TABLE OF CONTENTS | A-links | Access links |
| AAL | ATM adaptation layer |
| ABOM | A-bis Operations and Maintenance |
| AC | Authentication center |
| ACD | Automatic call distribution |
| ACG | Automatic code gap |
| ACM | Address complete message |
| AE | Application entity |
| AERM | Alignment error rate monitor |
| AIN | Advanced Intelligent Networks |
| AK | Data acknowledgment |
| AMI | Alternate mark inversion |
| ANI | Automatic number identification |
| ANM | Answer message |
| ANSI | American National Standards Institute |
| ASE | Application service element |
| ASN-1 | Abstract Syntax Notation One |
| ASP | Application service part |
| ATM | Asynchronous Transfer Mode |
| B-links | Bridge links |
| BIB | Backward indicator bit |
| BISDN | Broadband ISDN |
| BISUP | Broadband ISUP |
| BITS | Building integrated timing system |
| BLA | Blocking acknowledgment (message) |
| BLO | Blocking (message) |
| BOP | Bit-oriented protocol |
| BRI | Basic rate ISDN |
| BSC | Base station controller |
| BSDB | Business service database |
| BSN | Backward sequence number |
| BSS | Base station subsystem |
| BSSMAP | Base Station Subsystem Mobile Application Part |
| BTA | Basic trading area |
| BTS | Base transceiver station |
| BTSM | Base Transceiver Station Management |
| C-links | Cross-links |
| CAE | Communications Applications Environment |
| CBA | Changeback acknowledgment (message) |
| CBD | Changeback declaration (message) |
| CC | Connection confirmed (message) |
| CCE | Consistency check end (message) |
| CCEA | Consistency check end acknowledgment (message) |
| CCR | Continuity check request (message) |
| CCRA | Consistency check request acknowledgment (message) |
| CCS | Common channel signaling |
| CD | Carrier detect |
| CESID | Callers Emergency Service Identification |
| CFN | Confusion (message) |
| CGB | Circuit group blocking (message) |
| CGBA | Circuit group blocking acknowledgment (message) |
| CGU | Circuit group unblocking (message) |
| CGUA | Circuit group unblocking acknowledgment (message) |
| CIC | Circuit identification code |
| CLLI | Common Language Location Identifier |
| CMC | Call modification completed (message) |
| CMR | Call modification request (message) |
| CMRJ | Call modification reject (message) |
| CMSDB | Call management services database (message) |
