From The Free On-line Dictionary of Computing (19 January 2023):
notwork
nyetwork
<networking, humour> /not'werk/ A network that is performing
badly.
Said at IBM to have originally referred to a particular period
of flakiness on IBM's VNET corporate network ca. 1988; but
there are independent reports of the term from elsewhere.
The joke sounds better in Russian, where "nyet" means "no",
hence nyetwork /nyet'werk/.
(2009-05-28)