4 Internet History: Web, Mobile, and IoT

fundamentals

history

internet

4.1 Start With the Decision

This section: Start With the Decision — The web made linked pages easy to reach.

The web made linked pages easy to reach. Mobile, cloud, and IoT then moved that reach into daily devices and services.

4.2 Route Overview

This section: Route Overview — This is part 2 of 2.

This is part 2 of 2. Review Internet History: ARPANET and TCP/IP for the preceding evidence.

4.3 Learning Objectives

This section: Learning Objectives

Connect DNS and the web to human use of the Internet.
Compare the web, mobile-cloud, and IoT eras.

4.4 Chapter Roadmap

This section: Chapter Roadmap

Checkpoint: TCP/IP and DNS
The World Wide Web (1991-1999)
The Mobile and Cloud Era (2000-2015)
The IoT Era (2015-Present)
Checkpoint: Web to IoT
Timeline: 55 Years of Networking
The Unsung Heroes
See Also
Common Pitfalls
Knowledge Check
Deep Dive: Packet Switching, Layers, and the IP Narrow Waist
Summary
What’s Next
Key Takeaway

Physics Phoebe, Physics and measurement-foundations expert

Checkpoint: TCP/IP and DNS

You now know:

January 1, 1983 matters because ARPANET switched from NCP to TCP/IP in one coordinated Flag Day.
DNS changed numeric addressing into names such as usc.edu, while IoT deployments still need to plan cache TTLs and failover names.
The Internet became practical because BSD Unix, NSFNET, and open protocols let more hosts join without redesigning every application.

4.5 The World Wide Web (1991-1999)

This section: The World Wide Web (1991-1999)

4.5.1 Tim Berners-Lee’s Gift to Humanity

Tim Berners-Lee, a British scientist at CERN (the European particle physics laboratory), was frustrated that researchers couldn’t easily share documents across different computer systems. In 1989, he proposed a system combining three ideas:

HTML (HyperText Markup Language) — a way to format documents
HTTP (HyperText Transfer Protocol) — a way to request and send documents
URLs (Uniform Resource Locators) — a way to address any document on any server

The first website was hosted at CERN at http://info.cern.ch in 1991. CERN put the World Wide Web software in the public domain on 30 April 1993, helping independent developers and institutions adopt it.

4.5.2 The Browser Wars and Explosive Growth

1993: Marc Andreessen and Eric Bina release Mosaic, an influential graphical web browser
1994: Andreessen co-founds Netscape. Amazon and Yahoo are founded
1995: JavaScript created by Brendan Eich in 10 days. Internet Explorer launched. eBay founded
1996: Larry Page and Sergey Brin begin the BackRub project at Stanford (later renamed Google)
1998: Google incorporated. HTTP/1.1 was already in use; RFC 2616 followed in 1999
1999: Kevin Ashton coins “Internet of Things” in a presentation at Procter & Gamble

Putting Numbers to It

The growth of the Web was unlike anything before. The site counts are historical estimates (Internet Live Stats; Netcraft’s June 2000 survey counted just over 17 million hostnames), and the user counts are estimates, not a count of Web users specifically.

Year	Websites	Internet Users	Growth Rate
1991	1	~4 million	—
1993	130	~14 million	130x sites
1995	23,500	~40 million	181x sites
1997	1 million	~120 million	43x sites
2000	17 million	~413 million	17x sites

From 1 website to 17 million in just 9 years — compound annual growth rate of approximately $\text{CAGR} = \left(\frac{17{,}000{,}000}{1}\right)^{1/9} - 1 \approx 536\%$ per year.

