September 29, 2023

PBX Science

PBX technology, IT information, DIY projects

What is PBX phone system?

What's PBX?

What is PBX phone system?


What is PBX phone system? PBX (Private Branch eXchange) is a telecom system/equipment that provide two main tasks:

  • PSTN connection: PBX provide a way to let telephone extensions connect the public switched telephone network (PSTN)
  • PBX provides internal communication, also act a brdige to let extension dial out, or receive imcoming calls.

What is PBX phone system?


How PBX to connect PSTN?

Analog trunk:

After Phone was invented, analog phone line was kept in phone system untill internet technology was introduced into phone system.

Anyalog trunk is a kind of physical exist, because one line of phone trunck (PSTN) depends on two copper wires, which is wrapped by insulation material individually.

Two two wire is also wraped together to form a standard phone cable . Hence, how many PSTN you want to use in your PBX, you have to connect same quantity of phone cables to the PBX.


Digital trunk:

As copper resource is not so rich in earth shell and telecom increased so much in past one hundred year,  the problem people worry was that the Eeath didn’t have enough copper to provide huaman society to produce copper wire for telecom industry.

Afterwards, a big revolution is that optical fiber mostly replace copper wire, which is benefit from digital and internet quick development in the world.

The phone signal was transmitted by analog electrical signal in the past, but now almost all Public Switched Telephone Networks use digital signal via optical fiber.

PBX just needs to connect one optical fiber, which could provide hundreds digital trunks.



What’s IP PBX?


IP PBX stands for Internet Protocol Private Branch Exchange.
It is a telephony system that uses IP data networks instead of traditional circuit-switched telephone networks to transmit voice and other communication services.

An IP PBX is similar to a traditional PBX system, but instead of connecting to the public switched telephone network (PSTN), it connects to the IP network.

It can handle and route voice, video, and text-based communication, such as email, instant messaging, and SMS.


IP PBX systems offer several benefits over traditional PBX systems, including lower costs, greater scalability, and more advanced features such as unified messaging, call recording, and automatic call distribution.

They also enable businesses to have a single communication infrastructure for all their offices, remote locations, and mobile workers, providing a seamless communication experience.


What is PBX phone system?


What is VoIP gateway?

A VoIP gateway is a device that converts voice and fax calls, in real-time, between the traditional public switched telephone network (PSTN) and an IP network.
It serves as a bridge between the circuit-switched network and the packet-switched network, allowing calls to be transmitted between different types of networks using different protocols.

VoIP gateways come in various forms, including hardware and software-based gateways.

Hardware-based gateways are physical devices that connect the PSTN to an IP network, while software-based gateways run on servers and use virtualization technologies to provide the same functionality.


VoIP gateways play an important role in enabling businesses to take advantage of the cost savings and flexibility offered by VoIP technology while still being able to communicate with traditional phone networks.

They also enable businesses to extend their communication capabilities to remote locations by connecting remote offices to their central communication system.


IP PBX Functions:

IP PBX could provide huge functions, but depend on hardware and software.

*Unlimited Extensions
* Unlimited Auto Attendants
* Unlimited Voicemail Boxes
* Cell Phone Integration
* Integrated/Overhead Paging (PA System)
* Remote Phones
* Advanced User Interface
* Extension Groups
* Auto Provisioning
* Extension Range Flexibility
* Caller ID Customization
* DID Direct Inward Dialing
* Find Me/Follow Me
* Time of Day Routing
* Extension Call Recording
* On the Fly 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 Diagnositcs
* 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
* Multiple Music on Hold
* 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



What companies provide IP PBX?

There are many companies that provide IP PBX solutions. Some of the popular ones include:

  1. Cisco
  2. Avaya
  3. Mitel
  4. Sangoma
  5. 3CX
  6. Grandstream
  7. Yeastar
  8. FreePBX
  9. Asterisk
  10. Panasonic

These companies offer a range of IP PBX solutions with different features, capacities, and pricing to meet the needs of different businesses.


Free IP-PBX solutions

If you have the knoweledge about computer, networking, Linux, you may build an Enterprise-class IP PBX with a PC or ARM device like Raspberr Pi.


How to Build an Enterprise-class Phone System?



PBX on Raspberry Pi

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