About NPL Architecture: Donald Davies and
his colleagues at the UK National Physical Laboratories independently
developed the idea of packet switching, and developed a UK version of
the
ARPANET. In 1965
Donald
Davies
at the National Physical Lab (NPL) in Britain proposed a country wide
packet communications network. He gave a talk on his proposal in 1966,
and afterwards a person from the Ministry of Defence told him about
Paul Baran's work for RAND being done independently. At the 1967 ACM
Gatlinburg conference, Lawrence Roberts met Donald Davies and Roger
Scantlebury from the NPL, who had published a paper at the conference
called "A Digital Communications Network for Computers". They discovered
that Leonard Kleinrock's work, Baran's work at RAND, and the work at
NPL had been developed independently. It was almost like the idea was
waiting to be developed. In 1970, Davies helped build a packet switched
network called the Mark I to serve the NPL. The Mark I was replaced
with an improved network called the Mark II in 1973, and remained in
operation until 1986, but it never had the funding to develop on the
scale of the ARPANET.
