- AAL – Application Adaptation Layer
- ABM – Asynchronous balanced mode
- ABR – Available Bit Rate
- AC – Access Control
- ACK – Acknowledgment
- ADSL – Asymmetric Digital Subscriber line
- AM – Amplitude Modulation
- AMI – Alternate Mark Inversion
- ANSI – American National Standards Institute
- ARM – Asynchronous Response Mode
- ARP – Address Resolution Protocol
- ARPA – Advanced Research Project Agency
- ARPANET – Advanced Research Project Agency Network
- ARQ – Automatic Repeat Request
- ASCII – American Standard Code For Information Interchange
- ASK – Amplitude Shifted Key
- ASN.1 – Abstract Syntax Notation 1
- ATM – Asynchronous Transfer Mode
- AUI – Attachment Unit Interface
- B-ISDN – Broadband ISDN
- B8ZS – Bipolar 8 Zero Substitution
- BBC – Block Check Count
- BECN – Backward Explicit Congestion Notification
- BER – Basic Encoding Rule
- BLAST – Blocked Asynchronous Transmission
- BOOTP – Bootstrap Protocol
- BRI – Basic Rate Interface
- BSC – Binary Synchronous Communication
- BUS – Broadcast/Unknown server
- CAP – Carrierless Amplitude/Phase
- CBR – Constant Bit Rate
- CDV – Cell Delay variation
- CER – Cell Error Ratio
- CGI – Common Gateway Interface
- CHAP – Challenge Handshake Authentication Protocol
- CIR – Committed Information Rate
- CLNS – Connectionless Network Service
- CLR – Cell Loss Ratio
- CLTS – Connectionless Transport Service
- CMIP – Common Management Information Protocol
- CMIS – Common Management Information Service
- CMISE – Common Management Information Service Element
- CONS – Connection-Oriented Network Service
- COTS – Connection-Oriented Transport Service
- CRC – Cyclic Redundancy Check
- CS – Convergence Sublayer
- CSMA – Carrier Sense Multiple Access
- CSMA/CD – Carrier Sense Multiple access with Collision Detection
- CSU – Channel Service Unit
- CTD – Cell transfer Delay
- CVDT – Cell Variation Delay Tolerance
- DAC – Dual Attachment concentrator
- DAS – Dual attachment Station
- DC – Direct Current
- DCE – Data Circuit-Terminating equipment
- DDS – Digital Data service
- DES – Data Encrypted Service
- DHCP – Dynamic Host Configuration protocol
- DIB – Directory Information Base
- DLCI – Data Link Connection Identifier
- DMT – Discrete Multitone Technique
- DNS – Domain Name System
- DPSK – Differential Phase Shift Keying
- DQDB – Distributed Queue Dual Bus
- DS – Directory Service
- DSA – Digital Subscriber Line
- DSL – Digital Subscriber Line
- DSU – Digital Service Unit
- DSU/CSU – Digital Service Unit/Channel Service Unit
- DTE – Data Terminal Equipment
- DUA – Directory Unit Agent
- EHF – Extremely High Frequency
- EIA – Electronics Industries Association
- EMI – Electromagnetic Interference
- ENQ/ACK – Enquiry/Acknowledgement
- EOT – End Of Transmission
- FCC – Federal communications Commission
- FDDI – Fiber Distributed Data Interface
- FDM – Frequency-Division Multiplexing
- FECN – Forward Explicit congestion Notification
- FM – Frequency Modulation
- FRAD – Frame Relay Assembler/Disassembler
- FSK – Frequency Shift Keying
- FTAM – File Transfer, Access, and Management
- FTP – File Transfer Protocol
- FTTC – Fiber To The Curb
- GFI – general Format Identifier
- HDB3 – High-Density Bipolar 3
- HDLC – High Level Data Link Control
- HDSL – High Bit Rate Digital subscriber Line
- HF – High Frequency
- HTML – Hyper Text Markup Language
- HTTP – Hyper Text Transfer Protocol
- ICMP – Internet Control Message Protocol
- IDN – Integrated Digital Network
- IEEE – Institute Of Electrical And Electronics Engineers
- IGMP – Internet Group Message Protocol
- IP – Internet Protocol
- IPCP – Internet Protocol Control Protocol
- IPNG – IP Next Generation
- ISDN – Internet Service Digital Network
- ISO – International Standards organization
- ISOC – Internet Society
- ITU-T – International Telecommunications Union-Telecommunication Standardization Sector
- JPEG – Joint photographic Experts Group
- LAN – Local Area Network
- LANE – Local Area Network Emulation
- LAPB – Line Access Procedure, Balanced
