A
• AAL: ATM Adaptation Layer
• ABM: Asynchronous Balance Mode
• ABR: Available Bit Rate
• AC: Access Control
• ACK: Acknowledgment
• ADSL: Asymmetric Digital Subscriber Links
• ANI: Automatic Number Identification
• ANSI: American National Standards Institute
• API: Application Programming Interface
• ARM: Asynchronous Response Mode
• ARP: Address Resolution Protocol
• ATM: Asynchronous Transfer Mode
• AU: Access Unit

B
• BCC: Block Check Characters
• BCD: Binary Coded Decimal
• BER: Bit Error Rate
• BGP: Border Gateway Protocol
• BIP: Bit Interleaved Parity
• B-ISDN: Broadband Integrated Services Digital Network
• B-NT: Broadband Network Terminator
• BOM: Beginning of Message
• BootP: Bootstrap Protocol
• bps: Bits per second or bytes per second
• BRI: Basic Rate Interface
• B-TA: Broadband Terminal Adapter
• B-TE: Broadband Terminal Equipment

C
• CAD/CAM: Computer Aided Design/Computer-Aided Manufacturing
• CBR: Constant Bit Rate
• CCI: Carrier-to-Carrier Interface
• CE: Connection Endpoint
• CIR: Committed Information Rate
• CLEC: Competitive Local Exchange Carrier
• CLLM: Consolidated Link Layer Management (FR)
• CLNP: Connectionless Layer Network Protocol
• CLNS: ConnectionLess Network Service
• CLSF: ConnectionLess Server Function
• CMIP: Common Management Interface Protocol
• CMIS: Common Management Information Service
• CMT: Connection Management
• CNMS: Customer Network Management System
• CO: Central Office
• COM: Continuation of Message
• CRC: Cyclic Redundancy Check or Test
• CSMA/CD: Carrier-Sense Multiple Access with Collision Detection
• CSU: Channel Service Unit

D
• DAL: Dedicated Access Line
• DAS: Dual-Attach Station connection
• DCE: Data Communications Equipment
• DCS: Digital Cross-connect System
• DDD: Direct Distance Dialing
• DDS: Digital Data Service
• DHCP: Dynamic Host Configuration Protocol
• DLCI: Data Link Connection Identifier
• DNIS: Directory Number Information Service
• DNS: Distributed Naming Service
• DPG Dedicated Packet Group
• DQDB: Distributed Queue Dual Bus
• DSAP: Destination Service Access Point
• DSG: Default Slot Generator
• DSP: Digital Signal Processor
• DSU: Data Service Unit
• DTE: Data Terminal Equipment
• DTMF: Dual Tone MultiFrequency
• DVMRP: Distance Vector Multicast Routing Protocol
• DXC: Digital Cross-Connect
• DXI: Data Exchange Interface

E
• EA: Extended Address
• ECN: Explicit Congestion Notification
• EGP: Exterior Gateway Protocol
• EGRP: Exterior Gateway Routing Protocol
• EIA: Electronics Industries Association
• EIGRP: Enhanced Interior Gateway Routing Protocol
• EIR: Excess Information Rate
• EOM: End Of Message
• EOT: End Of Transmission
• ES: End System
• ES-IS: End System-to-Intermediate System protocol
• ETSI: European Telecommunications Standards Institute
• ETX: End of Text

F
• FC: Frame Control
• FCS: Frame Check Sequence
• FDDI: Fiber Distributed Data Interface
• FDM: Frequency Division Multiplexing
• FEC: Forward Error Correction
• FECN: Forward Explicit Congestion Notification
• FIFO: First In First Out
• FM: Frequency Modulation
• FOIRL Fiber-Optic InterRepeater Link
• FPS: Frames per second
• FR: Frame Relay
• FRAD: Frame Relay Assembler/Disassembler, or Access Device
• FTP: File Transfer Protocol

G
• Gbit: Gigabits
• Gbps: Gigabits per second
• GOS: Grade of Service
• GUI: Graphical User Interface

H
• HCS: Header Check Sequence
• HDLC: High-Level Data Link Control
• HEC: Header Error Control
• HSSI: High-Speed Serial Interface
• HTML: Hypertext Markup Language
• HTTP: Hypertext Trasfer Protocol

I
• ICMP: Internet Control Message Protocol
• IDRP: Inter Domain Routing Protocol
• IEEE: Institute of Electrical and Electronics Engineers
• IGRP: Interior Gateway Routing Protocol
• I-MAC: Isochronous Media Access Control
• ISN: Initial Sequence Number
• IP: Internet Protocol
• IPCP: Internet Protocol Control Protocol
• ISDN: Integrated Services Digital Network
• ISDU: Isochronous Service Data Unit
• ISP: Internet Service Protocol
• ITU: International Telecommunications Union
• IVR: Integrated Voice Recognition

