Telephony

Telephony gives immediate voice, fax and other data communication with the outside world. You and your organisation will have specific requirements (e.g. basic one-on-one landlines), want certain capabilities (a certain amount of bandwidth or number of lines) and need desired features (e.g. forwarding, caller IDs, recording, conference calling, call management), which are all determined by the telephony system – analogue, digital or VoIP.

Analogue Phones and Analogue Phone Systems

Traditional analogue phone signals come through single copper cables that run from a switchboard (which switches between different addresses or phone numbers) to your building. This line (aka POTS – Plain Old Telephone Service) therefore physically connects your phone system’s private branch exchange (PBX) to the phone company. Although analogue cables usually offer a single phone line, splicing them together creates several lines – but these all share the same phone number. Traditional analogue phone systems have their limitations, including a maximum of 8 lines, no more than 24 extensions and a bandwidth of 56k in total, which is why they suit voice calls only, though this can be extended with an ADSL filter. Occasionally experiencing security issues, fluctuating performance (because of bad weather and extreme temperatures), interference and noise intrusion, analogue lines are not without their faults. However, they do cater for basic needs/provide standard features, have relatively cheap installations and rentals, can give you multiple, independent phone lines (increasing costs), run broadband (with ADSL filters) and suit certain set-up restrictions. They could therefore be all your organisation can handle and in fact needs.

Digital Phones and Digital Phone Systems

Digital transmission technology uses digital signals and their binary codes (sequences of 1s and 0s) to transfer data to your device (e.g. phone) for conversion into the original signal. Rather than the transmission occurring solely through traditional, single copper cables as they do in analogue systems, digital systems also use Integrated Services for Digital Networks (ISDNs) and give a maximum 128 kbps.

Digital technology allows a great concentration of binary codes within the same space that analogue alternatives use, resulting in fewer faults, higher reliability and quality (reception and transmission), improved voice clarity, less interference/external noise, added security and a greater capacity. As digital PBXs are designed with a proprietary bus structure, digital systems allow added features (e.g. extensions, virtual auto attendants, music when on hold, transfers), so they give you greater flexibility. Digital installations and equipment (e.g. the required interface for voice conversion) usually cost more than analogue systems but they are always evolving and even provide the basis for other systems such as VoIP.