Internet Protocols: History & Versions

How the internet started

In 1969 the US Defense Department's ARPA connected four university computers in the ARPANET, the first large packet-switched network: data split into packets that find their own way, instead of a dedicated circuit per call. The first message, on 29 October 1969, was meant to be "LOGIN"; the system crashed after "LO".

In 1974 Vint Cerf and Bob Kahn published the design that became TCP/IP: one protocol to deliver packets between networks (IP) and one to make delivery reliable (TCP). On 1 January 1983, the ARPANET switched to TCP/IP in a "flag day", which is often called the birth of the internet. DNS followed the same year, replacing a single hand-maintained HOSTS.TXT file.

In 1989-1991 Tim Berners-Lee at CERN invented the World Wide Web: HTML, URLs and HTTP. Netscape added encryption with SSL in the mid-1990s, which became TLS.

Internet standards are published by the IETF as numbered RFCs ("Requests for Comments"). Anyone can join the working groups, and new RFCs replace old ones rather than editing them, which is why protocols have several RFC numbers over time.

Timeline of major protocol versions

1. HTTP/3Jun 2022Current

   • HTTP over QUIC (RFC 9114); the same year RFC 9110-9112 refreshed the HTTP/1.1 and core HTTP specifications
2. QUICMay 2021Current

   • A UDP-based, always-encrypted transport with independent streams and 1-RTT setup (RFC 9000)
3. TLS 1.3Aug 2018Current

   • One-round-trip handshake, only forward-secret key exchange, legacy ciphers removed (RFC 8446)
4. IPv6Jul 2017Current

   • RFC 8200 makes IPv6 a full Internet Standard (first specified as RFC 1883 in 1995 and RFC 2460 in 1998)
5. HTTP/2May 2015Supported

   • Binary framing, multiplexed streams and header compression, based on Google's SPDY (RFC 7540, now RFC 9113)
6. WebSocketDec 2011Published

   • Full-duplex messaging over one upgraded HTTP connection (RFC 6455)
7. TLS 1.2Aug 2008Supported

   • Authenticated encryption (AES-GCM) and SHA-256; still widely supported alongside 1.3 (RFC 5246)
8. BGP-4Jan 2006Current

   • The routing protocol between networks on the internet (RFC 4271; BGP-4 first appeared as RFC 1771 in 1995)
9. TLS 1.1Apr 2006End of life · Mar 2021

   • Deprecated with TLS 1.0 by RFC 8996 in 2021
10. TLS 1.0Jan 1999End of life · Mar 2021

    • SSL 3.0 standardised by the IETF under a new name (RFC 2246)
11. HTTP/1.1Jan 1997Supported

    • Persistent connections, the Host header and chunked transfer (RFC 2068, then 2616, now RFC 9112)
12. SSL 3.01996End of life · Jun 2015

    • Netscape's design that TLS grew out of; prohibited by RFC 7568 after the POODLE attack
13. HTTP/1.0May 1996Historic

    • Headers, status codes and content types (RFC 1945)
14. NATMay 1994Published

    • Network address translation to stretch IPv4 (RFC 1631)
15. CIDRSep 1993Published

    • Classless addressing like /22 replaced class A/B/C networks (RFC 1519, now RFC 4632)
16. HTTP/0.91991Historic

    • The first web protocol: GET /path and an HTML response, nothing else
17. DNSNov 1987Current

    • RFC 1034 and 1035, the core DNS specifications still in use (first designed in 1983)
18. TCP/IP flag dayJan 1983Historic

    • The ARPANET switches from NCP to TCP/IP
19. IPv4 and TCPSep 1981Current

    • RFC 791 and RFC 793 (TCP's specification was consolidated as RFC 9293 in 2022)
20. UDPAug 1980Current

    • The 8-byte-header datagram protocol (RFC 768), unchanged to this day
21. ARPANETOct 1969Historic

    • The first packet-switched network links UCLA, Stanford Research Institute, UC Santa Barbara and Utah

Modernisation turning points

• CIDR and NAT (1993-1994) stretched IPv4 for decades after it was clear that addresses would run out.
• HTTP/1.1 (1997) made connections persistent, so one TCP connection could carry many requests.
• TLS everywhere (2010s): free certificates from Let's Encrypt (2015) and browsers marking HTTP pages "Not secure" made HTTPS the default.
• HTTP/2 (2015) and HTTP/3 (2022) attacked latency: multiplexing, header compression, and finally a new transport, QUIC, built on UDP so it can evolve outside operating-system TCP stacks.
• IPv6 adoption grew slowly but steadily; a large share of traffic to major services now uses IPv6.

Version comparisons

What to use today

• TLS: offer TLS 1.3 and 1.2; disable SSL, TLS 1.0 and 1.1.
• HTTP: serve HTTP/2 and HTTP/3 at the edge (load balancer or CDN); HTTP/1.1 between proxies and apps is fine.
• IP: design new networks dual-stack (IPv4 and IPv6) where your cloud and tools allow it, and never overlap IPv4 ranges you might connect later.

Official resources

• IETF and the RFC Editor, where every internet standard is published
• RFC 9110: HTTP Semantics and RFC 9114: HTTP/3
• RFC 8446: TLS 1.3 and RFC 8996: deprecating TLS 1.0 and 1.1
• RFC 9293: TCP and RFC 8200: IPv6
• Internet Society: a brief history of the internet
• Google's IPv6 adoption statistics

Last reviewed 21 October 2026. Release and support dates come from the official release pages linked above.