BusinessPhone Communication Platform 4.0
System Description ASB 150 02

## System Capacity

Various types of limitations determine the maximum size and traffic capacity of the system.

### System size

#### Quantity of connected devices

The control system of the PBX is prepared to facilitate administration of 64 device boards. The physical reality (e.g. driving capacity of the busses) limits the capacity at present to a maximum of three cabinets with a total of 27 board positions.

The control system can handle a maximum of 128 devices on each board. Existing device boards have 4 to 108 devices per board.

Another limitation for how many devices can be handled is the available data memory in the central processor. (Each device requires a certain amount of space (volume) in the central memory).

Capacity with regard to telephone extensions and trunks is currently set to:

- a maximum of 300 extensions for hotel applications and 200 in business applications
- a maximum of 60 trunks

Furthermore, approximately 50 other devices type I/O-ports, register signalling units, voice message units can be connected.

#### Power supply for telephones

The maximum number of telephones that can be connected in one cabinet depends on the type of power supply used and the type(s) of telephone that are connected. The telephones consume different amounts of current, depending on telephone type and whether the telephone is off-hook or on-hook.

For more information see Installation Instruction (1531-BDV 113 08 Uen) and Installation Instruction (1531-BDV BS 101 01 Uen).

### Traffic capacity

#### Concurrent calls

The number of concurrent (simultaneous) calls is limited by the number of PCM-channels available in the system. For more information see section Switch.

A practical value is that 60 concurrent calls can be handled in the PBX when no other facilities are in use.

#### Calling rate

Almost all of the load on the PBX's control system is due to connecting/disconnecting calls in the PBX. During a call, the load on the control system is minimal. The maximum calling rate is determined by the capacity of the processors that control the system and of the communication link between these processors.

For the most complicated traffic cases, e.g. ACD, the system can handle at least one call every three seconds without any significant delay.

### Programmable data

#### Memory volume

The CPU-D4 offers in basic configuration 512 Kbytes of nonvolatile memory for programmable data. This can be increased in steps of 256 or 512 K up to 1024 Kbytes.

The greater part functions as a "bank" allocated by the various functions, depending on the number of device boards in the PBX and on how many functions are created by assigning data via commands.

The memory is dimensioned so that a normal PBX can be adequately supplied with functions, but it is not dimensioned for everything which, in theory, is possible to program in one and the same PBX.

#### Directory numbers

The system can store 1000 external directory numbers and 400 internal directory numbers. 80-100 numbers are utilised for permanently installed functions (facilities).

Revision: K © Ericsson Enterprise 2003