- NACS NetWare Asynchronous Communications Server
- NAK Negative AcKnowledgement
- NASI Network Asynchronous Services Interface / NetWare Asynchronous Services Interface
- NAU Network Addressable Unit
- NAUN Nearest Active Upstream Neighbor
- NBP Name Binding Protocol
- NCIC National Crime Information Computer
- NCP Network Control Program
- NCS Network Connect Services
- NCSA National Center for Supercomputing Applications
- NCSI Network Communications Services Interface
- NDIS Network Driver Interface Standard
- NEARNET New England Academic and Research NETwork
- NED NASA Extragalactic Database
- NEP Network Entry Point
- NEST Novell Embedded Systems Technology
- NetBEUI NetBIOS Extended User Interface
- NETBIOS NETwork Basic Input/Output System
- NEXT Near End Cross (X) Talk
- NFS Network File System
- NIC Network Interface Card / Network Interface Controller / Network Information Center
- NICE Network Information and Control Exchange
- NII National Information Infrastructure
- NIS Network Information Services / Names Information Socket
- NISO National Information Standards Organization
- NIST National Institute of Standards and Technology
- NLM Network Loadable Module / NetWare Loadable Module
- NLSP Network Link Services Protocol
- NMI NonMaskable Interrupt
- NMS Network Management Station
- nn no news is good news
- NNTP Net News Transport Protocol / Network News Transport Protocol
- NOC Network Operations Center
- NOS Network Operating System
- NPTN National Public Telecommunications Network / National Public Telecomputing Network
- NREN Nationals Research and Education Network
- NRZ Non-Return to Zero
- ns nanosecond
- NSF National Science Foundation
- NSIC National Storage Industry Consortium
- NSP Network Services Protocol / Native Signal Processing
- NSS Nodal Switching Station
- NSTL National Software Testing Laboratories
- NT Network Termination / Nested Task
- NTP Network Time Protocol
- NTSC National Television Standards Committee
- NVEs Network Visible Entities
- NVRAM Non-Volatile Random Access Memory