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Good evening
Good evening ladies and gentlemen...
(the microphone is on)
Thanks very much for coming on a Monday night to celebrate
the UK's computing heritage. It's fantastic to see
so many of you here and so many
faces that we
recognize
So as you know the UK has a fabulous and long
computing heritage
but it's not something that has necessarily reached a wider audience
in recent years, it's kind of a hidden secret very often
and this is something that we at Google have spent
some time
quietly trying to encourage more knowledge about the UK's
computing heritage over the last
two or three years, so we're delighted to have you here tonight
to meet some of the pioneers of the Internet...
Thank you for not saying dinosaurs!
To look at some some films that we've been producing over the
last couple of years
and to hear some some talk so
the evening is in a couple of parts, we're going to talk here
to the four musketeers of the Internet in a moment
Then we'll have a little bit of break, an opportunity to mingle some more
eat some sweets and popcorn
and then we're going to come back with a couple films a couple of talks and a Q&A with Vint at the end
of the evening
right
so I'm going to sit down and we'll kick off
So let me introduce you to four
of the great pioneers of the internet, starting on the
extreme left there, Peter Wilkinson and Roger Scantlebury who were at
NPL back in the 1960's and 70's
and really helped develop I suppose what you could call
the first Internet like thing
in the UK and indeed in the world
and certainly the term packet switching
developed, or coined for the first time at NPL in
the 60's
Vint Cerf
now obviously at Google, Chief Internet Evangelist
at Google and Google glass wearer
That would be me!
who was at Arpanet at Stanford again back in the 60's and 70's
actually at UCLA it was Arpanet
Internet is Stanford, you know the difference between Stanford and UCLA
we'll get to that.... is there a difference? we'll come to that
and DARPA as well
and Peter Kirstein
University of London and the first person to bring the Arpanet node
to University of London in the early 1970's I hope I made that
introduction reasonably accurately
So really, my role in this is not to intervene too much but really
to wind them up and and let them go and having had a little bit of a conversation
with them earlier, I don't think that's going to be too much of a problem
So Roger, I was going to kick off with you... If you don't mind I'd like to grab a hold of this...
he always does! ... it's habit, sheer habit!
so um... Peter and Roger were both at the National Physical Laboratory and the
then superintendent of the computer science division
was Donald Davies
who was instrumental in inventing the term packet, he worked with a linguist to do that
but what was more important is that he initiated a project there
to build what was intended to be a national scale packet switched network
so the documentation, the design work and everything else all of which took place
during the mid 1960's and to the late 60's
and early 70s
It was intended to be a project not at all unlike the Arpanet project which began
in 1968 so I mean, they were
essentially contemporary
projects each of them intended to be a small-scale network to test the
idea of doing store and forward packet switching
so Roger and Peter were very very much a part of that early design work
and in fact I'll let you guys tell part of that story ...
Roger brought... was the first person to bring some of these ideas from the UK
to the US in 1967 at a conference in Gatlinburg
Tennessee where he met with
Larry Roberts who was the primary overall manager of the Arpanet
project for the defense department, so can you give us a sense for how this
thing actually got started... in fact what the hell was NPL doing
in communications when that wasn't your charter
well that is true, and of course we got
rapped over the knuckles for doing it but hey, what the hell you know
Perhaps it would
be a good idea to put it in context
Donald Davies as you said was the superintendent of the computer science
division
and our computer science division had had a long history in computing
going back in fact to Alan Turing
who came to NPL in 1946 I think
and in fact I've got a picture of the Colossus machine... there's Alan Turing
he was responsible, well not responsible solely but was one of the prime movers and
shakers in the
Bletchley Park
machine, the Colossus... Shall we pause for a moment, how many people have had an
opportunity to go to the computer history museum in Bletchley Park?
a few...
quite a few... Good OK... So you guys will have seen this machine
actually still operating
which is a remarkable feat
As I say, Turing came to NPL in '46
to start work on a computing project
we were going to build a thing called the ACE
computer
after about a year he got fed up with the prevarications of the civil service
who operated the national physical laboratory and decided to go and work
with Max Newman at Manchester on the Manchester Mark 1
fortunately for us he left behind a dedicated team
one of whom was Donald Davies
who was his
sort of immediate aide
and some others like Ted Newman and the mathematician Jim Wilkinson
not me, no, no relation!
and several other noteworthy people
and they built
a pilot model of the ACE, they decided to do a cut down version first and this is
a picture of the
pilot model ACE which I think is actually in the Science Museum now...
