I/O Input/Output
IAB Internet Architecture Board
IANA Internet Assigned Numbers Authority
IAPP Inter Access Point Protocol
ICI Interexchange Carrier Interface
ICMP Internet Control Message Protocol
ICP Internet Cache Protocol
ICR Intelligent Call Routing
ICS Intelligent Calling System
ICSA International Computer Security Association
ID Identification
IDDD International Direct Dialing Designator
IDPR Inter-Domain Policy Routing
IEC International Electrotechnical Commission
IEEE Institute of Electrical and Electronic Engineers
IESG Internet Engineering Steering Group
IETF Internet Engineering Task Force
IF Intermediate Frequence
IGMP Internet Group Management Protocol
IGP Interior Gateway Protocol
IIS Internet Information Server (Microsoft Corp.)
ILEC Incumbent Local Exchange Carrier
IMAP Internet Mail Access Protocol
IMEI International Mobile Equipment Identity
IMS/VS Information Management System/Virtual Storage (IBM Corp.)
IMSI International Mobile Subscriber Identity
IMT Intelligent Multimode Terminals
IMTS Improved Mobile Telephone Service
IN Intelligent Network
INMARSAT International Maritime Satellite Organization
INMS Integrated Network Management System
IOC Inter Office Channel
IP Internet Protoco
IPH Integrated Packet Handler
IPI Intelligent Peripheral Interface
IPN Intelligent Peripheral Node
IPX Internetwork Packet Exchange
IR Infrared
IRC Internet Relay Chat
IrDA Infrared Data Association
IrLAN Infrared LAN
IrLAP Infrared Link Access Protocol
IrLMP Infrared Link Management Protocol
IrPL Infrared Physical Layer
IRQ Interrupt Request
IrTTP Infrared Transport Protocol
IS Information System
IS Industry Standard
IS-IS Intra-autonomous System to Intraautonomous System
ISA Industry Standard Architecture
ISAPI Internet Server Applications Programming Interface
ISDL ISDN Subscriber Digital Line
ISDN Integrated Services Digital Network
ISM Industrial, Scientific, and Medical (frequency bands)
ISO International Organization for Standardization
ISOC Internet Society
ISP Internet Service Provider
ISR Intermediate Session Routing (IBM Corp.)
ISSI Inter-Switching Systems Interface
IT Information Technology
ITFS Instructional Television Fixed Service
ITG Internet Telephony Gateway
ITR Intelligent Text Retrieval
ITU International Telecommunication Union
IVR Interaction Voice Response
IXC Interexchange Carrier
