<s>
The	O
Cambridge	B-General_Concept
Ring	I-General_Concept
was	O
an	O
experimental	O
local	B-General_Concept
area	I-General_Concept
network	I-General_Concept
architecture	O
developed	O
at	O
the	O
Computer	O
Laboratory	O
,	O
University	O
of	O
Cambridge	O
starting	O
in	O
1974	O
and	O
continuing	O
into	O
the	O
1980s	O
.	O
</s>
<s>
It	O
was	O
a	O
ring	B-Architecture
network	I-Architecture
with	O
a	O
theoretical	O
limit	O
of	O
255	O
nodes	O
(	O
though	O
such	O
a	O
large	O
number	O
would	O
have	O
badly	O
affected	O
performance	O
)	O
,	O
around	O
which	O
cycled	O
a	O
fixed	O
number	O
of	O
packets	B-Protocol
.	O
</s>
<s>
Free	O
packets	B-Protocol
would	O
be	O
"	O
loaded	O
"	O
with	O
data	O
by	O
a	O
machine	O
wishing	O
to	O
send	O
,	O
marked	O
as	O
received	O
by	O
the	O
destination	O
machine	O
,	O
and	O
"	O
unloaded	O
"	O
on	O
return	O
to	O
the	O
sender	O
;	O
thus	O
in	O
principle	O
,	O
there	O
could	O
be	O
as	O
many	O
simultaneous	O
senders	O
as	O
packets	B-Protocol
.	O
</s>
<s>
The	O
network	O
ran	O
over	O
twin	O
twisted-pair	O
cabling	O
(	O
plus	O
a	O
fibre-optic	B-Architecture
section	O
)	O
.	O
</s>
<s>
There	O
are	O
strong	O
similarities	O
between	O
the	O
Cambridge	B-General_Concept
Ring	I-General_Concept
and	O
an	O
earlier	O
ring	B-Architecture
network	I-Architecture
developed	O
at	O
Bell	O
Labs	O
based	O
on	O
a	O
design	O
by	O
John	O
R	O
.	O
Pierce	O
.	O
</s>
<s>
That	O
network	O
used	O
T1	B-Protocol
lines	I-Protocol
at	O
bit	O
rate	O
of	O
1.544	O
MHz	O
and	O
accommodating	O
522	O
bit	O
messages	O
(	O
data	O
plus	O
address	O
)	O
.	O
</s>
<s>
In	O
2002	O
,	O
the	O
Computer	O
Laboratory	O
launched	O
a	O
graduate	O
society	O
called	O
the	O
Cambridge	O
Computer	O
Lab	O
Ring	O
named	O
after	O
the	O
Cambridge	B-General_Concept
Ring	I-General_Concept
.	O
</s>
