Combined distribution frame
Encyclopedia
In telecommunication
, a combined distribution frame (CDF) is a distribution frame
that combines the functions of main
and intermediate distribution frame
s and contains both vertical and horizontal terminating blocks.
The vertical blocks are used to terminate the permanent outside lines entering the station. Horizontal blocks are used to terminate inside plant
equipment. This arrangement permits the association of any outside line
with any desired terminal equipment
. These connections are made either with twisted pair wire, normally referred to as jumper wire, or with optical fiber
cables, normally referred to as jumper cables.
In technical control facilities, the vertical side may be used to terminate equipment as well as outside lines. The horizontal side is then used for jackfields and battery terminations.
Telecommunication
Telecommunication is the transmission of information over significant distances to communicate. In earlier times, telecommunications involved the use of visual signals, such as beacons, smoke signals, semaphore telegraphs, signal flags, and optical heliographs, or audio messages via coded...
, a combined distribution frame (CDF) is a distribution frame
Distribution frame
In telecommunications, a distribution frame is a passive device which terminates cables, allowing arbitrary interconnections to be made.For example, the Main Distribution Frame located at a telephone central office terminates the cables leading to subscribers on the one hand, and cables leading to...
that combines the functions of main
Main distribution frame
In telephony, a main distribution frame is a signal distribution frame for connecting equipment to cables and subscriber carrier equipment . The MDF is a termination point within the local telephone exchange where exchange equipment and terminations of local loops are connected by jumper wires...
and intermediate distribution frame
Intermediate distribution frame
Intermediate distribution frame : In a central office or customer premises, a frame that cross-connects the user cable media to individual user line circuits and may serve as a distribution point for multipair cables from the main distribution frame or combined distribution frame to individual...
s and contains both vertical and horizontal terminating blocks.
The vertical blocks are used to terminate the permanent outside lines entering the station. Horizontal blocks are used to terminate inside plant
Inside plant
In telecommunication, the term inside plant has the following meanings:*All the cabling and equipment installed in a telecommunications facility, including the main distribution frame and all the equipment extending inward therefrom, such as PABX or central office equipment, MDF heat coil...
equipment. This arrangement permits the association of any outside line
Telephone line
A telephone line or telephone circuit is a single-user circuit on a telephone communication system...
with any desired terminal equipment
Terminal equipment
In telecommunication, the term terminal equipment has the following meanings:* Communications equipment at either end of a communications link, used to permit the stations involved to accomplish the mission for which the link was established....
. These connections are made either with twisted pair wire, normally referred to as jumper wire, or with optical fiber
Optical fiber
An optical fiber is a flexible, transparent fiber made of a pure glass not much wider than a human hair. It functions as a waveguide, or "light pipe", to transmit light between the two ends of the fiber. The field of applied science and engineering concerned with the design and application of...
cables, normally referred to as jumper cables.
In technical control facilities, the vertical side may be used to terminate equipment as well as outside lines. The horizontal side is then used for jackfields and battery terminations.