The Internet is, of course, a global packet
switched data network and the early history of its development
centres mainly on the evolotion of packet switching technology -
work on this subject happened independently in the UK and in USA
and there was also a certain degree of sharing of ideas...
In England, at the NPL (National
Physical Laboratory) Teddington site, Dr Donald
Davies conceived the idea of a "network" of inter-connected
data terminals where the data was broken into small chunks (or
"packets" as Davies named them) rather than in a continuous
stream, which also avoided the problem of short messages being
blocked behind long messages
Davies' ideas were first presented in public
in the USA at the ACM
symposium, in Gatlinburg in 1967, and in the UK at the IFIP
Congress, 1968, in Edinburgh
The NPL packet switching approach was adopted by the US Department
of Defense in 1967 and in 1968 aproject called the ARPANET, the
forerunner of the internet, was launched
The first ARPANET link was between the University of California
and Stanford Research Institute in 1969 and the first international ARPANET connection was made between
London and Norway in 1973
In the USA efforts to interconnect computers had been going on for
some time but had focussed on circuit switching rather than packet
switching
In 1959, a computer scientist, Paul Baran,
was working at the RAND
Corporation on the idea of interconnecting computers. In
1962, Baran presented a paper titled On
Distributed Communications Networks he proposed the computer
communication concept of standard message blocks routed as "hot
potatoes" in a store-and-forward system
In 1965, two computer scientists Dr.
Lawrence G. Roberts and Thomas Marill, conducted an
experiment to understand what it would take to interconnect two
computers, namely a TX-2 computer at MIT Lincoln Lab with a Q-32
computer at System Development Corporation in Santa Monica CA,
using a lease-line from Western Union - this experiment
highlighted the complexity of the problem and concluded that
circuit switching, as used by the telephone network, was a poor
solution
Roger
Scantlebury of NPL presented at the aforementioned
Gatlinburg conference in 1967 on the local
network being developed at NPL (National Physical
Laboratory) in the UK by Donald Davies, which used much
higher speed circuits - he also saw the US plans for
ARPANET and reported back "It would appear then that the ideas
in the NPL paper at the moment are more advanced than any
proposed in the USA"
Dr Roberts was heavily influenced by the NPL work, stating
later "The NPL paper clearly impacted the ARPANET in several ways.
The name "packet" was adopted, a much higher speed was selected
(50 Kilobit/second vs 2.4 Kilobit/second) for internode lines to
reduce delay and generally the NPL analysis helped confirm the
concept of packet switching
Here is a video of Larry Roberts
(Dr.
Lawrence G. Roberts) himself talking about much of the
history described above, including talking to Donald Davies of
NPL in the UK, about using the term "packets" and faster links
(at 11:10)
The key point about the approaches taken in both
England and America was that processing power almost dictated that
seperate computer systems were used to handle the establishment of
communcations between the main computers
In the video on the right,
Leonard Kleinrock, talks about what was first probably
the message sent on a computer network on Oct. 29th, 1969, between
UCLA and Stanford University
The word "login"
was typed but the system crashed and only "lo" was received
The first IMP had just been installed at UCLA in
Kleinrock's lab on that day in October 1969 and the first ARPANET
communication was established between with Douglas Engelbart's lab
at the Stanford Research Institute (SRI), as the commemorated by
the UCLA Office of Public Information below
By December 1969, the fledgling ARPANET had grown to
4 nodes, with the connection of the University of California at
Santa Barbara and the University of Utah
In 1972 the second phase of ARPANET
produced a major expansion from the 4 original sites to 40 sites
across the USA
In 1972 ARPA was renamed the DARPA (Defense Advanced Research
Projects Agency) in 1972 - there is an interesting section in RFC 1000,
which summarises RFCs 1 to 999, which starts:
The procurement of the ARPANET was initiated in the
summer of 1968 -- Remember Vietnam, flower children, etc?
There had been prior experiments at various ARPA sites to link
together computer systems, but this was the first version to
explore packet-switching on a grand scale. ("ARPA" didn't
become "DARPA" until 1972.)
