I

IAB (Internet Activities Board) The technical body that oversees the development of the Internet suite of protocols.

ICMP (Internet Control Message Protocol) (TCP/IP) The collection of messages exchanged by IP modules in both hosts and gateways to report errors, problems and operating information.

IDRP (Interdomain Routing Protocol) OSI protocol that controls how routers in different domains communicate with each other.

IEEE (Institute of Electrical and Electronics Engineers) Committees that develop and propose computer standards, such as the 802 protocols, which define the physical and data link protocols of communication networks. Members represent an international cross section of users, vendors and engineering professionals.

IETF Internet Engineering Task Force

IGP (Interior Gateway Protocol) The protocol used to exchange routing information between collaborating routers in the Internet. RIP and OSPF are examples of IGPs.

ILMI Interim Local Management Interface. An interim requirements definition in ATM Forum UNI 3.1. It supports bidirectional exchange of management information between UNI Management Entities related to the ATM layer and physical layer parameters.

IMAP Interactive Mail Access Protocol. A more sophisticated version of POP which adds more mailbox capabilities. Defined in RFC1203.

IMS Interprocessor Messaging System in 3Coms Multi- Processor Architecture

Input packet filtering Filtering applied to packets immediately upon reaching the router, before they reach the router's internal forwarding processing. Since the packets never enter the router, the router itself is protected against an external attack.

Integrated IS-IS Routing protocol based on the OSI routing protocol IS- IS, but with support for IP or other networks. Integrated IS-IS implementations send only one set of routing updates and are more efficient than two separate implementations.

Interactive Video (IV) A computer linked by software to a video system which allows the user control of a video disc and view the information on it.

Interexchange carrier (IXC) A long-distance telephone company offering circuit- switched, leased-line or packet-switched service or some combination.

InterLata InterLata are connections between local access companies, i.e., long distance connections.

internet (lower case i) An internet is any collection of two or more connected networks.

Internet (upper case I) The vast collection of connected networks (ie an "internet"), comprising large backbone nets (MILNET, NSFNET and CREN for example) and an array of regional and local campus networks worldwide. All of which uses the TCP/IP protocol suite.

Internet Address (See IP Address)

Internetwork Series of networks interconnected by routers or other devices that functions as a single network. Sometimes called an internet, which is not synonymous with the Internet.

Intranet A private network that is solely for the use of it's owners.

Inverse multiplexing The logical aggregation of multiple switched circuits to achieve a higher effective transmission speed.

IOPS Input/Output (operations or requests) per second

IP (Internet Protocol) (TCP/IP) The standard for sending the basic unit of data, an IP datagram, through an internet.

IP Address The unique set of four numbers, in the range 1 - 254 (eg. 128.138.136.181), by which every host machine on the Internet is identified.

IP/RIP Internet Protocol/Routing Internet Protocol.

IP spoofing The use of a forged IP source address to circumvent a firewall. The packet appears to have come from inside the protected network and to be eligible for forwarding into the network.

IPX (Internetwork Packet Exchange, Network Protocol) LAN protocol developed by Novell for NetWare*.

IRC Internet Relay Chat - allows multiple users to send messages to all other participating users in real time.

IS (Intermediate System) A bridge, router, gateway or hub that interconnects network segments.

ISDN (Integrated Services Digital Network) The recommendation published by CCITT for private or public digital telephone networks where binary data, such as graphics and digitized voice and data transmission, pass over the same digital network that carries most telephone transmissions today.

IS Information Systems department in corporations

ISA Industry Standard Architecture

ISE Internet Switching Engine

IS-IS (Intermediate System to Intermediate System (OSI protocol) The OSI protocol by which intermediate systems exchange routing information.

ISO International Standards Organisation.

ISP Internet Service Provider.

ITU-TSS International Telecommunications Union Standardization Sector

ITU International Telephone Union

IXC (See Interexchange Carrier)