- I-Series recommendations ITU-TS (formerly the CCITT) recommendations on B-ISDN, ISDN and aspects of ATM.
- IAB (Internet Activities Board) The technical body that sets policy and standards for TCP/IP and the connected Internet suite of protocols. Its task forces are the IETF and IRTF.
- IBMCS (IBM Cabling System) Cabling system introduced by IBM in 1984 based around Shielded Twisted Pair (STP) cabling.
- ICCP Inter-Control Center Communications Protocol (IEC 60870-6 TASE.2)
- ICMP (Internet Control Message Protocol) Protocol allowing status messages to be generated by an internetworking gateway, indicating a variety of error or unusual conditions.
- ICR (Intelligent Character Recognition) Software similar to OCR, but it learns to recognize different fonts and character styles, so is more efficient. Useful to make paper documents accessible via groupware.
- IDA (Integrated Digital Access) The means of providing digital access for subscribers to the BT ISDN service. Two versions: single line IDA and multi-line IDA are available.
- IDAPI (Integrated Database Application Programming Interface) A standard from Borland and others providing a standard interface to a wide range of databases. It is supposed to be a superset of ODBC.
- IEC International Electrotechnical Commission
- IED Intelligent Electronic Device
- IEEE Institute of Electrical and Electronic Engineers: an international publishing and standards organization responsible for many LAN standards such as the 802 series.
- IEEE 802.2 The Data Link standard for use with IEEE 802.3, 802.4 and 802.5 standards. It specifies how the basic data connection should be set up over the cable.
- IEEE 802.3 The IEEE standardization of Ethernet. A Physical Layer definition that includes specification for physical cabling plus the method of transmitting data and controlling access to the cable. It uses the CSMA/CD access method on a bus topology LAN.
- IEEE 802.4 The IEEE standardization of Token Bus. A Physical Layer standard that uses the Token Ring passing access method on a bus topology LAN. Used by LANs implementing the Manufacturing Automation Protocol. The older Arcnet operates in a similar way but does not follow 802.4, but Arcnet supporters have been trying to get the technology ratified by IEEE without success.
- IEEE 802.5 The IEEE standardization of IBM Token Ring. A LAN Physical layer standard that uses the Token Ring passing access method on a ring topology LAN.
- IEEE 802.6 The standard that defines Mans, an SMDS-based, short packet ATM transmission.
- IGP (Interior Gateway Protocol) Term applied to any protocol used to propagate network reachability and routing information within an autonomous system. There is no single standard IGP, but RIP is one of the most common.
- IH intermediate hub
- IN (Intelligent Network) A sophisticated network capable of recognizing the profile (authorization, chosen services) of its users or subscribers. Carriers offering advanced services will increasingly offer IN services, particularly as the boundary between fixed and mobile networks becomes blurred.
- In-band signaling A communications technique in which the part of a signal bearing the data control information is contained within the bandwidth of the signal it is controlling.
- Installable file system A file system that can be installed in place of the usual file allocation table file system, such as the high-performance file system.
- Intelsat (International Telecommunications Satellite Organization) Founded in 1964 to develop a global satellite communications system, Intelsat has some 120 members, including- BT. The Earlybird (Intelsat 1) satellite was launched in 1965 as the first in a series. Intelsat VII is planned to replace the dozen aging Intelsat V-types which carry two-thirds of the world's telephone calls.
- Interface The place or piece of equipment where interaction occurs between two regions or systems or processes. A common example is the RS232-C port or the AUI on LANs between the computer and transceiver.
- Internet (1) A group of networks that are interconnected so that they appear to be one continuous network, and can be addressed seamlessly at the Network Layer Three of the OSI model. Typical internets are built using routers, either to form a backbone network comprised of routers, or to link together LANs at the Network Layer.
- Internet (2) A collection of networks and gateways, including the Milnet and NSFNET, all using the TCP/IP protocol suite. It functions as a single, cooperative virtual network. The Internet provides universal connectivity and three levels of network services: connectionless packet delivery; full duplex stream delivery and application level services including electronic mail and EDI.
- Internet address An IP address assigned in blocks of numbers to user organizations accessing the Internet by the US DoD's Network Information Center. Duplicate addresses can cause major headaches on the network, but the NIC trusts organizations to use individual addresses responsibly. Each address is an eight- bit number (0 to 255). There are three classes: A, B and C, depending on how many computers on the site are likely to be connected. The NIC is running out of Class B addresses, so work is in progress to extend the address format to allow expansion into the next century.
- Inter-Process Communications (IPC) Communications between several programs based on one computer or across a number of machines. Alternatively, communication across a network between different processes of the same program between different computers running parts of a single program, or between two programs working together. The most common approaches to IPC in networking circles are probably Application Programming Interfaces such as APPC and NetBios.
- IGP (Interior Gateway Protocol) The term applied to any protocol used to propagate network reachability and routing information within an autonomous system. There is no single standard IGP, but RIP is one of the most common.
- ICMP (Internet Control Message Protocol) An integral part of the Internet Protocol (IP) that handles error and control messages. ICMP also includes an echo request/reply used to test whether a destination is reachable and responding.
- IESG (Internet Engineering Steering Group) A US committee consisting of the IETF chairperson and the six area managers. The IESG coordinates activities among the IETF working groups.
- IETF (Internet Engineering Task Force) A US committee concerned with short-term and medium-term problems with TCP/IP and the connected Internet. The IETF is divided into six areas which are further divided into working groups and its chairperson is a member of the TAB.
- Interoperability The ability to exchange information between two systems so that the information can be processed meaningfully.
- IP (Internet Protocol) The TCP/IP standard protocol that defines the IP datagram as the unit of information passed across an Internet and provides the basis for connectionless packet delivery service. IP includes the ICMP control and error message protocol as an integral part. It provides the functional equivalent of ISO OSI Network Services.
- IP address The 32-bit address assigned to hosts that want to participate in a TCP/IP Internet. IP datagram - The basic unit of information passed across a TCP/IP Internet.
- IPG inter-packet gap
- IRTF (Internet Research Task Force) A technical group working or problems related to TCP/IP and the connected Internet, The IRTF is divided into a set of research groups. The IRTF chairperson is a member of the IAB.
- ISA (Industry Standard Architecture) The 8/16-bit bus architecture originally developed by IBM and now standard in almost all PCs that use Intel's 8086 and 80X86 chips.
- ISDN (Integrated Services Digital Network) An approach to switched digital networking that can handle a range of digital voice, data and digital image transmission. It is intended to provide end-to-end, simultaneous handling of digitized voice and data traffic on the same digital links via integrated switches. There are different access channels, according to geographic location. These include Basic Rate Access (2 x 64Kbit/s 161 + 16Kbit/s) and Primary Rate Access (1.544 (US) and 2.048 Mbit/s (Europe). ISDN standards are defined in the ITU-TS's I-Series Recommendations.
- ISO International Organization for Standardization