| Abbreviation | Definition |
|---|---|
| A/CH | Alternate CHannel |
| A2LD | Alternative 2nd Level Domain |
| A2N | Access 2 Networks |
| A2P | Application To Peer |
| AA | Access Authorization |
| AAA | Authentication Authorization and Accounting |
| AAA | Authentication, Authorization, and Accounting |
| AAAN | Arab American Action Network |
| AAC | Anime Art Club |
| AACAN | Africa America Crisis Assistance Network |
| AADT | Average Annual Daily Traffic |
| AAGE | Analytics Acceleration Grid Environment |
| AAI | ACTS ATM Internetwork |
| AAL | Access Activity Log |
| AAL | Add A Leaf |
| AAL | Application Adaptation layer |
| AAL | ATM Adaptation Layer |
| AALPS | Automated Activity Log Preparation System |
| AAMH | Alternate Adaptive Minimum Hop |
| AANE | Add A New Entry |