Plot putting pressure on computer network (4)
I believe the answer is:
plan
'plot' is the definition.
(I know that plot is a more specific form of the action plan)
'pressure on computer network' is the wordplay.
'pressure' becomes 'p' (abbreviation).
'on' is a charade indicator (letters next to each other).
'computer network' becomes 'LAN' (abbreviation for local-area network).
'p'+'lan'='PLAN'
'putting' acts as a link.
(Other definitions for plan that I've seen before include "Programme" , "Scheme - map" , "Intention or decision about what one is going to do" , "Formulate" , "Scale drawing; scheme" .)