is optional. No computer, account, registration, payment, or prior experience is required.

This week's replay

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The original 31-slide lecture

The complete lecture follows a website request, explains DNS, packets, routing, HTTP and HTTPS, and includes a paper lab, worked solutions, optional deeper paths, and learning checks. These are the original, unmodified PDF and editable PowerPoint in their original order.

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One website, many networks

Imagine entering gunnchos.com in a browser. Your device, a local connection, address lookup, networks that forward data, a responding service, and software that renders the result all cooperate. Week 1 mapped a system, Week 2 followed a tap, Week 3 investigated performance, and Week 4 explored hardware and software. Week 5 follows the data outside the device and back.

Wi-Fi, the internet, and the web

Wi-Fi: A local wireless connection between a device and an access point. Full Wi-Fi bars do not guarantee working internet access.
Internet: A network of networks exchanging data using common protocols. Your provider connects to independently operated networks, peers, content providers, and CDNs.
Web: One application family using the internet. Browsers request pages and resources using HTTP/HTTPS. Email, games, and calls also use the internet; not every internet service is a webpage.

The route at a glance

Your device → Wi-Fi or cellular access → local gateway → ISP → other networks → service. A home box may combine Wi-Fi, routing, switching, and modem functions. Provider access can use cable, fiber, cellular, fixed wireless, or another connection. The response needs a route back, which may differ from the outward path.

Names and addresses: DNS

Humans remember a domain name such as gunnchos.com. DNS helps resolve that name to records such as IP addresses. A cached answer may avoid further lookups; otherwise a resolver asks DNS infrastructure. Answers may change or include multiple addresses. DNS finds an address; it does not download the webpage.

The lecture’s address 203.0.113.7 is reserved for documentation and is an illustrative example, not the real address of gunnchos.com.

Packets and the next hop

Data travels in manageable packets carrying addressing and control information along with content. A router reads destination information and uses its forwarding table to choose the next hop or outgoing interface. It forwards the packet, or may discard it when forwarding is not possible. It usually decides the next step rather than the entire end-to-end route.

Packets can be delayed, lost, or arrive out of order. Recovery and reassembly depend on transport and application behavior. An alternate path helps only if it is available and selected; route changes are not guaranteed or immediate.

HTTP, HTTPS, and the browser

A browser acts as a client requesting a resource by URL and method, often GET. A server, CDN, or service returns a status and content or an error. The browser processes HTML, styles, scripts, images, and other resources. A page often needs several requests and may use nearby caches. HTTP/1.1 and HTTP/2 commonly use TCP; HTTP/3 uses QUIC.

HTTPS usually encrypts communication between the client and the authenticated endpoint, protects integrity in transit, and uses certificate checks to help authenticate the server connection. It does not guarantee that a site is trustworthy, prevent every scam, or hide all connection metadata.

A website in seven moves

Type a name
Find an address with DNS
Connect
Send a request
Route packets
Get a response
Display the page

This is a conceptual common case. Real routes, service locations, caches, protocols, and timing vary; it is not a measured trace of this website.

When it fails, ask where in the journey

Symptoms are clues, not proofs of a specific cause. Observe → locate → test → learn.

Wi-Fi connected, pages never load: Possible causes: Gateway, DNS, provider connection, or remote service.
One website fails; others work: Possible causes: Site, DNS entry, account, or browser issue.
Some pages load, others are slow: Possible causes: Large assets, congestion, caching, or device limits.
A video call freezes; email works: Possible causes: Real-time sensitivity, jitter, loss, or app behavior.

Ask who is requesting, which address or service is contacted, which networks carry the data, what request and response travel, and which boundary may be failing or slow.

Deliver three paper packets

Use paper and pencil for a five-minute recap challenge, or take ten minutes for the full lab. No device or network access is needed. These routes are fictional teaching examples.

Draw D (Device), H (Home router), A, B, C, E (Routers), and S (Service). Connect only D-H, H-A, A-B, B-S, A-C, C-E, and E-S.
Make three paper messages, P1, P2, and P3, each with source D and destination S.
Move P1 along D → H → A → B → S. Write the visited nodes and count the links.
Cross out B and its connected links. Move P2 and P3 along another available D-to-S route, without jumping between unconnected nodes.
Write the new route, compare link counts, and explain what must change at A. Discuss whether a real network always recovers instantly.

Reveal the worked routes and link counts

Round 1: D → H → A → B → S crosses four links. Round 2: D → H → A → C → E → S crosses five links and avoids B. A backup path must be available and selected. Real recovery depends on routing state, policy, and time; some traffic may fail.

Success check: Can someone follow your labeled route without jumping across a missing link? Explain why the second route avoids B, how its link count differs, and what the exercise cannot prove about a real network.

Optional phone observation: Look at whether you are using Wi-Fi or cellular access. Try a harmless public webpage and record an observation such as “Connected to Wi-Fi; public site loads slowly.” Keep addresses, passwords, Wi-Fi details, and account information private. Do not change school or work settings or run network scans without authorization.

Choose your lane

Each lane is a depth you can choose. None of them is worth more than the others. You can participate without a computer. A paper drawing is valid. A phone photo can be used later, when submissions open.

Explorer

Explain how a website reaches a phone.

Week 5

Distinguish Wi-Fi, the internet, and the web in your own words.
Draw the device, local network, provider, other networks, and destination service.
Explain the jobs of DNS and a router.

Builder

Test a route and design more reliable access.

Week 5

Deliver the three paper packets and compare the primary and alternate paths.
For a community library, draw device → Wi-Fi → gateway → ISP → service and mark three possible failure points.
Propose one low-cost improvement and one way to distinguish coverage, capacity, DNS, and remote-site problems.

Engineer / Researcher

Question routing, protocols, and evidence.

Week 5

Investigate DNS caching and stale answers, forwarding tables, routing policy, and failure recovery.
Compare TCP and QUIC; explain what ping or traceroute can reveal and cannot prove.
State a hypothesis, an observation, a test, and its limitations. Describe what HTTPS protects and what threats remain.

This is an educational depth lane, not enrollment in human-subjects research.

Check your understanding

Is Wi-Fi access exactly the same as internet access?
Does DNS download a webpage, or help find an address?
What is a router’s immediate forwarding decision?
If a route fails, will every packet instantly find a new route?

Reveal the lecture’s explanations

No. Wi-Fi connects local devices; the gateway or provider can still be unavailable.
DNS helps find an address. HTTP fetches resources.
A router chooses a next hop using destination information and a forwarding table.
No guarantee. An alternate path, routing state, and sufficient time are needed; some traffic may fail.

Keep your route map yourself. This page collects no responses or files. Uploads remain closed; participation does not enroll you in research.

All 31 slides as text

Read the original PowerPoint text in slide order. The labeled network and its exact connections are also described in the paper activity above. The original PDF preserves the visual layout.