...but not functional is that correct? I don't think it's functional ...
[no it's in the Alan Turing exhibition]
okay
that machine first ran serious programs in 1950
and there's a bit more to it than actually shown in that photograph
there was some..
the short term memory, the RAM
was mercury delay lines, sonic mercury delay lines
if somebody had walked into my office and told me they were going to build a memory system
based on
sonic
transmission in a mercury delay line I would have thrown them out of the office
this is nuts, how could that possibly ... strangely enough it worked
they were kept in a special heat constrained room
because the mercury would change length with temperature..
and then we had some drums to the machine
for my sins I joined this team in 1955 would you believe
and worked a little bit on this machine but on its commercial successor
which was the
the Deuce computer, I think we have a picture of the Deuce
[there we are, that was it]
and here we see hardware and software
... oh this is Deuce because the first one was ACE and the second... oh boy
oh yes, minus two!
yes so the software is in the
punch card box here in the ... just in case there are any misunderstanding here
that was a commercial machine, I think there were about thirty-odd of those
machines actually sold in the UK so it was quite a successful
machine... thermionic
tubes of course
... So ACE was tubes also?
ACE was tubes and the follow-on to that, the thing that
was called the full-scale ACE was also tubes
there were tubes for another ten years
the 1794 of that era was the first one which
was semiconducting
but that's the background of computing in NPL
and then in the early 1960's
Donald Davies had become aware that
the next big thing was going to be the communications
between computers
and had
fairly quickly come to the conclusion that the telephone network was
not the right vehicle for connecting computers together
we had a meeting
with the Post Office research people in Dollis Hill
I seem to remember in the early 1950's
ah, early 1960's I'm sorry
and they
the chairman was an erstwhile
analog
switched telephone network man, he had been chairman of the CCITT
and he just gently pointed out to us that
digital telephony was really nowhere
there were millions of telephone handsets and about two thousand modems
in existence, so clearly
it wasn't going to go anywhere and we should
stop messing about... and stop wasting time
go away and do some thermometers or something or whatever NPL was supposed to do
So Donald, of course once he became superintendent had a budget
and was able to
... I think it's called Black Ops
well, some of us in the US we call these skunkworks
because no-one wants to go there because it
smells bad
and they stay away and you get some work done
and that's where we started the work on the
NPL proposal for a national network
quite rightly so
...and that work started in 65 and we published a report
in 1967 which I had the privilege of
taking to Gatlinburg where I met Larry Roberts for the first time
and the rest as they say is
history ... History or disagreed history
as one who tried to write a paper on that, and then had to
try to make peace I'm not sure
it's all history
well one question i have for Mr Wilkinson is what was your role..
in fact, for the two of you what was your role in the project itself, the network project
I was a sort of software guy
you were the software guy, OK
I'd been a part of the team working on the feasibility study
and it came to the point where we decided we were going to build our own local area network
within the NPL campus
so the finger pointed at me
Wilkinson you'll write the network software won't you
so I said fine, ok, yes
I'd expected to be asked
but I really didn't have a clue where I was going to start
so what computer did you use to build the packet switch at NPL?
We chose the same computer as it happened that the Arpa people had chosen
DDP-516
doesn't tell you a lot, does it really
this is a complete coincidence right, because the Arpanet used the
DDP-516 machines from Honeywell also
instead of the Plessey machine
We'd originally chosen the machine
the Plessey
XL 12 machine
to do this role, and the reason we chose it was because it had a digital
direct memory access system
and you could attach 500 devices to the
DMA channel
which meant you could input and output to devices without interrupting
sorry, without running
through the processer, so the processer merely had to do
buffer allocation and
that sort of stuff... And it also had a good interrupt system
which was pretty crucial I think
It would turn out that the ..