In 1973 University
College of London in England and the Royal Radar Establishment
in Norway were connect to ARPANET
In 1975 satellite links to Hawaii and UK were added and there
were already 57 nodes in the network and the 1st of July
- That year the Defense
Communication Agency (DCA) took over direct control of
ARPANET, as there was risk to national security because of rapid
growth and complete lack of control over access and activity
In 1976 Queen Elizabeth II made
history by sending an email announcing that the Royal Signals
and Radar Establishment in Malvern was available on the
ARPANET
The video in the right, celebrating the 50th Anniversary of
ARPANET shows its evolution during the 1970s and the
interntetworking between various elements, which is also
covered below
Robert Kahn
of BBN also explains the network topology and resilience, with the
aid of diagrams drawn on a whiteboard - he is very probably the
industry's very first SE (Systems or Sales Engineer) - he goes on
to detail such familar topics as store & forward devices,
network management, remote admin and code upgrades
As Robert Kahn explains, the IMP
(Interface
Message Processors) used to form the ARPANET were
also suplemented by TIPs (Terminal Interface Processors), which
allowed connection of simpler terminals and were therfore early
terminal servers
Peter
T. Kirstein in England is often recognised as the father of
the European Internet as he was responsible for the first ARPANET
connected system outside of America
The British side of the story is remembered by members of the
original NPL (National Physical Laboratory) team in this video
The comparison with visiting ARPANET people from
America is mentioned and the connection of the NPL network with it
- most likely the first example of InterNetworking
Even an example of a data network carrying encoded
speech is explained - probably the first example of VOIP in the
1970s
This diagram of the ARPANET protocols shows a
multi-layered approach, much like the OSI 7 layer model and TCP/IP
5 layer model, which it obviously predates by many years, albeit
with only 3 layers
IMPs are interconnected at the first layer with
physical circuits and communicate via packets
Hosts are interconnected at the second layer with
virtual links and commicate via messages
Users processes are interconnected at the third
layer with virtual connections and communicate via byte streams
The ARPANET host-to-host communication used 1822 protocol, as
covered in the specification document on the left, along with
hardware and interfacing details
Data messages contained the destination host's address and the
data message being sent and the 1822 hardware interface allowed
the IMP to deliver the message to that destination address, either
to a locally connected host, or to a downstream IMP the last IMP
in the path transmitted a Ready for Next Message (RFNM)
acknowledgement to the sending host IMP.
Messages had a total length of 8159 bits, the first 96 bits were
reserved for the "leader", or header, and the remainder was data
1822 messages had guaranteed delivery and if a message did fail
to be delivered, the IMP sent to the originating host a message
informing it as such - this system proved not to be foolproof
though
Later versions of the 1822 protocol, such as 1822L, are described
in RFC 802 and
its successors
Stephen D.
Crocker, a graduate student at UCLA, created and led the
Network Working Group (NWG) and wrote the very first Network
Working Group Request for Comment
(RFC) which summaried the IMP Software, the Host-to-Host
Software and the Host Software - Click the image on the right for
the original copy
RFC 2 explained how to write RFCs and added that the Network
Working Group "seems to consist of Steve Carr of Utah, Jeff
Rulifson and Bill Duvall at SRI, and Steve Crocker and Gerard
Deloche at UCLA. Membership is not closed"
The problem with unreliable message delivery on the ARPANET was
addressed with the Network Control Program (NCP), which provided a
standard method to establish reliable, flow-controlled,
bidirectional communications links among different processes in
different host computers.
The NCP interface allowed application software to connect across
the ARPANET by implementing higher-level communication protocols,
an early example of the protocol layering concept later
incorporated in the OSI model
NCP was developed under the leadership of Stephen D.
Crocker, then a graduate student at UCLA. Crocker created
and led the Network
Working Group (NWG) which was made up of a collection of graduate
students at universities and research laboratories sponsored by
ARPA
to carry out the development of the ARPANET and the software for
the host computers that supported applications
RFC 384
lists all the OFFICIAL SITE IDENTS FOR ORGANIZATIONS IN THE ARPA
NETWORK in
August 1972- it only amounts to 4 pages
The ARPANET Completion Report on the right describes much of the
history covered above and also has more diagrams showing its growth
in the glossary at the end
In 1980 the whole ARPANET came to a complete halt because of a
message timestamp issue, which mimicked a DDoS attack - the details
were recorded in RFC
789 - at that time ARPANET had 213 hosts, with a new host
added approximately once every 20 days
The NCP protocol had some critical limitations:
Inability to address hosts and networks further downstream
than a destination IMP on the ARPANET
Lack of end-to-end host error control, meaning packet loss
causing protcol and and application crashes
Error control was never deemed necessary for the ARPANET as it was
designed as the only
network in existence
As changes in the ARPANET were ruled out, it was clear that new
protocol to replace NCP would be required - the new protocol would
need to operate more like a communications protocol, rather than a
device driver orientated approach that NCP took
In 1974 Vinton
Cerf and Bob
Kahn wrote the paper on the left detailing a new protocol
called TCP (Transmission Control Protocol), to correct all of the
shortcomings of NCP by itself
This early TCP implementation worked well with file transfer and
remote login but problems emerged with packet voice
experimentation in the 1970s, which showed that packet loss would
be better corrected by the application, outside of TCP
The answer was to split all of the functions of the original TCP
into two protocols and in 1978 TCP was split into:
A simple internetworking protocol to provide only packet
addressing and forwarding
An advanced protocol providing flow control and packet loss
recovery
These protocols, namely Internet Protocol (IP) andTransmission
Control Protocol (TCP) were combined into a protocol suite,
commonly known as TCP/IP for ARPANET
By 1983 the DCA (Defense Communication Agency) and DARPA had
made the historic move to establish these two new protocols as
de facto for the ARPANET - The Department of Defence (DoD)
also adopted TCP/IP and the paper on the right by Vint Cerf
and Edward Cain describes the implementation within the DoD
Peter
T. Kirstein was instrumental in defining and
implementing TCP/IP alongside Vint Cerf and Bob Kahn
Vint Cerf himself describes his
work and collaboration with all others invloved in this
video, including the TCP and TCP/IP protocols He also covers need for interworking, stemming from
the decision to allow seperate networks, with and
"Gateways"between them, which would later be renamed
"Routers"
This need for internetworking is illustrated well by the
diagram on the right, which shows how ARPANET and
MILNET, the part of the network that carried
unclassified United States Department of Defense
traffic, was physically separated in 1983.
