A Personalized History of Computer Communications 1950s -1970s and Beyond Mischa Schwartz Charles Batchelor Professor Emeritus of Electrical Engineering.

A Personalized History of Computer Communications1950s -1970s and Beyond

Mischa Schwartz

Charles Batchelor Professor Emeritus

of Electrical Engineering

Columbia University

New York, NY 10027

1950s, 1960s

• US Defense Activity- SAGE Network, 1950s, Radar Data NIKE Zeus Data Network, AT&T Bell Labs, circa 1960 Paul Baran, Rand Corp., early 1960s, Survivable Data Networks• Commercial Data Networking: Airlines, Banks, …• Computer Time sharing Project Mac, MIT (GE Corp.), early 1960s

Commercial Data Networking, 1950s, 1960s

• Airline Reservation Systems

American Airlines, LGA, 1952

American Airlines/IBM Sabre, 1959

IBM PARS, 1961

SITA, 1964

• Banking Networks

Ex: Lloyds Bank, UK, 1966 (IBM)

Airline Reservation Systems

• PARS, 1961 on

• SITA, 1964 on

Original PARS System

SITA Network

Banking Networks

Late 1960s to mid-1970s

• Private Data Networks-

Tymnet, GE Information Services Network

• Proprietary Computer Communication Architectures (Computer Manufacturers)

Ex: IBM SNA

• ARPA, ARPAnet

Private Data Networks, late 1960s-1970s

• Time-shared capability

• Terminal-oriented

• Data processing:

Interactive, Batch processing

Ex: GE Information Services Network

TYMNET (Tymshare, Inc.)

later- Networking functions

GE Information Services Network

Centralized Hosts

TYMNET

Distributed Hosts

Virtual Routing

Computer Manufacturers, late 1960s on

•Teleprocessing Networks-

Specialized Communication Controllers

• Proprietary Communication Architectures

Ex: IBM SNA (later DNA, BNA,…)

Specialized hardware, software

Layered architecture

IBM SNA

System Network Architecture:

Layered Architecture

ARPA, ARPAnet:Formative Years

• 1962, MIT: J.C.R. Licklider, “Globally interconnected computers” Len Kleinrock, doctoral dissertation (1964, “Communication Nets: stochastic message flow and delay”, McGraw-Hill)•1965, Larry Roberts, MIT Lincoln Lab, interconnected-computer expt. Donald Davies, British NPL, “packet” message vs. packet switching

ARPA, ARPAnet: Network Concept/Development

• 1967, Roberts, ARPA: “computer utility concept” BBN contract, IMPs• 1969, 4-node ARPAnet, datagram routing (1970, Host-to-Host protocol, NCP) Measurements- “incestuous” traffic!• 1974, Robert Kahn and Vint Cerf- TCP (1978-TCP/IP) 24 node-ARPAnet• 1976, 56 nodes

International Standardization Efforts

• Early 1970s, CCITT,

public data networking

• 1976, X.25

Datapac (Canada),

first public data network

• 1978-1980, ISO, OSI Reference Model:

7-layer communications architecture

X.25

Network-Interface Recommendation

OSI Reference Model

Seven-Layer Architecture

ARPAnet → Internet

• 1980-1983, TCP/IP adopted; replaces NCP

• 1985, 1986, NSFNET organized, regional nets encouraged: Ex: NYSERNET

• 1986-1995 NSFNET expands, commercial service

• 1995 on: full-fledged Internet!

Internet and Beyond

• Millions of Hosts!

• Multimedia traffic

• Wireless connectivity: 3G cellular data, 4G all packet-switched all-purpose cellphones 802.11 connections…

• Future? Your guess is as good as mine! But see following:

Focus on Personal Networks?

Example: (with due respect to Magda!)

MAGNET

(European vision) “My Personal Adaptive Global NET”