Glossary

Delta channel. On ISDN networks, the channel that carries control and signaling information at 16Kbps for BRI ISDN services or 64Kbps for PRI ISDN services.

An item of hardware, usually a metal ring shaped like the letter D. It may be used at the end of a leather or fabric strap, or may be secured to a surface with a metal or fabric strap.

A type of connector that connects computer peripherals. It contains rows of pins or sockets shaped like a sideways D. Common connectors are the DB-9 and DB-25.

In telecommunications, a wiring method where each telephone jack in a building is wired in series from the previous jack. Daisy chaining is not the preferred wiring method, since a break in the wiring would disable all jacks

The external current that, under specified biasing conditions, flows in a photo detector when there is no incident radiation.

An unused fiber; a fiber carrying no light. Common when extra fiber capacity is installed.

Distributed Antenna System

With respect to data transmission, the interface that is used by a modem to communicate with a computer.

The smallest unit of data sent over a network. A packet includes a header with addressing information, and the data itself.

The maximum rate (in bits per second or some multiple thereof) at which data is transmitted in a data transmission link. The data rate may or may not be equal to the baud rate.

A term used for twisted-pair cable that is used in networks to carry data signals. Data-grade media has a higher frequency rating than voice-grade media used in telephone wiring does. Data-grade cable is considered Category 3 or higher cable.

(1) The interface that electronic equipment uses to communicate with a modem or other serial device. This port is often called the computer

A unit of data larger than or equal to a packet. Generally it is self-contained and its delivery is not guaranteed.

Also known as D type/ D Sub/ D type Sub miniature
D type connectors are used as serial port connectors.

The D refers to the shape of the connector. A D9W connector for instance as you can see below means it is a 9 pin connection interface.

This connector also commonly comes as a 15 way or 25 way although can go up to a 72 way.

Standard 15-pin connector used with Ethernet transceiver cables.