HBFG - Host Behavior Functional Group (ATM Forum, MPOA SWG)

HDLC - High speed Data Link Control

HDSL - High-bit-rate Digital Subscriber Line

HDTV - High Definition Television

HEC - Header Error Control

HEC - Header Error Check

HF - High Frequency

HLS - Hue-Lightness-Saturation

HPPI - High Performance Parallel Interface

HSSI - High Speed Serial Interface

HTML - Hypertext Markup Language

HTTP - Hypertext Transfer Protocol

HV - High Voltage

Hz - Hertz

I&R - Installation And Repair

IAB - Internet Activities Board

IANA - Internet Assigned Numbers Authority

IASG - Internetwork Address Sub-Group (ATM Forum, MPOA SWG)

IBSG - Internetwork Broadcast Sub-Group (ATM Forum, MPOA SWG)

IBUFG - Internetwork Broadcast/Unknown Functional Group (ATM Forum, MPOA SWG)

IC - Integrated Circuit

ICFG - IASG Coordinating Function Group (ATM Forum, MPOA SWG)

ICI - Inter-Carrier Interface

ICMP - Internet Control Message Protocol

IDN - Integrated Digital Network

IDP - Initial Domain Part

IDRP - Inter-Domain Routing Protocol

IDSL - ISDN Digital Subscriber Line

IDU - Interface Data Unit (UNI 3.0)

IE - Information Element

IEC - Inter-Exchange Carrier

IEE - Institution of Electrical Engineers

IEEE - Institute of Electrical and Electronic Engineers

IESG - Internet Engineering Steering Group

IETF - Internet Engineering Task Force

IGMP - Internet Group Management Protocol

IGP - Internal (Interior) Gateway Protocol

IGRP - Internal (Interior) Gateway Routing Protocol

IISP - Interim Inter-Switch Signaling Protocal (P-NNI Phase 0)

ILMI - Interim Local Management Interface

IN - Intelligent Network

I/O - Input/Output

IP - Internet Protocol

IPI - Intelligent Peripheral Interface

I-PNNI - Integrated PNNI

IPX - Internet Packet Exchange

IR - Infra-Red Controller

ISDN - Integrated Services Digital Network

IS-IS - Intermediate System-to-Intermediate System

ISO - International Standards Organization

ISOC - Internet Society

ISP - Internet Service Provider

ITU - International Telecommunications Union (formerly CCITT)

ITU-T - International Telecommunications Union Telecommunication Standardization Sector

IWF - Inter-Working Function

IXC - Inter eXchange Carrier

Kbps - Kilo bits per second

KHz - Kilohertz

KVA - Kilovolt amperes

KW - Kilowatts

KWh - Kilowatt Hours