Company PBX

Company PBX is a Private Branch Exchange that serves the communication needs of a given business or office. It can also be called as PABX - Private Automatic Branch Exchange. It differs from key systems in line selection since in case of key systems user manually select outgoing lines, but with PBX outgoing lines are selected automatically. However, hybrid systems that are able to combine both features already exist.

PBX functions as a switch station for telephone systems. It has several branches of telephone systems and it switches connections to and from them in this way linking telephone lines. In other words, PBX connects internal phones of an organization together and also connects these phones to the PSTN (Public Switched Telephone Network) over trunk lines (Figure 1).

a company pbx connects the company telephone system to the pstn
Figure 1 - A company PBX connects the company telephone system to the PSTN

In this way all internal line are connected to an external line meaning that only one line is leased but many people can use this one line for making calls. Each of the users has a telephone at the desk and they have different phone numbers. These phone numbers depend on the internal numbering (they are not the same as regular phone numbers) since within the PBX users can reach each other in the network by dialing a three- or four-digit number.

These branches include telephones, fax machines, modems, etc that is why the end points of them are referred to as "extension". People calling from outside the network can ask for an extension in order to be directed to the target person.

What are the roles of a PBX?

PBX are to:

  • create connection by switching between users
  • ensure that the connection will be properly maintained while it keeps its resources
  • end the connection properly if one party hangs up
  • record all the parameters regarding to calls like quantities, statistics, etc.
  • provide information for accounting purposes

Beside these basic functions, several other features can be available by using PBXs. These additional features depend on the product you selected.

The most common functions:

  • Ensuring one number through which external calls can reach corporate users within PBX
  • Distributing calls to corporate users effectively
  • Automating call answering while it provides a menu of options that will allow users to select the respective extension or department
  • Customized business greetings
  • System call management
  • Call transfer between internal extensions
  • Auto attendant
  • Auto dialing
  • Automatic ring back
  • Call accounting
  • Call Blocking
  • Call forwarding on busy or absence
  • Call park
  • Call pick-up
  • Call transfer
  • Call waiting
  • Camp-on
  • Conference call
  • Custom greetings
  • Customized Abbreviated dialing (Speed Dialing)
  • Busy Override
  • Direct Inward Dialing
  • Do not disturb (DND)
  • Follow-me, find-me
  • Interactive voice response
  • Music on hold
  • Night service
  • Shared message boxes (where a department can have a shared voicemail box)
  • Voice mail
  • Voice message broadcasting
  • Voice paging (PA system)
  • Welcome Message, etc.

What you need to know about an IP-PBX

IP-PBX has been developed to meet the increasing requirements of companies. Since data networks were widespread and packet switching became well-known, companies needed packet switched networks for data and therefore using them for making calls over the Internet has become more attractive than ever. Today most modern PBX systems support VoIP (Voice over IP).

Until now PBX systems has been considered as luxury only affordable for larger companies. But with IP PBX even medium-sized and small companies can introduce PBX functions into their businesses by adopting VoIP. However, they need to spend some money on hardware and software but ROI (Return on Investment) will be considerably high especially in the long term both operationally and financially.

The major benefits of an IP-PBX system are scalability, manageability and further enhanced features. IP-PBX allows cost effective and easy addition or removal of users to and from the phone system. IP phones ensure the connection among users. It is not necessary for users to connect to only one IP phone meaning that users can easily log into the system via any phone of the network while keeping their personal configurations. IP PBX are relatively software based systems in this way maintenance and upgrade costs are reduced to a great extent and they are also easier to work with.

Main features of an IP-PBX


(Again depend on the service you use)

  • Unlimited Extensions
  • Unlimited Auto Attendants
  • Unlimited Voicemail Boxes
  • Cell Phone Integration
  • Integrated/Overhead Paging (PA System)
  • Remote Phones
  • Advanced User Interface (including Find me/Follow Me, Unified Messaging, Call recordings, Voicemail .wav).
  • Extension Groups
  • Caller ID Customization
  • DID Direct Inward Dialing
  • Extension Call Recording
  • Call Return
  • Voicemail Callback
  • Voicemail to Email
  • SMS Voicemail notification
  • Voicemail Web Access
  • Voicemail Bypass
  • Intuitive VoIP Ready
  • Voicemail Blast Groups
  • VoIP Ready
  • Inbound Call Description
  • VoIP Compression
  • Outlook Integration
  • Announcement Interface
  • Call-out
  • Call Pickup
  • System Diagnostics
  • Multivendor Phone Options
  • Analog Phone Support
  • BYO Phones
  • Call Parking
  • Call Barge
  • Dial by Name Directory
  • Powerful Reporting
  • CRM Integration
  • Remote Linked Servers
  • Operator Console
  • Custom Routing Rules
  • Conference Rooms
  • Outbound Dial Map
  • Speed Dial Numbers
  • Channel Bank Support
  • Analog and Digital T1 Ready
  • PSTN or Digital Failover
  • NIS Routing
  • Advanced Routing (IVR)
  • Fast Pass
  • Caller Position Notification
  • Call Whisper
  • Auto call forwarding
  • Unified Messaging
  • Call Screening
  • ANI Routing
  • DNIS Routing
  • Enhanced Mobility
  • Custom VoIP Provider
  • Professional Development
  • Fax Support
  • Fax to Email
  • Fax PDF Support
  • ACD Features
  • Click to Dial
  • Softphone
  • Call Transfer
  • Call Conference
  • Live Monitoring, etc.

Related Pages

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