Connectivity of telephone network architecture

connectivity of telephone network architecture

   

  

   MAIN DISTRIBUTION FRAME (MDF)

- main cross connection point between the Outside Plant (OSP) cable pairs and the exchange.

- it provides a great flexibility for line testing functions as well as electrical protection. Used for line     terminations.

   MAN HOLE

- a jointing chamber / breakout point of cables which one man can get down to the man hole and can     do the repairs.

- called feeder cables (large bundles) of twisted pair cable (from 50- 3000 pairs) are then taken to the    underground and then trough manholes to a cabinet,where they are terminated again.

CABINET 

- termination between the underground cables are coming from the MDF and distribution point (DP)     side.

- consists of two sides called primary and secondary.

- primary side from MDF

secondary side from DP

DISTRIBUTION POINT (DP)

- termination point between cabinet and the subcriber.

- each DP contains 10 subcribers

- drop wire is connected to the subcriber premises through the discharger unit.

-purpose of discharger unit is to protect the telephone set of the subcriber from lightning damages.     This uses the fuses and arrestors.

OVERHEAD WIRE

- suspended above the ground using poles.

- wire extended from underground cable and suspended above the ground and connected to the               distribution point.

DROP WIRE

- an aboveground or underground line or wire which connects the terminal of a distribution cable to a    subcriber's premises.

- consits of a telephone wire ( 1 pair of copper wire).

UNDERGROUND CABLE

- consists one or more conductors covered with suitable insulation and surrounded by a protecting        cover.

- the conducter used in cable should be tinned stranded copper or aluminium of high conductuvity.

- the cable must have the proper thickness.