Interactive CAGR Calculator: Try calculating compound annual growth rate for different Internet metrics:

Quick Check: Test your understanding of the World Wide Web:

4.6 The Mobile and Cloud Era (2000-2015)

This section: The Mobile and Cloud Era (2000-2015)

4.6.1 From Desktop to Pocket

2001: Wikipedia launches — collaborative knowledge on the Internet
2003: Skype launches — VoIP goes mainstream
2004: Facebook launches. Web 2.0 emerges (user-generated content)
2007: Apple iPhone released — the smartphone revolution begins
2008: Android launched. GitHub founded. First Bitcoin paper published
2010: Instagram launches. iPad introduced. “Cloud computing” enters mainstream vocabulary
2013: Cisco estimated about 10 billion connected things; definitions and forecasts differ by publisher

4.6.2 The Seeds of IoT

Several parallel developments in this era made IoT possible:

Cheap, ultra-low-power compute: ARM’s Cortex-M series (first released 2004) put a 32-bit processor with as little as 8 KB of RAM and sub-microamp sleep currents within reach of mass-market embedded devices
Cheap sensors: Mass production brought lower-cost MEMS accelerometers within reach of embedded projects
Low-power wireless: Bluetooth Low Energy (BLE) arrived in the Bluetooth 4.0 specification in 2010; sending about one small packet a second for roughly a year on a coin cell is an illustrative estimate, depending on radio current, packet duration, overhead, and cell capacity
Cloud platforms: AWS IoT (2015), Azure IoT Hub (2015), Google Cloud IoT (2017)
IPv6: With $2^{128}$ addresses ( $3.4 \times 10^{38}$ ), every grain of sand on Earth could have its own IP address

4.7 The IoT Era (2015-Present)

This section: The IoT Era (2015-Present)

4.7.1 Kevin Ashton’s Vision Realized

When Kevin Ashton coined “Internet of Things” in 1999, he was working on RFID supply chain tracking at Procter & Gamble. His insight was simple but profound: computers depend on humans to input data, but most of the real world isn’t in any database. If machines could sense the physical world directly, they could manage things far more efficiently.

Today, that vision is becoming reality:

Metric	2015	2020	2025 (estimate)
Active IoT device connections	3.6 billion	11.3 billion	21.1 billion

Source: IoT Analytics’ 2021 historical estimates (2015; revised 2020 actual) and October 2025 year-end estimate. These are IoT connections, not all Internet-connected devices. Spending and data-volume forecasts are omitted because the earlier figures had no named source or consistent measurement scope.

4.7.2 The People Behind IoT Protocols

The IoT revolution built on protocols designed by dedicated engineers:

Protocol	Creator(s)	Year	Key Innovation
MQTT	Andy Stanford-Clark (IBM), Arlen Nipper	1999	Publish-subscribe for unreliable networks
CoAP	Zach Shelby and Carsten Bormann, with the IETF CoRE working group	2014 (RFC 7252)	REST-style exchanges for constrained devices
6LoWPAN	Geoff Mulligan and Nandakishore Kushalnagar, with the IETF 6LoWPAN working group	2007 (RFC 4944)	IPv6 over low-power wireless
LoRaWAN	LoRa Alliance	2015 (version 1.0)	Long-range, low-power wide-area networking
Matter	Connectivity Standards Alliance	2022 (version 1.0)	Application-layer smart-home interoperability
Thread	Thread Group	2015 (version 1.0)	IPv6 mesh networking for IoT

This section:

Checkpoint: Web to IoT

You now know:

The Web is an application on top of the Internet, not the Internet itself.
Historical estimates put Web growth from 1 website in 1991 to about 17 million sites in 2000; IoT Analytics estimated 3.6 billion active IoT connections in 2015 and later reported 11.3 billion for 2020.
MQTT, CoAP, 6LoWPAN, LoRaWAN, Matter, and Thread extend the older packet, layer, and open-standard pattern into constrained devices.

