System X is the system used to run the
UK narrowband communications network. Designed by the
GPO and
GEC in the 1970s (the first exchange was rolled out in 1979) System X is the
umbrella term covering both
hardware and
software sitting in the
exchanges (both
local exchanges and
trunk exchanges), that is responsible for setting up
calls,
billing them, and clearing the
connections away.
System X has undergone many permutations, including adaptions to deal with cable telcos, and uncreased processing and switching power, mainly to deal with the hugely increased demand to call time, largely due to the popularity of the Internet (when System X was designed average call time was 2 minutes, it is currently 14 minutes, with a longest call record of 40hrs)