DDP-516 was similar
almost as good
architecturally
and the Honeywell team were extremely collaborative and cooperative
and would do what we wanted to
bring it up to our requirements... If they actually built a ...
we slipped them the idea of this DMA channel and they built it for us
so within about, I think it was less than a year, about 9 months from the time we
learned that we weren't allowed to buy the XL 12 because
somebody in the Ministry had decided that Plessey didn't make computers
they were just told, sorry you don't make computers
and so we got the DDP-516 team to build the
direct memory
input output
and if you go back to that picture
on this side you'll see all the digital equipment, the input-output
mechanism and the multiplexes and the line drivers that fanned out all
over the
the lab
The National Physical Laboratory
covered an area of 78 acres and there were..
ultimately we had several hundred terminals and computers attached to the network
and they would all run through this digital network
and in fact it was
like a modern local area network... it ran at 1 megabit per second
it was a 1 node network although the design was intended for multiple nodes
but the idea was that this would be a packet switch
and it indeed was a packet switch
and we weren't allowed to build a wide area network
because we were forbidden, so we just built the local area network
because they couldn't stop us... so what's interesting is they used a T1 speed system
a megabits based system
in order to connect the devices to this switch and it would have connected the
switches to each other
In fact I'd like to comment on that particularly
there were some other
very significant differences
in the thinking behind the NPL network
and the thinking behind the Arpanet
one of the problems which Arpa had at that time
was that they were not in the. they have to
they had to connect computers together
and Steve Lukasik as director of DARPA
spent many many anxious months
trying to prepare papers to prove he wasn't in communications...
because if it was the defence communications agency would have taken
over the project
all he was doing was connecting computers
by contrast
NPL started ... at least Donald started from the other side
he said, look
whatever the british might be saying about analog switching
and one must remember that in around about '61 '62 one had the
first digital telephone switches
they didn't work very well was one problem, but much more important
because of
something which may sound familiar to you, because of problems with unemployment
one decided to stay in analog switches for another ten years because the
analog switches were built in Liverpool and Nottingham
and shelve digital switches
Donald however said look
the T1
well, depending on where you are whether it was 2.048...
it was 2.048 as far as the British were concerned, a T1
that is the future of communications whatever the British post office
and DTI might say, therefore
we should build this lowest level
of switching
into
the same communication infrastructure
that was a thinking which actually didn't occur in the US until quite a few
decades later... that's true, that's true
even though I'm of course a great believer in
what you were doing of course... so this actually is a very interesting
observation because the T1 notion arose in the telecommunications
world more or less in the same period of time in the early 1960s
and yet by the time DARPA was doing the Arpanet project
it took convincing by Roger at this meeting in Gatlinburg
to recommend that the Arpanet project which is intended to be a wide area
four node network initially and then it would grow if it worked
they were looking at 2.4 kilobit
circuits using relatively low speed modems, at the time 2.4 kilobits
was thought to be a moderate speed
and Roger quite correctly pointed out and partly on behalf of Donald Davies that
a much higher speed would reduce the delay for forwarding the packets through
the store and forward network
that convinced Larry to go to 50 kilobits a second
but what puzzles me and i hadn't thought about it till now is that the T1 was actually
functionally inside the network but it would not occur to the telephone network
people
to externalise access to the T1, that was their trunk speed
what the hell do you think you're doing connecting
your peripheral device at our trunk speed, you'd overwhelm the trunks in
no time at all
so we ended up with
bonding 12 analog voice channels together
to make 50 kilobits per second with a
Bell 303 A modem that was half the size of a refrigerator
but we chose the same DDP-516 computers
completely independent of each other
and built the Arpanet in 1968... you are aware that
the guys from Bolt Beranek and Newman actually came over to NPL
in I think, '68
for a kind of a...
we had exactly the same problems you know, we weren't allowed by the
record carriers to do wide area networks we solved it one way
the Arpa people
called it something else and solved it another way
but a lot of that thinking was discussed ... that's interesting, I didn't know ...
