I - Symbol used to designate current.

IC - see Intermediate Cross Connect.

ICEA - Insulated Cable Engineers Association

ICS - IBM Cabling System

IDC - Insulation Displacement Contact/Connector

IDF - Intermediate Distribution Frame. Thisis usually located on each floor within a building. It is tied directly to the Main Distribution Frame via cables.

IEC - International Electrotechnical Commission

IEEE - Institute of Electrical and Electronics Engineers. A professional organization and standards body. The IEEE Project 802 is the group within IEEE responsible for LAN technology standards.

IEEE 802.1 - The IEEE standards committee defining High Level Interfaces, Network Management, Internetworking, and other issues common across LAN technologies.

IEEE 802.2 - The IEEE standards committee defining Logical Link Control (LLC).

IEEE 802.3 - The IEEE standards committee defining Ethernet networks.

IEEE 802.5 - The IEEE standards committee defining Token-Ring standards.

Impedance - A unit of measure, expressed in Ohms, of the total opposition (resistance, capacitance and inductance) offered to the flow of an alternating current.

Impedance Match - A condition where the impedance of a particular circuit cable or component is the same as the impedance of the circuit, cable, or device to which it is connected.

Impedance Matching Transformer - A transformer designed to match the impedance of one circuit to another.

Index of Refraction - The ratio of light velocity in a vacuum to its velocity in a given transmission medium.

Infrastructure, Telecommunications - A collection of those telecommunications components, excluding equipment, that together provide the basic support for the distribution of all information within a building or campus.

Interconnection - A connection scheme that provides for the direct connection of a cable to another cable or to an equipment cable without a patch cord or jumper.

Intermediate Cross Connect - A cross-connect between 1st level and 2nd level backbone cabling.

Injection Laser Diode - A semiconductor laser in which the lasing occurs at the junction of n-type and p-type semiconductor materials.

Insertion Loss - A measure of the attenuation of a device by determining the output of a system before and after the device is inserted into the system. For example, a connector causes insertion loss across the interconnection (in comparison to a continuous cable with no interconnection).

ISDN - Integrated Services Digital Network or It Still Does Nothing

ISO - International Standards Organization

Isolated Ground - A separate ground conductor which is insulated from the equipment or building ground.

Isolation - The ability of a circuit or component to reject interference.

Insulation - A material which is nonconductive to the flow of electrical current.

Interference - Undesirable signals which interfere with the normal operation of electronic equipment or electronic transmission.

Isochronous - Signals which are dependent on some uniform timing or carry their own timing information imbedded as part of the signal. Voice and video signals are isochronous signals, but data transfer is generally not.

ITU - International Telecommunications Union. An international organization that develops communications standards.