- LAPM – Link Access Procedure For Modems
- LCN – Logical Channel Number
- LCP – Link Control Protocol
- LEC – LANE Client
- LED – Light-Emitting Diode
- LES – LANE Server
- LF – Low Frequency
- LLC – Logical Link Control
- LMI – Local Management Information
- LRC – Longitudinal Redundancy Check
- LSP – Link State Packet
- LZW – Lempel-Ziv-Welch
- MA – Multiple Access
- MAC – Medium Access Control
- MAN – Metropolitan Area Network
- MAU – Multi station Access Unit Or Medium Attachment Unit
- MCR – Minimum Cell Rate
- MF – Middle Frequency
- MHS – Message Handling System
- MIB – Management Information base
- MIC – Media Interface Connector
- MIME – Multipurpose Internet Mail Access
- MPEG – Motion Picture experts Group
- MTA – Message Transfer agent Or Mail Transfer Agent
- MTS – Message Transfer System
- MTSO – Mobile Telephone Switching office
- MTU – Maximum Transfer unit
- NAK – NegativeAcknowledgement
- NCP – Network Control Protocol
- NIC – Network Interface Card
- NNI – Network-To-Network Interface
- NRM – Normal Response Mode
- NRZ – Non return To Zero
- NRZ-I – Non return To Zero, Invert
- NRZ-L – Non return To Zero, Level
- NT1 – Network Termination 1
- NT2 – Network termination 2
- NVT – Network Virtual Terminal
- OSI – Open System Interconnection
- P/F – Poll/Final
- PAD – Packet Assembler/Disassembler
- PAM – Pulse Amplitude Modulation
- PAP – Password Authentication Protocol
- PBX – Private Branch Exchange
- PCM – Pulse Code Modulation
- PCR – Peak Cell Rate
- PDU – Protocol Data unit
- PLP – packet Layer Protocol
- PM – Phase Modulation
- POP – Post Office Protocol
- PPP – Point-To-Point Protocol
- PRI – Primary Rate Interface
- PSK – Phase Shift Keying
- PSTN – Public Switched Telephone Network
- PTI – Packet Type Identifier
- PVC – Permanent Virtual Circuit
- QAM – Quadrature Amplitude Modulation
- QOS – Quality Of Service
- RADSL – Rate Adaptive Asymmetrical Digital Subscriber Line
- RIP – Reverse Information Protocol
- RSA –  Rivest, Shamir, Adleman
- RZ – Return to Zero
- SAPI – Service Access Point Identifier
- SAR – Segmentation And Reassembly
- SAS – Single Attachment Station
- SCR – Sustained Cell Rate
- SDH – Synchronous Digital Hierarchy
- SDSL – Symmetric Digital Subscriber Line
- SDLC – Synchronous Data Link Control
- SFD – Start Frame Delimiter
- SHF – Super High Frequency
- SIP – SMDS Interface Protocol
- SLIP – Serial Line Internet Protocol
- SMDS – Switched Multimegabit Data Service
- SMI – Structure of Management Information
- SMTP – Simple Mail Transfer Protocol
- SNMP – Simple Network Management Protocol
- SONET – Synchronous Optical Network
- SPDU – Session Protocol Data Unit
- STM – Synchronous Transport Module
- STP – Shielded Twisted-pair
- STS – Synchronous transport Signal
- SVC – Switched virtual Circuit
- TA – Terminal adapter
- TCP – Transmission Control Protocol
- TCP/IP – Transmission Control protocol/Internet Protocol
- TDM – time-Division Multiplexing
- TE1 – Terminal Equipment 1
- TE2 – Terminal Equipment 2
- TEI – terminal equipment Identifier
- TELNET – Terminal Network
- TFTP – Trivial File transport protocol
- TP – Transmission Path
- TPDU – Transport Protocol Data Unit
- TSI – Time-Slot Interchange
- TTL – Time To live
- UA – User Agent
- UBR – Unspecified Bit Rate
- UDP – User Datagram protocol
- UHF – Ultrahigh Frequency
- UNI – User-To-Network interface
- URL – Uniform Resource locator
- UTP – Unshielded Twisted-Pair
- VBR – Variable Bit Rate
- VBR-NRT – Variable Bit Rate Non real time
- VBR-RT – Variable Bit Rate Real time
- VC – Virtual Circuit
- VCI – Virtual Circuit Identifier
- VDSL – Very High Bit Rate Digital Subscriber Line
- VHF – Very High Frequency
- VLF – Very Low Frequency
- VOFR – Voice Over frame Relay
- VP – Virtual Path
- VPI – Virtual Path Identifier
- VPI/VCI – Virtual Path Identifier/virtual channel Identifier
- VRC – Vertical Redundancy Check
- VT – Virtual Terminal/virtual tributary
- WAN – Wide Area Network
- WDM – Wave-Division Multiplexing
- WWW – World Wide Web