now the T1 carrier of course was invented as a way
of multiplexing lots of speech channels
over a pair of wires because they were running out of duct space in the ground
and so to
take a whole T1 carrier when you can actually multiplex 24 or 32
speech channels
as you say, what are you doing, you know you can't do that, well actually you can
so you were running 25 times faster than we were
in the backbone
but our problem was to build a wide area network you had to get channels that
would go over a wide area and they refused to offer us anything more
than 50 kilobits a second
so now Peter Kirstein
in 1973 receives the first
Arpanet node in the UK
connected at the time to the Norwegian
defence research establishment
by way of a 9.6 kilobit landline... I think I'd go back a little bit further
first of all
the one which was supposed to go
onto Arpanet
was the NPL
what actually happened
was that
DARPA which
i think that at stage it was ARPA, the advanced research projects agency
was very advanced
technically
but completely and absolutely naive
at what communications... international communications was about
unsophisticated would be the best way of saying it
they're a bunch of geeks right, they didn't know anything about telecom policy
and any of you who have any idea of geography
would understand why
one might have three
large seismic arrays
in Norway
Montana
and Alaska
it's purely arbitary of course where they were politically placed
pointing somewhere... but they did happen to have three seismic arrays
remember this is in the days of the limited test ban treaty
and the question was had the Russians exceeded
the limits of the test ban treaty, how could we tell... they wouldn't let us
colocate with their test so we had to detect what they had done using the
seismic array system
and Norway was a convenient location... and that there was a treaty
at very high-level organised between parliament and congress
on collaboration
on this seismic array business
well, although on the whole
we regard things the packet switching, as far as
Arpa was concerned one of the very very important uses of this peculiar thing
they were building
was actually
to connect
things like these seismic arrays
back... and that was computer connection after all
back into some big data stores
which they were building in Washington
so somewhere around 1969 1970
when
Arpanet was just starting
Larry Robers had the mission
of putting this seismic array
onto the Arpanet
and put it in with a 2.4 kilobit line
well, by that time
modems
they were very expensive
but you could just about go up to 9.6 kilobits
shocking... this was possible
and so obviously in those days there were almost no earth stations
one of the very few places which had an earth station
was Goonhilly
and so the only way you could connect
a norwegian earth station
was to take
a satellite connection
to Goonhilly
go by landline
to London
go by undersea cable
to Norway
and that way you put the seismic array on
well I did start by saying
that Larry was a little simple-minded in some things
he thought well you just cut the line, it's already going to London
just have it go to the NPL connect them onto the Arpanet too
and then go on
but there were
two of three problems
there were some minor problems about communications but I'll forget those because
I have to solve those two
what was rather more serious
was that five years earlier
Mon Général
General De Gaulle
had said no
non
to the british joining the common market
this may sound familiar too
but that's beside the point ...
he had said no
and so at this stage
when it was suggested
that the NPL
go on to
the Arpanet
at the highest and I mean the highest level of government
the british government said non orno
because
america was bad
USA was bad, europe was good
therefore... we've come full circle haven't we!... well I didn't like to say that!
our papers say the same sort of thing!... but therefore Donald was
not allowed to connect it on
well I was definitely second best
but I had
had a certain awareness of the US and various things at the time
so he gave me
the largest amount
that he was able to
do from his own budget
because as soon as he went outside his own budget there'd be minor
political problems which would become bigger political problems which have become
another no
and so he offered me five thousand pounds
to connect... that was when five thousand pounds was actually worth something
you could buy a whole computer for that
well, you couldn't, no, computers were expensive too
so he offered me five thousand pounds
and I would put in a proposal to the national research...
to the science research council
that
with this offer from Larry Roberts
so that went in
but nobody in the government believed this kind offer from Arpa
and the next that happened
was a telegram went
this was the days when telegrams were existing
and the telegram went
from the director
of the research council
to the director
of DARPA
requesting
confirmation of this offer
this was the first
the director of DARPA
had heard of a ...
an international connection to a rather sensitive...
not classified but sensitive
installation inside
funded by ARPA.... To make it even worse, you want to connect
a college academic thing
to our seismic array in Norway, are you crazy?