K
• kbit: kilo bit
• kbps: kilo bits per second

L
• LAN: Local Area Network
• LAT: Local Area Transport protocol
• LCGN: Logical Channel Group Number
• LCP: Link Control Protocol
• LES: LAN Emulation Server
• LLC: Logical Link Control
• LME: Layer Management Entity
• LMI: Local Management Interface
• LSB: Least Significant Bit
• LTE: Line Terminating Equipment
• LU: Logical Unit

M
• MAC: Media Access Control
• MAN: Metropolitan Area Network
• Mbps: Megabits per second
• MCP: MAC Convergence Protocol
• MHz: Megahertz
• MIB: Management Information Base
• MIPS: Millions of Instructions Per Second
• MOP: Maintenance and Operation Protocol
• MSAP: MAC Service Access Point
• MSB: Most Significant Bit
• MUX: Multiplexer

N
• NBP: Name Binding Protocol
• NCP: Network Control Protocol or Point
• NE: Network Element
• NFS: Network File Server
• NIC: Network Interface Card
• NNI: Network-Node Interface
• NOS: Network Operating System
• NRM: Normalized Response Mode
• NRZ: Non-return to zero

O
• OAM: Operations and Maintenance
• OCR: Optical Character Recognition
• ONA: Open Network Architecture
• OSI: Open Systems Interconnection
• OSPF: Open Shortest Path First

P
• PABX: Private Automatic Branch Exchange
• PBX: Private Branch Exchange
• PCN: Personal Communications Network
• PCS: Personal Communications Services
• PDC: Packet Data Channel
• PDN: Public Data Network
• PDU: Protocol Data Unit
• PID: Protocol IDentification
• PING: Packet Internet Groper
• PIR: Protocol Independent Routing
• PLCP: Physical Layer Convergence Protocol
• PON: Passive Optical Network
• PoP: Point of Presence
• POTS: Plain Old Telephone Service
• PPP: Point-to-Point Protocol
• Pps: Packets per second
• PRI: Primary Rate Interface
• PSPDN: Packet-Switched Public Data Network
• PT: Payload Type
• PTE: Path-Terminating Equipment (PTE)
• PVC: Permanent Virtual Circuit or Channel

Q
• QAF: Queued Arbitrated Function
• QoS: Quality of Service

R
• RCP: Remote Console Protocol
• RDI: Remote Defect Indication
• RIP: Routing Information Protocol
• RISC: Reduced Instruction Set Computer
• RMT: Ring Management
• RNR: Receive Not Ready
• RQ: Request Counter
• RR: Receive Ready
• RSVP: Resource Reservation Protocol
• RTMP: Routing and Management Protocol

S
• SAP: Service Access Point
• SAR: Segmentation and Re-assembly
• SAS: Single-Attach Station
• SDLC: Synchronous Data Link Control protocol
• SDU: Service Data Unit
• SIR: Sustained Information Rate
• SMDS: Switched Multi-megabit Data Service
• SMT: System Management protocol
• SMTP: Simple Mail Transfer Protocol
• SN: Sequence Number
• SNI: Subscriber Network Interface
• SNMP: Simple Network Management Protocol
• SONET: Synchronous Optical Network
• SREJ: Select Reject frame
• SRT: Source Route Transparent protocol
• SSAP: Source Service Access Point
• SSCOP: Service-Specific Connection Oriented Protocol
• STM: Synchronous Transfer Mode
• STP: Shielded Twisted Pair
• STP: Spanning Tree Protocol

T
• TA: Terminal Adapter
• TAPI: Telephony Application Program Interface
• TCP: Transmission Control Protocol
• TCP/IP: Transmission Control Protocol/Internet Protocol
• TDM: Time Division Multiplexing
• TE: Terminal Equipment

U
• UBR: Unspecified Bit Rate
• UDP: User Datagram Protocol
• UNI: User-to-Network Interface
• UNMA: Unified Network Management Architecture
• UTP: Unshielded Twisted Pair

V
• VBR: Variable Bit Rate
• VCI: Virtual Channel or Circuit Identifier
• VP: Virtual Path
• VPN: Virtual Private Network

W
• WAN: Wide Area Network

X
• XNS: Xerox Network Systems protocol

Z
• ZIP: Zone Information Protocol