| Abbreviation | Definition |
|---|---|
| ARP | Address Resolution Protocol |
| ARPT | Autorité de régulation des postes et télécommunications |
| ARPU | Average Revenue Per User |
| ARS | Automatic Route Selection |
| AS56 | Access System Centum 56 series |
| ASA | Avaya Site Administration |
| ASB | Application-Specific Bit |
| ASD | Alternative Service Delivery |
| ASE | Accredited Systems Engineer |
| ASIC | Application Specific Instruction Code |
| ASLV | Augumented Satellite Launch Vehicle |
| ASM | Attached Sync Marker |
| ASN.1 | Abstract Syntax Notation One |
| ASP | Active Signaling Protocol |
| ASP | Application Service Provider |
| ASPECT | Automation Signalling Performance Equipment Control And Telecommunications |
| ASR | Access Service Request |
| ASR | Answer Seizure Ratio |
| ASTE | Advanced Systems And Telecommunications Equipment |
| ASU | Arbitrary Strength Unit |