it was worse than that
I also wanted to find information
about how a defense line
LO 51 was connected
to the US from Norway through Britain
and those days
academics were not allowed to know anything about
defense lines
didn't we run into a problem with the fact that you were a civilian
university and Arpa was a US defense activity
and the seismic array was a defense activity, and how can you connect
a military thing to a civilian thing... oh it got a lot worse than that
if you look at this picture behind you
eventually when we were
I can't remember how we actually worked the Oracle, I think you were a great deal to do with
this Peter, but we actually managed to connect the NPL network through UCL
to the Arpa network, and at the same time of course
there was a thing called the European informatics network
and NPL was the UK node on the european informatics network
which was also connected to the french research network the Cyclades network
and all of a sudden the post office and Cable and Wireless and AT&T
became suddenly extremely scared that there was a big scale
international network
and all hell was let loose
we had to sign
disclaimers this long about what we were and were not allowed to
do through this connection... so I want to take advantage
of this part of the discussion to point out to you that if you think
that computer networking is mostly about technology
you're wrong. It's mostly about trying to solve bureaucratic problems
and getting people to cooperate with each other. The policy problems are
harder than the technical ones...
well one of the fellows who was in charge at that stage
of post office policy
was somebody who you may remember, George Orchard
and I was having lunch with him one time
and of course
in those days
the post office had a complete monopoly
on message switching
and if you think message switching is something electronic, you're wrong
if you do a semaphore
across a public right of way
that was probably message switching
...optical!...
and things like
emails had sort of been heard of
and were clearly and strictly completely illegal
so i put a problem
it was illegal
if you were connected to the telephone
so I put a little problem to George
I said George
I have a computer
and my computer
has files
and for
59 minutes
well for 50 minutes I said first
in each hour
it's connected to telephone
and during that time
people put their data
into my files
then I disconnect
the telephone network
and do a little bit of sorting of the files
and then I connect
onto the telephone network again
where have I done something wrong
and when he had little difficulty with that, well what happens if I change it to
59 minutes and one minute
or 59 minutes
and 59 seconds and one second
where was the illegality
and I'm afraid his answer was oh Peter I wish you hadn't asked me that question
so what what's your... one thing i would like to suggest now and I don't know how
your timing is... I think we've got about five minutes, oh 10 minutes
ok so another thing, if we could have that little diagram back again for
a moment
this doesn't
show
the NDRE component which would have gone up from UCL... It wasn't significant
sorry?... It was not significant
it was also part of a military system... what do you mean by it wasn't significant?
what I mean by that, there was a very very
important difference
between what the norwegians did
and what the british were doing
the norwegian ... no part of NDRE
the norwegian defence research establishment was attached
only the seismic array
... there was no onward links from the large computer in Kjeller
it was attached by itself
and there were no links beyond it
by contrast
from the beginning
the british
we had several networks
and if I may just say one more thing about that
one of the biggest networks on it at the time
was the Hindley Physics network
and that
included of course
a link onto CERN
and so of course I got a question from the beginning from CERN
I had to ask for permission from anybody who was on it
could they
link in
to the Arpanet
so of course I had to ask my committee which included
the British post office, could they
and the answer was of course no
but then they went on to say
but how are you preventing it
so I sent back a long answer
there are the following six methods
in which they could get on
the following five I can prevent in the following way
but the sixth, I could put up a notice
if you do A B C D and E
you would get onto the Arpanet but that's illegal
shall I put up that notice?
