Private Automatic Branch Exchange (PABX)
PABX is a phone system that is installed at the customer premise and whose basic function is to share a small number of incoming Analogue or Digital lines with many stations or extensions. You may also hear of Key Telephone system (KTS) and Electronic Modular Switching System (EMSS).
The PABX supports various features that help the productivity of a business. Back in the early 1990's it was common install a pabx that included DISA (Direct Inward System Access), Caller ID, Voicemail, Doorphone, Door opener, Music on hold and External paging for announcements. The operator would use something that was called the attandant console. The SMDR (Station Message data recorder) output was printed via a serial printer that gave details of all calls made by individual extensions. Each extension had a class of service that defined the toll restriction level and other features such as executive over ride, conference calls, call forward, do not disturb etc. PABX's were normally wall mounted or floor mounted.
These days the PABX's are much smarter. You no longer require a line access code such as 9 or 1 to dial out on most PABX's as the switch is smart enough to read and understand the first 3 or 4 digits and know if the call is internal or external. PABX's are generally rack mounted and are connected to extensions via UTP (Unshielded Twisted Pair) cables, Voice and Data can share cables saving cost. PABX's these days support a wide range of features and services. You can connect PSTN, Centrex, ISDN, or SIP trunks and have Digital, Analogue, IP, DECT, Remote or mobile extensions. You can configure incoming calls to be answered by an Automated attadant or IVR and route calls automatically to hunt groups or individual extensions. Calls to extensions can be set up to ring the desktop phone and the mobile phone simultaneously and can be answered from either phone. Every extension can be assigned a mailbox for unanswered calls that can send notification by MWI or email. Mailbox can be accessed remotely. Calls can also be directed automatically to specific extensions based on the incoming caller ID. Extensions can also be assigned DDI numbers so that callers can directly reach the required extension. PABX's have Bi- direction SMDR and CTI integration and hence can integrate with 3rd party CRM, call centre softwares, and billing softwares.
The PABX supports various features that help the productivity of a business. Back in the early 1990's it was common install a pabx that included DISA (Direct Inward System Access), Caller ID, Voicemail, Doorphone, Door opener, Music on hold and External paging for announcements. The operator would use something that was called the attandant console. The SMDR (Station Message data recorder) output was printed via a serial printer that gave details of all calls made by individual extensions. Each extension had a class of service that defined the toll restriction level and other features such as executive over ride, conference calls, call forward, do not disturb etc. PABX's were normally wall mounted or floor mounted.
These days the PABX's are much smarter. You no longer require a line access code such as 9 or 1 to dial out on most PABX's as the switch is smart enough to read and understand the first 3 or 4 digits and know if the call is internal or external. PABX's are generally rack mounted and are connected to extensions via UTP (Unshielded Twisted Pair) cables, Voice and Data can share cables saving cost. PABX's these days support a wide range of features and services. You can connect PSTN, Centrex, ISDN, or SIP trunks and have Digital, Analogue, IP, DECT, Remote or mobile extensions. You can configure incoming calls to be answered by an Automated attadant or IVR and route calls automatically to hunt groups or individual extensions. Calls to extensions can be set up to ring the desktop phone and the mobile phone simultaneously and can be answered from either phone. Every extension can be assigned a mailbox for unanswered calls that can send notification by MWI or email. Mailbox can be accessed remotely. Calls can also be directed automatically to specific extensions based on the incoming caller ID. Extensions can also be assigned DDI numbers so that callers can directly reach the required extension. PABX's have Bi- direction SMDR and CTI integration and hence can integrate with 3rd party CRM, call centre softwares, and billing softwares.