156 I&M Installation and Maintenance I/O Input/Output IB Instruction Buffer IBM Inferior But Marketable IBM Insidious Black Magic IBM International Business Machines IBM Its Been Malfunctioning IBM Its Better Manually IBN Integrated Business Network IC Independent Carrier IC Inner Circle IC Integrated Circuit IC Inter-Exchange Carrier ICAN Individual Circuit Analysis ICC Interstate Commerce Commission ICD Interactive Call Distribution ICE Inner Circle Elite ICE Insane Creator Enterprises ICE International Communications Echomail ICE Intrusion Countermeasure Electronics ICH International Call Handling ICLID Individual Calling Line Identification ICM Integrated Call Management ICMP Internet Control Message Protocol ICN Interconnecting Network ICPOT InterExchange Carrier-Point of Termination ICR Inductance,Capacitance,Resistance ICS Italian Cracking Service ICST Institute for Computer Sciences and Technology ICUG International Closed User Groups ICVT InComing Verification Trunk IDA Integrated Digital Access IDC Information Distribution Companies IDCI Interim Defined Central Office Interface IDDD International Direct Distance Dialing IDECUS Internal Digital Equipment Corporation User's Society IDG Indigo IDH Inpherno Data Haven IDI Intergalactic Dismantling Incorporated IDLC Integrated Digital Loop Carrier IDN Integrated Digital Networks IEC International ElectroTechnical Commission IED International Engineering Development IEEE Institute of Electrical and Electronic Engineers IEG Internal Equipment Group IF Intermediate Frequency IFIP International Federation for Information Processing IFRPS Intercity Facility Relief Planning System IHA International Hackers Association IIN Integrated Information Network IIRG International Information Retrieval Guild IISF International Information Security Foundation IL Indirect Labor ILL Illuminatus ILS Illusion IM Interface Module IM&T Information and Technology Management IMAS Integrated Mass Announcement System IMG Image Ansi Artists IMM Idle Material Management IMM Input Message Manual IMP Imperial IMS Integrated Management Systems IMT Inter-Machine Trunk IMTS Improved Mobile Telephone Service IN Inch IN Intelligent Network IN/1 Intelligent Network/1 INAP Intelligent Network Access Point INC International Carrier INC International Network of Crackers INL Inter Node Link INN Inter Node Network INS Information Network System INTELSAT International Telecommunications Satellite Consortium INTT Incoming No Test Trunks INV Inventory INWATS Inward Wide Area Telecommunications Service INWATS Inward Wide Area Telephone Service IO Independent Option or Input/Output IO Inward operator IOC Input/Output Controller IOCC International Overseas Completion Center IOP Input-Output Processor IOT Inter-Office Trunk IOWA Inmates of the World Asylum IP Information Provider IP Intermediate Point IP Internet Protocol IPCH Initial Paging Channel IPCS Interactive Problem Control System IPDP Industrial Peripheral Data Processing IPDS Intelligent Printer Data Stream IPG Image Processing Group IPL Initial Program Load IPLAN Integrated Planning And Analysis IPLS InterLATA Private Line Services IPM Impulses Per Minute IPM Interruptions Per Minute IPMO Industry Program Management Office IPS Inches Per Second IPSG Internal Product Strategies Group IPT Inventory Program Team IPX Integrated Packet Exchange IR Immortal Riot IRC International Record Carrier IRC Internet Relay Chat IRG International Rogues Guild IROR Internal Rate of Return IRQ Interrupt Request IRR Internal Rate of Return IS Information Systems IS Interrupt Set ISA International Software Alliance ISA Industry Standard Architecture ISBS Information Systems Business Segment ISC Inter-Nation Switching Center ISC International Switching Center ISD Insane Software Designers ISDN Integrated Service Digital network ISDN Integrated Services Digital Network ISF Information Security Foundation ISLM Integrated Services Line Module ISLU Integrated Services Line Unit ISM Installed Systems Marketing ISN Information Systems Network ISN Integrated Systems Network ISO International Standards Organization ISPN INFO Security Product News ISPS Information System Production Systems ISS Initial System Sale or Internal Special Systems ISS Integrated Switching System ISSA Information Systems Security Association ISSM Information Systems Security Monitor ISSN Integrated Special Services Network ISU Integrated Service Unit ISUP Integrated Services User Part ISWS Internal Software Services IT Information Technology ITAP Information and Technology Architecture Plan ITAR International Traffic in Arms Regulation ITS Incompatible Time-Sharing System ITS Institute of Telecommunication Science ITS Internal Theft Syndicate ITSO Incoming Trunk Service Observation ITU Infinity Traders Unlimited ITU International Telecommunications Union IUD INC Utilities Division IVIS Interactive Video Interface System IVP Instant Virus Production IVP Installation Verification Program IVPC International Virus Prevention Conference IVTS International Video Teleconferencing Service IW Imperial Warlords IX Interactive Executive IXM Interexchange Mileage