the answer was, no I shouldn't! so you can see, we weren't always popular
the attitude actually at the Post Office office was
we were completely harmless
so let us do what we like
and watch us
and unlike these dangerous people like the National Physical Laboratory
who would of course move the country we would do absolutely nothing which was of any risk
to anybody
so now I think I'd like to pick up the trace here in a couple of ways
First of all, when the first node of the Arpanet was installed at your facility at university college london
the first european not just the first ... the first european node
the first node of the Arpanet was installed at UCLA in fact
in 1969 but it's 1973
and this node is connected
I think the way it worked was there was a satellite link that went from the east
coast of the US internal to the Arpanet dropping down to an imp
at Norsar in norway kjeller
and then a landline from there went to UCL
but we were interested in experimenting with packet satellite
in addition to
dedicated landline packet switching
so not long thereafter
a packet satellite effort was put into operation using Eutelsat 4A
over the Atlantic
then it linked the eastern coast of the US with the west coast of europe
and the idea was to have multiple nodes in the packet satellite system sharing a
common satellite channel, it was like an ethernet in the sky
it had a bandwidth of
64 kilobits a second.. so these guys are still blasting along
at a megabit and a half or 2 megabits
and we're still farting along, you know
at our little tens of kilobits a second
eventually I think we doubled that
to 128 kilobits but the concept was actually pretty interesting
because these multiple nodes
would share a common satellite channel
it was a multi destination half duplex system
and I remember when we ordered
we put out a bid
for a multi destination half duplex satellite system
and we got back a number of bids and one from western union international
read you know, dear DARPA we are delighted to provide you with a
multi destination half duplex system, by the way what is it
so we designed and built under DARPA for sponsorship this
dynamic packet satellite system
and eventually
Peter's system
was cut off
from the internal Arpanet and forced to operate solely over the packet satellite network
in the meantime
in the united states we were experimenting with mobile packet radio
which is what you carry around in your pockets these days
at the time it required a cubic foot packet radio system that cost
fifty thousand dollars per radio
they were operating at a
hundred to four hundred kilobits a second
in the 1710 to 1850 radio band and they were using in that system
spread spectrum
CDMA
now this is in the early 1970's so it was a very very advanced system for its time
but the part I wanted to get to is that we've got these three networks now plus
the ones that you see here
all interconnected over satellite link and the packet radio
system and the Arpanet
Peter's job at UCL was to implement the internet protocols
so his team was part of the
first three groups
that implemented TCP/IP starting in 1975 the other one was
at Bolt Beranek and Newman
and the third one was in my lab at stanford university
so we were doing tests
at the blinding speed of three packets per second
over this multi
network
system
we were also experimenting
with packet voice and with packet video, video a little bit later in the late 70's
voice in the mid 1970s
this is the part that I wanted to
take advantage of because we were testing packet voice
and with a fifty kilobit backbone in the Arpanet you couldn't put a
64 kilobit voice channel through there very well
so we used linear predictive code with 10 parameters as a way of
compressing the speech from sixty four kilobits down to
1800 bits per second
what you do is you send the ten parameters that represent the diameter of
a stacked array of cylinders that are changing
as the voice is speaking and then you excite that with a Formant frequency and you just
send those eleven things
forwarded over to the other side and they undo
the compression
and produce sound
well you lose a certain amount of quality when you go from
64 kilobits to 1800 bits per second
and the way it sounded when it came out the other end was like a drunken norwegian
so I'm at DARPA by this time and it's now time to demonstrate the packet
voice system to the guys at DCA, the defence communications agency who are
you know all about circuit switching and everything
so I wonder how was I going to do this and I remember thinking well wait a minute
the norwegian defence research establishment was part of the test
so we got Ingvar Lund to be the speaker
first we had him speak through the ordinary switch voice system called Audobon
then we had him speak through our packet voice system and it sounded exactly the same
so we didn't tell the generals that everybody would sound this way
as they went through this system
so these guys, NPL, UCL and these personally
and their colleagues were very much involved in the earliest
stages of both packet switching and international networking
and interneting
in the mid 1970's and that story is not very widely appreciated
here in the UK. Do you remember there was a paper that
you, Alex Mackenzie from Bolt Barenak and Newman
Hubert Zimmerman from the Cyclades network and I was the fourth author
and it was an inter-network protocol that was a proposal
we were trying to show that something that was TCP/IP eventually
was something that you would use between the systems at the end
of this
conglomeration of networks none of which was the same inside
none of which had the same interface
but which could be connected together... interoperability was everything
and Cyclades, I'm glad that we have this up here as well because
the French had their network which I think Segal was the packet switched network
and Cyclades was the larger scale system with the host computers in it
what's important i think is that the Internet project was informed
very much by its interactions with people outside the united states so we
when you keep hearing that
the internet was an american invention and everything else that's not exactly
correct because Bob Kahn and i
spent a lot of time
with our colleagues here and on the continent
exploring this stuff, and I'm just getting the shut up now signal so I'll shut up now
So we've got up to the mid 1970's but I'm afraid we're going to have to stop it there
but thank you very much indeed gentleman we had the rolling stones at the
weekend and that was great but I think actually this was the gig to be at
tonight and I think our gentlemen are
... doing rather better than the the rolling stones in terms of
remembering it all and giving it afresh
so we've run a tiny little bit over, what i suggest is that we give
our panellists a big round of applause...