Quick Check: Test your understanding of Internet pioneers and their contributions:

4.8 Timeline: 55 Years of Networking

This section: Timeline: 55 Years of Networking

1957 ━━ Sputnik launched → ARPA created (1958)
1961 ━━ Kleinrock publishes packet network theory
1962 ━━ Baran designs distributed networks at RAND
1965 ━━ Davies coins "packet switching" at NPL
1969 ━━ ARPANET: first message "LO" (UCLA → SRI)
1971 ━━ Email invented by Tomlinson (@)
1973 ━━ First international ARPANET connections
1974 ━━ Cerf & Kahn publish TCP paper
1978 ━━ TCP split into TCP + IP
1983 ━━ "Flag Day" — TCP/IP becomes Internet standard
      ━━ DNS invented by Mockapetris
1985 ━━ First .com domain (symbolics.com)
1986 ━━ NSFNET backbone (56 Kbps)
1989 ━━ Berners-Lee proposes the World Wide Web
1991 ━━ First website goes live at CERN
1993 ━━ Mosaic browser — the Web goes graphical
1995 ━━ JavaScript, Internet Explorer, eBay
1998 ━━ Google incorporated
1999 ━━ Kevin Ashton coins "Internet of Things"
      ━━ MQTT protocol created at IBM
2004 ━━ Facebook launched
2007 ━━ iPhone released, 6LoWPAN standardized
2010 ━━ Bluetooth Low Energy standardized
2014 ━━ CoAP standardized (RFC 7252)
2015 ━━ LoRaWAN 1.0 released
2020 ━━ 11.3 billion IoT connections (IoT Analytics revised actual)
2022 ━━ Matter 1.0 — smart-home interoperability standard
2025 ━━ 21.1 billion IoT connections (IoT Analytics estimate, October 2025)

Quick Check: Place these Internet milestones in the correct chronological order:

4.9 The Unsung Heroes

This section: The Unsung Heroes

Many crucial Internet pioneers rarely appear in popular histories:

Radia Perlman — Invented the Spanning Tree Protocol (STP) that prevents network loops. Called “Mother of the Internet”
Elizabeth Feinler — Ran the ARPANET Network Information Center, managing the naming system before DNS
Bob Metcalfe — Invented Ethernet at Xerox PARC in 1973, connecting devices over local networks
Jon Postel — Managed Internet Assigned Numbers Authority (IANA) for decades, edited most early Internet standards (RFCs)
Steve Crocker — Wrote the first RFC (Request for Comments) in 1969, establishing the Internet’s open standards culture
Geoff Huston — Pioneered Internet governance and routing analysis

How It Works: From ARPANET’s First Packet to Your IoT Sensor

The big picture: When your IoT temperature sensor sends a reading today, it follows the SAME fundamental process invented in 1969 — just billions of times faster.

Step-by-step breakdown:

Your sensor generates data: A temperature reading of 23.5°C (just like Charley Kline typing “L-O-G-I-N”)
TCP/IP wraps it in layers: Application data → TCP segment → IP packet → Ethernet frame (Cerf & Kahn’s 1974 design)
DNS resolves the server name: “iot-server.example.com” → 93.184.216.34 (Mockapetris’s 1983 invention)
Packets route through the Internet: Each packet finds its own path, just like Baran envisioned in 1962
The server receives and processes: Using HTTP/MQTT/CoAP — protocols standing on 50+ years of evolution

Why this matters: The Internet wasn’t designed by one person or one company. It was built collaboratively by thousands of researchers who shared their work freely. That culture of openness — embodied in the RFC process started by Steve Crocker in 1969 — is why IoT protocols like MQTT and CoAP are also open standards that anyone can implement.

Concept Relationships: Internet History

Concept	Relates To	Relationship
Packet switching	Circuit switching	Packet switching replaced circuit switching as the fundamental network paradigm
TCP/IP	OSI model	TCP/IP is the practical implementation that won over the theoretical OSI model
ARPANET	Internet	ARPANET was the prototype; the Internet emerged when TCP/IP connected multiple networks
World Wide Web	Internet	The Web runs ON the Internet — it’s an application, not the network itself
IoT protocols	TCP/IP	MQTT, CoAP, and 6LoWPAN are modern adaptations of the TCP/IP architecture for constrained devices

Cross-module connection: The layered protocol architecture discussed here is formalized in OSI and TCP/IP Models. The constrained IPv6 adaptation used by many low-power networks is covered in IPv6 and 6LoWPAN.

