Decide how much internal room to work in your office. To calculate the required number, proceed from the number of employees. Don't forget to take into account internal number for Fax and other office purposes. Determine the number of external lines will be able to ensure the smooth operation of the office. In the case of using your phone number as a hotline number of outside lines should correspond to the size of the region that you are working with, and the number of staff involved in processing calls.
Connect the required number of lines. It should not be less than the required number of incoming lines. If you are connected to the main telephone line, extend it with more. For this you should contact the company that provides your office telephone. After the service of the carrier will check your communication and confirm the technical feasibility for the necessary connections, your office will be able to hold an additional line.
Buy office PBX, the model which meets your needs. If this ATS is not the sale, get that one, which later can be expanded to the desired modification. This is done using a special expansion card that will also need to purchase.
Contact the engineer who is engaged in the PBX. He needs to install expansion boards in the station, connect the telephone line to the PBX and program the station. In order to have guarantees of quality work, invite a specialist from the outside and from the phone company, whose services you use. Most likely, the call the engineer will be paid.
Organize digital channel if the PBX may not provide the required number of internal and external rooms. This service can provide the provider. Make a diagram of the call and shall describe the location of the phones of employees.