| Abbreviation | Definition |
|---|---|
| NGOSS | Next Generation Operations Support System |
| NGT | New Global Telecom |
| NGTS | Next Generation Telephony Service |
| NI | Network Interface |
| NI-1 | National ISDN-1 (Integrated Services Digital Network) |
| NI-2 | National ISDN-2 (Integrated Services Digital Network) |
| NIFTE | National Institute For Telecommunication Education |
| NIR | Network Impact Report |
| NIR | Network Information Repository |
| NITI | National Indian Telecommunications Institute |
| NITZ | Network Identity and Time Zone |
| NIU | Network Interface Unit |
| NL | Not Listed |
| NLPID | Network Level Protocol IDentifier |
| NLU | Number Look-Up |
| NM | Newsmage |
| NMA | Network Management and Administration |
| NMA | Network Monitoring and Analysis |
| NMF | Network Management Forum |
| NMI | National Metering Identifier |