AAL   ATM Adaptation Layer

AARP  AppleTalk Address Resolution Protocol

ABM  Asynchronous Balance Mode 

ABR  Available Bit Rate

AC   Access Control 

ACF  Access Control Field 

ACK  Acknowledgment

ADM  Add/Drop Multiplexer

ADSL  Asymmetric Digital Subscriber Links

AIS   Alarm Indication Signal 

ANI   Automatic Number Identification

ANS   American National Standards

ANSI  American National Standards Institute

API   Application Programming Interface 

BCC    Block Check Characters

BCD    Binary Coded Decimal

BECN   Backward Explicit Congestion Notification 

BER    Bit Error Ratio or Rate

BGP    Border Gateway Protocol

BIP    Bit Interleaved Parity 

B-ISDN Broadband Integrated Services Digital Network