| JPEG | Joint Photographic Experts Group |
| LAN | Local Area Network |
| LAPM | Linked Access Procedure for Modems |
| LDAP | Lightweight Directory Access Protocol |
| LSA | Local Security Authority (Windows NT) |
| LSL | Link Support Layer |
| LSP | Link State Protocol |
| MAC | Media Access Control |
| MIME | Multipurpose Internet Mail Extensions |
| MIT | Massachusetts Institute of Technology |
| MJD | Modified Julian Day |
| MLI | Multiple Link Interface |
| MLID | Multiple Link Interface Driver |
| MNP | Microcom Network Protocol |
| MPI | Multiple Protocol Interface |
| MPR | Multi Provider Router |
| MSFS | MailSlot File System |
| MTF | Master File Table |
| MTS | Microsoft Transaction Server |
| MTU | Maximum Transfer Unit |
| MSM | Media Support Module |
| MUP | Multiple Universal naming convention Provider |
| NAT | Network Address Translation |
| NBF | NetBEUI Frame |
| NBFP | NetBIOS Frame Protocol |
| NBNS | NetBios Name Server |
| NCB | Network Control Block |
| NCPA | Network Control Panel Application |
| NCSA | National Center for Supercomputing Applications |
| NDIS | Network Driver Interface Specification |
| NetBEUI | NetBIOS Extended User Interface |
| NetBIOS | Network Basic Input/Output System |
| NIC | Network Interface Card |
| NIS | Network Information System |
| NNTP | Network News Transfer Protocol |
| NPFS | Named Pipe File System |
| NSTC | National Science and Technology Council |
| NTFS | NT File System |
| NTP | Network Time Protocol |
| OBR | Optical ByPass Relay |
| ODI | Open Data-Link Interface |
| OEM | Original Equipment Manufacturer |
| OSI | Open Systems Interconnect |
| OSPF | Open Shortest Path First |
| OUI | Organizationally Unique Identifier |
| PCI | Peripheral Component Interconnect |
| PCMCIA | Personal Computer Memory Card International Association |
| PCT | Private Communication Technology |
| PDC | Primary Domain Controller (Windows NT) |
| PGP | Pretty Good Privacy |
| PMC | PCI Mezzanine Card |
| PMD | Packet Mode Data |
| PMTU | Path Maximum Transfer Unit |
| PNG | Portable Network Graphics |
| PNNI | Private Network to Network Interface |
| POP | Post Office Protocol |
| POP | Point Of Presence |
| PPP | Point to Point Protocol |
| PPTP | Point-to-Point Tunneling Protocol |
| PSE | Packet Switching Exchange |
| PUP | PARC Universal Protocol |
| QOS | Quality Of Service |
| RAS | Remote Access Service |
| RDSI | Red Digital de Servicios Integrados |
| RIP | Routing Internet Protocol |
| RFC | Request For Comment |
| RPC | Remote procedure call |
| RPI | Rockwell Protocol Interface |
| RSA | Rivest, Shamir & Adelman (cryptohgraphic number) |
| RSF | Russian Space Forces |
| RTB | Red Telefónica Básica |
| SAM | Security Accounts Manager (Windows NT) |
| SAS | Single Attached Station |
| SCM | Service Control Manager (Windows NT) |
| SDRAM | Syncrhonous Dynamic Random Access Memory |
| SEPP | Secure Electronic Payment Protocol |
| SET | Secure Electronic Transactions |
| SGML | Standard Generalized Marked Language |
| SIMM | Single In-line Memory Module |
| SLIP | Serial Line Internet Protocol |
| SMB | Server Message Block |
| SMTP | Simple Mail Transfer Protocol |
| SNMP | Simple Network Management Protocol |
| SPD | Serial Presence Detect |
| SSL | Secure Sockets Layer |
| STT | Secure Transaction Technology |
| TAI | International Atomic Time |
| TCB | Trusted Computing Base |
| Barycentric Coordinate Time | |
| TCP | Transmission Control Protocol |
| TCG | Geocentric Coordinate Time |
| TDI | Transport Data Interface |
| TDP | Tag Distribution Protocol |
| TIB | Tag Information Base |
| TSM | Topology Support Module |
| TSV | Tab Separated Values |
| TT | Terrestrial Time |
| TDB | Barycentric Dynamical Time |
| TDT | Terrestrial Dynamical Time |
| TTD | Telefónica Transmisión de Datos |
| TTL | Time To Live |