4.10 See Also

This section: See Also

OSI and TCP/IP Models — Deep dive into the layered architecture Cerf and Kahn designed
Systems Evolution to IoT — How computing economics enabled IoT
IoT History and Paradigm Shifts — Lessons from technology adoption patterns
MQTT Publish-Subscribe Basics — The lightweight IoT messaging pattern born from this history
IPv6 and 6LoWPAN — Modern addressing and adaptation for constrained networks

Try It Yourself: Internet History Timeline

Time: ~10 minutes | Difficulty: Beginner | No hardware needed

Challenge: Create a personal “Internet history” timeline showing how networking technology has affected YOUR life.

Steps:

List 5 Internet-enabled services you use daily (social media, streaming, smart home, etc.)
For each one, trace it back to the historical innovation that made it possible (e.g., Netflix → Web → HTTP → TCP/IP → ARPANET)
Calculate: How many of the 1969-1999 innovations from this chapter does each service depend on?
Identify which service would STOP WORKING first if you removed innovations in reverse chronological order

Hint

Start with the most recent innovation (e.g., Matter/Thread for smart home) and trace backwards. You’ll find that ALL modern services ultimately depend on TCP/IP (1974) and packet switching (1962).

Solution

Every Internet-connected service depends on at least these 5 foundational innovations:

Packet switching (1962) — without it, no shared network
TCP/IP (1974/1978) — without it, no universal protocol
DNS (1983) — without it, you’d need to memorize IP addresses
HTTP/HTML (1991) — without it, no web interfaces
Wi-Fi/cellular (various) — without it, no mobile access

Smart home devices additionally depend on MQTT (1999), BLE (2010), and IPv6 (1998).

4.11 Common Pitfalls

This section: Common Pitfalls

Pitfall 1: Treating the Web and the Internet as the Same Thing

The Web is an application that runs on the Internet. IoT systems often use Internet connectivity without using web pages at all; they may send MQTT, CoAP, DNS, NTP, or device-management traffic over the same packet network.

Pitfall 2: Assuming TCP/IP Was a Single Finished Invention

TCP/IP evolved through research, papers, implementation pressure, and operational cutover. The split between IP and TCP, the later use of UDP, and the growth of DNS all show why Internet architecture is best read as a set of design decisions, not a single launch event.

Pitfall 3: Copying Old Dates Without the Architecture Lesson

The important point is not only that ARPANET began in 1969 or that Flag Day happened in 1983. The engineering lesson is that open protocols, layered boundaries, packet forwarding, and interoperable implementations let independent networks become one Internet.

4.12 Knowledge Check

This section: Knowledge Check

4.13 Deep Dive: Packet Switching, Layers, and the IP Narrow Waist

This section: Deep Dive: Packet Switching, Layers, and the IP Narrow Waist — The Internet that IoT rides on rests on two ARPANET-era ideas.

The Internet that IoT rides on rests on two ARPANET-era ideas. The first is packet switching: instead of reserving a dedicated circuit, data is chopped into independently addressed packets that the network routes hop by hop, sharing links efficiently and rerouting around failures. The second is layering: the protocol stack is split into layers, each with one job, so they can evolve independently.

The TCP/IP model has four layers: link, internet, transport, and application. A sensor sending a reading and a browser loading a page use the same four layers; only the application protocol differs. Understanding that stack is the key to understanding every IoT protocol above it.

4.13.1 The Four Layers and Encapsulation

Each TCP/IP layer wraps the layer above it in its own header, a process called encapsulation:

Layer	Job	Examples
Application	The actual message semantics	HTTP, MQTT, CoAP
Transport	End-to-end delivery and ports	TCP, UDP
Internet	Addressing and routing across networks	IP (IPv4/IPv6)
Link	Delivery over one physical hop	Ethernet, Wi-Fi, IEEE 802.15.4

A sensor sending {"temp":21.4} illustrates the process. The application layer defines that message; the transport layer, perhaps UDP, adds source and destination ports; the internet layer adds IP addresses so routers can forward it; the link layer adds a frame header for the next physical hop. At the receiver, the headers are peeled off in reverse.

