The period 1989 - 1994:
The FEL local area network (FELLAN) was expanded fast. Using thin Ethernet to provide
the interconnection between the FELLAN backbone and the connectors in the Laboratory rooms,
the cost per connection decreased from Dfl 1200 to Dfl 400.
At the end of 1991, all for 1992 and 1993 planned connections were realised.
To compartment any signal errors and to keep high data traffic volumes as much local as possible,
the repeaters that interconnected FELLAN segments were replaced by secure bridges and routers.
In 1994, classified network cells were connected with the central computer room in order
to provide central backup services.
Highly secured DES encryption
Early 1990, as part of a security evaluation project, the TNO-FEL
obtained three DES encryptor units for the secure encryption of LAN traffic.
Obtaining the required US export licences took many months.
When the computer vendor delivered and installed the table top units, it was decided to convert them into
a rackmount model and to mount them into a standard 19 inch
rack. This required the removal of the plastic enclosure of the units.
As the units were on loan, we did not want to loose any part. Thus the "legs" of the units were screwed in again.
Unfortunately, the lengths of the screwthread was a couple of millimeters too long for this unforeseen configuration.
The screw shorted circuits the main board causing burned components in two of the three DES units.
As the delivery of spare parts required the same export process and additional delays were caused by the fact that
the DES units were on loan, the "red-tape"
export procedure required another couple of months. The manufacturer decided to make a change in the design of the
DES encryption units by providing a different type of legs with less screw thread.