NEC Aspila Topaz
Panasonic KX-TDA100
Toshiba Strata CIX100
Whatever the make, a PBX unit is composed several standard components or parts.
Below is the break down of anatomy of a PBX :
- Main shelf or casing
This is the plastic cover that protects the internal components and wiring. - CPU or processor
This is the brain of the PBX that performs all the logic and switching. In some IP PBX, it also acts as the digital signal processor (DSP). - Card slots
For PBX that supports cards expansion, these are the empty slots for you to add more cards for more capacity or functionality. The slot interface is usually proprietary. - Cards
These are the modular cards which can be added to or removed from the PBX. Each card provides specialized function. However, most common PBX models has a card for phone extensions. - Power supply
This component provides the power to the whole PBX, namely the processor and cards. One aspect to pay attention to is that the power rating is enough for all the cards in the PBX.
With these knowledge and vocalbularies in place, it would be easier for you to understand details of PBX inner-workings later.