WordNet (r) 3.0 (2006):

NOC
    n 1: an undercover agent who is given no official cover

V.E.R.A. -- Virtual Entity of Relevant Acronyms (February 2016):

NOC
       Network Operations Center


The Free On-line Dictionary of Computing (30 December 2018):

Network Operations Center
NOC

   (NOC) A location from which the operation of a network or
   internet is monitored.  Additionally, this center usually
   serves as a clearinghouse for connectivity problems and
   efforts to resolve those problems.

   See also Network Information Center.

   (1994-12-01)