| 1.TR.6 | 100BaseFX | 100BaseT | 100BaseTX | 100BaseVG |
| 10base2 | 10base5 | 10baseT | 3Com Corporation | 3Station |
| 802.11a | 802.11b | 802.11g | AARP probe packets | ABP |
| ANSI Z39.50 | ARCnet | AS | ATM Forum | Acceptable Use Policy |
| Access Control List | Active Measurement Project | Active Monitor | Address Resolution Protocol | Administration Management Domain |
| Administrative Domain | Advanced Communication Function/Network Control Program | Advanced Communications Function | Advanced Network Systems Architecture | Advanced Peer-to-Peer Networking |
| Advanced Program-to-Program Communications | Advanced Research Projects Agency Network | Aimnet | Aloha | Aloha Net |
| Alternating bit protocol | Aminet | Apple Address Resolution Protocol | Apple Attachment Unit Interface | AppleTalk Filing Protocol |
| Appletalk | Application Protocol Data Unit | Application Service Element | Arcade | Artisoft, Inc. |
| Association Control Service Element | Attachment Unit Interface | Autonomous System | Autonomous System Number | BITNET |
| Backup Domain Controller | Basic Service Set | Berkeley Internet Name Domain | BitTorrent | BottomFeeder |
| CAP | CCS | CIX | CNAME | COMNET |
| CTCP | Challenge-Handshake Authentication Protocol | Chernobyl packet | Christmas tree packet | Classless Inter-Domain Routing |
| Client To Client Protocol | Clos network | Columbia AppleTalk Package | Commercial Internet eXchange | Common Architecture for Next Generation Internet Protocol |
| Common Communication Services | Common ISDN Application Programming Interface | Common Management Information Services | Competitive Access Provider | Compressed SLIP |
| Cooperative Information System | DLL | DLUR/DLUS | DOS requester | Data Link Connection Identifier |