The ARPANET served the academic research community
Gateways relayed
electronic mail between the two networks
Other direct connectivity between the networks
was disconnected
SATNET, or the Atlantic Packet Satellite Network as it was also
known, was an early satellite network that was
an important part of the first heterogeneous computer network
and the fledgling Internet
As the diagrams on the left and below show, SATNET was an
international link across the Atlantic Ocean to England and
mainland Europe, which used the Intelsat IV
and Intelsat
V geostationary communication satellite
Goonhilly, in Helston,
Cornwall provided the satellite link from the UK and, surprisingly,
a mobile van from Stanford Research Institute, as part of PRNET (Packet Radio
Network)
The SRI van looked much like a bread van but was actually a full
ARPANET node, equipped with a DEC LSI-11, packet radio kit, a
shielded generator and air conditioning
In 1976 on the 27th of August, the van was parked next to a
well-known Portola Valley, California biker bar called Rossotti's
(now the Alpine Inn),
with cables running to a picnic tables and it was then that first
two-network TCP/IP transmission was conducted between the van and
ARPANET
The first demonstration, linking SATNET, the ARPANET, and PRNET took place on
the 22nd of November 1977, when data flowed through the mobile SRI
van at Menlo Park, California and the University of Southern
California in Los Angeles via London, England, across three
different types of network: packet radio, satellite, and the
ARPANET, thus demonstarting the first Internet transmission between
three disparate networks.
From 1977 to 1978, the SRI van was also used for the first VOIP
(Voice over IP) tests, using ARPA's Network Speech Compression
Program, over the Mickey Mouse phone in the van
The video on the left Robert Kahn talks about various parts of
ARPANET, including IMPs, packet radio and the invention of
gateways, which eventually became "routers" in the Internet
The report on the left details testing conducted on SATNET in 1988
for TCP throughput perfomance, round trip, packet loss etc. as well
as its structure
as standard Domain
Name System or DNS is introduced to identify the type of
institution which represents the host
The various application protocols such as TELNET for remote
time-sharing access, File Transfer Protocol (FTP) and rudimentary
electronic mail protocols were
developed and eventually ported to run over the TCP/IP protocol
suite or replaced in the case of email by the Simple Mail
Transport
Protocol.
In the same year the
Domain Name Server (DNS) was developed at the University of
Wisconsin. This allowed users to refer to sites by name and became
the largest distributed database ever. By the following year DNS
was introduced to the network and it had over 1000 hosts � small
by today�s standards.
1970 – ARPANET started using Network
Control Protocol
1972 – Telnet was implemented
1973 – FTP was introduced
1974 – TCP was specified
1981 – IP was specified
1983 – ARPANET changed to TCP/IP
1984 – DNS was introduced
1984: EGP
1988Internet Relay Chat (IRC) is
developed by Jarkko Oikarinen.
1989 – 1991: BGP-1, 2 and 3
1994: BGP-4
1991WAIS, invented by Brewster
Kahle, is released by Thinking Machines Corporation.Gopher is introduced by Paul
Lindner and Mark P. McCahill from the University of Minnesota.
1993 – WWW invented
World-Wide
Web (WWW) is released by CERN in Geneva, Switzerland.British researcher, Tim
Berner-Lee creates HTMLThe web as we know it is born!
Sorry but there's only pictures to look
at here so far - I'll add some words when I get time!!
Until then though, this TCP/IP
Bible may prove useful! - Here's some more detailed info on
OSPF and BGP .....
plus a Design Guide
for large IP networks (covering OSPF & BGP)
In 1968 Dr Roberts
beame the program manager for ARPANET and Wesley
Clark suggested the use of dedicated computers in a message
switching network, which were later called Interface
Message Processors (IMPs) 
