Act 11969 · ARPANET

The internetgrew

First came the problem, then came the role.Follow the history of the internet to see how each role was born.

In 1969, the ARPANET, funded by the U.S. ARPA, connected its first 4 nodes: UCLA, the Stanford Research Institute (SRI), the University of California, Santa Barbara (UCSB), and the University of Utah. Each node was a machine called an Interface Message Processor (IMP).

On April 7 that year, Steve Crocker at UCLA wrote RFC 1, "Host Software" - the start of the "request for comments" tradition.

RFC 1 · Host Software

Act 21983 · TCP/IP

A network of
networks

On January 1, 1983, following the transition plan in RFC 801, the ARPANET switched completely from NCP to TCP/IP. From that day on, different networks could connect to one another through gateways.

That same year, the military portion split off from the ARPANET to become MILNET, and the two sides interconnected through gateways.

RFC 801 · Transition plan RFC 791 · IP RFC 793 · TCP

Act 31994 · the Web and China

China came
online

The ARPANET was retired in 1990, and NSFNET became the U.S. research backbone; commercial networks interconnected through exchange points, and the World Wide Web spread from CERN to the public.

On April 20, 1994, the NCFC project connected to the internet over a 64 kbps international leased line from Sprint in the United States, and China achieved full-function connectivity.

CAC · 30 years of full-function access CAS Network Information Center RFC 1630 · URI in WWW

Act 4Today · a layered network

Geography
disappeared

Today's internet looks more like a layered network: backbones and internet exchange points (IXPs) in the middle, a ring of public clouds, CDNs, and AI data centers around them, and countless phones, homes, and IoT devices at the outermost edge.

Networks exchange routes using BGP, and more and more traffic runs over QUIC, HTTP/3, and TLS 1.3.

RFC 4271 · BGP-4 RFC 9000 · QUIC RFC 9114 · HTTP/3 RFC 8446 · TLS 1.3

Act 1 nodes and links are real history · Acts 2–4 nodes are illustrative, not a real topology · hover or click a node for sources

THE TRUNK / Eras

Six eras, one trunk

Every era follows the same order: background and drivers → pain points → new technology.

Connection Era

Letting different computers and networks talk to each other

Web

Everyone can view web pages, and portals bring information online

Community & Search Era

Users start producing content; search and e-commerce find ways to make money

Mobile Era

The internet goes in your pocket; users and traffic explode

Cloud & Intelligence Era

A shift from grabbing users to running operations precisely with data and algorithms, while compliance tightened across the board

Large Model Era

Natural language became a new way to interact and to program

THE BRANCHES / Roles

The roles that grew from the trunk

Each role starts from a concrete problem and walks through a composite day in the job. Roles in gray have a place reserved; their content is coming soon.

THE THREAD / Throughout

Security and law run through every era

From the 1994 Regulations on the Security Protection of Computer Information Systems to today’s Personal Information Protection Law and Interim Measures for the Management of Generative AI Services, every era page has a “Security & law” section.