"We had the great advantage of getting paid to do this full-time for a living," Shoch recalled. "The ARPANET guys were working under government funding and university contracts. They had contract administrators
and students working for them and all that slow, lugubrious behavior to
contend with. We had a lot of resources and a lot of machines and we
didn't have much else going on. We were evolving ahead."
*It would be several years before overall activity on the ARPANET significantly surpassed what PARC generated within its own building. As late as 1979 the average daily
traffic on the PARC Ethernet, which linked 120 Altos and Dorados, came to fully half
what was carried nationwide on the entire ARPANET.
But when
ARPA
invited them to
a technical
meeting to work out the
very
same issues they had already
solved, they
faced a painful dilemma.
Xerox's
lawyers, still deliberating whether
to
patent Ethernet or market it
as
a
proprietary product, placed the
PARC team
on a short leash.
"We
were
told to participate in the meetings," Shoch said.
"But we
were
ordered
not
to describe what we were
doing."
Nevertheless,
they felt a powerful
urge to impart
their wisdom to their
friends at
ARPA.
Thanks to the legal
beagles'
strictures, they
were
reduced to
getting their points across
by a
weird pantomime of asking
inscrutable
but
cunningly pointed
questions.
"Somebody would be talk
ing
about the design for some element
and
we'd drop all these hints,"
Shoch
recalled. "We'd say, 'You know,
that's
interesting, but what hap
pens
if this error message comes back,
and
what happens if that's fol
lowed
by
a
delayed duplicate that was
slowed
down in its response from
a distant
gateway when the flow control
wouldn't
take it but it worked its
way
back and got here late? What do
you do
then?' There would be this
pause and they'd say, You've
tried
this!'
And
we'd reply,
'Hey, we never
said
that!'"
Eventually they managed to communicate enough of
Pup's
architec
ture
for it
to
become a crucial part of the
ARPANET
standard known as
TCP/IP,
which to this date is what enables data packets to pass gracefully
across the global data network known
as
the Internet—with a capital
"I."
PARC's
contribution is mostly unsung; one recent history of the Internet
acknowledges only that
PUP
"inspired"
TCP/IP.
Metcalfe,
Shoch,
and
the others have gotten used to their contribution being minimized
unfairly. "The
TCP/IP
guys will never tell you they did this because of
Xerox,
because they don't remember
it
that way," Shoch said.
"But
we
would sit there explaining the problems and trying to coach them along.
We
had all this shit up and running, and
we
couldn't tell
them."
Despite the lawyers' strictures on cooperating with
ARPA
and others
on the outside, Shoch figured he should be allowed to play in his own
sandbox.
What
was the point of having access to the
Ethernet
if you
could not even use it to finish a paltry doctorate?
He
carefully assembled a stack of provisional clearances and approvals and made sure the
Xerox bureaucracy knew that more was at stake for him than a ten-
page paper in a scientific journal. Finally confident that he would be
able to publish what he learned, he set out to pound on the Ethernet
like a kid beating a drum.
To begin with, he wrote a program that would spew message bits
onto the Ethernet for a ten-minute period without interruption, starting at the stroke of midnight. He and a colleague named Jon Hupp
spent hours laboriously loading the software into 100 idle Altos after
dark, when the rest of the lab had gone home. Then they waited for
12:10
a.m
. and repeated the circuit, this time collecting each machines
data on how many of its packets got through to their destination, compared to how many got tied up in the system by gridlock. Before this
ordeal had run its course, Shoch realized he had committed himself
and his friend to the dreariest and stupidest exercise known to man.
Doctorate or not, he was damned if he was going to go through that
again. Somehow he had to figure out how to make the machines do the
bleak scutwork. It should not be an insurmountable task, he figured—
just a simple matter of getting the machines to tell him they were idle,
then distributing by Ethernet the very same program that he had
hauled around to a hundred offices on that first night. In principle this
was not much different from booting up or sending files over the net,
something that happened at PARC dozens of times a day.
Within a few days Shoch had written a new program that would
instruct one Alto to ask the others if they were free. The only complication was that unoccupied Altos at PARC were never entirely idle. After
their owners departed they remained on, spending the night running a
diagnostic program that continually tested the memory chips
—
those old
buggy Intel 1103s—for incipient failures. The test program, which
kicked in automatically whenever the machine remained inactive for a
certain number of minutes (just like todays automatic screen savers),
would prevent the Altos from responding affirmatively to his query.
Shoch strolled down the hall to David Boggs, who had written the
diagnostic. "Could you just add this thing to the program so the
machine will answer mine and tell me he's free?" he asked.
Boggs
shrugged. Helping a colleague like
this was
coin of the
realm
at PARC. "No
problem," he
said.
"I can do
that."
"And
while you're at it, can
you
make
sure that
if
I
send him this land
of packet he'll reboot with my software?"
"I
can do that."
"So all of a sudden," Shoch recalled later,
"you
could send out a 'Hello'
to any free machine and say,
'I'm
going
to
load this program on you
through the net, and when
I
say
"Go"
you're
to
start generating bits onto
the network. Then I'm going to
poll
you
all remotely
one by one and take
back all the data and make a printout. And
then
I'm going to produce this
chart
and get my Ph.D.'
"
Inducing fifty or a hundred
Altos
to
answer
a summons dispatched
by the press of a button gave
him
a
giddy feeling
of power.
"It
was like
sitting at the helm of the Starship
Enterprise,"
he said, "in control."
Perhaps
that was why his thoughts soon
turned
from communicating
directly with each machine to instructing them to talk to each other.
What if, rather than loading the same program onto fifty machines from
one central point, he gave each
one
the
ability
to seek out the others?
"Instead of my having to find
fifty machines,
maybe
I
just find two, and
tell
each of them to find fifty
more. Then each
of
those
machines is told
to
find twenty-five more." And
on
and
on
—
the
possibilities were infinite.
"It's
the kind of thing you think
about late at
night," he laughed—
but
it
was not the first time something
of
the
sort had
occurred to the human
mind.
As
he explained the concept one
day to
a group of colleagues, he
was interrupted by a Stanford
intern named Steve
Weyer.