An ordinary IP router forwards primarily using IP header fields, so the network can carry many application protocols. Firewalls and other middleboxes may inspect more than the IP header.

4.13.2 Why the Core Stays Simple

The Internet’s most consequential design choice is the end-to-end principle: keep the network core simple so it just forwards packets, and put intelligence such as reliability, ordering, encryption, and application meaning in the endpoints. A router does not track your whole conversation; TCP in your device handles retransmission. This is why anyone can invent a new application protocol without asking the network for permission.

The stack also has a famous narrow waist. Many link technologies sit below and many applications sit above, but everything meets at IP in the middle. Ethernet, Wi-Fi, cellular, and IEEE 802.15.4 can all carry IP, and HTTP, MQTT, CoAP, DNS, and many other protocols can all ride above it.

That narrow waist is what let IoT grow on the existing Internet. A constrained radio and a data-center server interoperate because both meet at IP, with technologies such as 6LoWPAN carrying IPv6 even over tiny 802.15.4 frames.

A CoAP-based sensor can talk to a cloud service written years earlier. Neither the routers between them nor the link technologies they use were designed for CoAP, yet it works because CoAP rides UDP, UDP rides IP, and the simple IP-forwarding core carries it unchanged. The end-to-end principle and the IP narrow waist are the reason IoT could be built on the existing Internet rather than on a separate network.

4.14 Summary

This section: Summary

The Internet’s journey from 4 ARPANET nodes in 1969 to an estimated 21.1 billion active IoT connections in 2025 (IoT Analytics, October 2025 forecast) was shaped by key individuals, pivotal decisions, and a culture of open collaboration:

Paul Baran, Donald Davies, and Leonard Kleinrock independently invented packet switching — the foundation of all Internet communication
Vint Cerf and Bob Kahn designed TCP/IP — the universal protocol that connects everything
Tim Berners-Lee created the World Wide Web and gave it away for free
Kevin Ashton envisioned the Internet of Things — extending the Internet to physical objects
The Internet’s open standards culture (RFCs, free protocols, shared specifications) is why IoT protocols like MQTT, CoAP, and LoRaWAN are freely available today

The most remarkable aspect of this history is that the fundamental architecture designed in the 1970s — packet switching, layered protocols, end-to-end design — still works perfectly for IoT devices that are millions of times more numerous and diverse than anything the original designers imagined.

4.15 What’s Next

This section: What’s Next

Now that you can trace the Internet’s evolution from ARPANET to IoT, explore how these protocols work in modern systems:

Topic	Chapter	Description
Protocol Architecture	OSI and TCP/IP Models	Examine the formal layered architecture that grew from Cerf and Kahn’s TCP/IP design
IoT Messaging	MQTT Publish-Subscribe Basics	Explore how publish-subscribe messaging evolved from IBM’s 1999 protocol for IoT
Systems Evolution	Systems Evolution to IoT	Trace how computing economics and miniaturization enabled the IoT revolution
IoT History	IoT History and Paradigm Shifts	Identify lessons from technology adoption patterns across Internet eras
IPv6 and 6LoWPAN	IPv6 and 6LoWPAN	Describe how modern addressing and adaptation support constrained devices

4.16 Key Takeaway

This section: Key Takeaway — The history of the Internet shows why layered design, open protocols, interoperability, and fault tolerance matter.

The history of the Internet shows why layered design, open protocols, interoperability, and fault tolerance matter. IoT systems inherit those lessons when many vendors and networks must work together.

4.17 Continue Your Route

This section: Continue Your Route — This is the last part of this chapter.

This is the last part of this chapter. Return to Internet History: ARPANET and TCP/IP or continue from the fundamentals module index.

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