Difference Between PSTN and PBX

Business telephone systems are classified into two main categories of systems at the present; the Public Switched Telephone Network (PSTN) and the Private Branch Exchange (PBX). They are both forms of communication but there are some distinct differences between them, primarily in that they both allow for voice calls.

PSTN in its Full is referred to as the Public Switched Telephone Network, this is the network that connects all PSTN phones which are the landline phones. On the other hand, PBX or private branch exchange systems are private telephone systems that are in a company’s premises to handle the company’s internal calls and route external calls through trunk lines connected to the PSTN.

In this article the reader will learn about key differences between proximal and production networks in terms of technological platforms, ownership, functionality, scalability and pricing. We will also look at when PSTN or PBX would be ideal for an organization, the size of business, and traffic intensity.

A connective network of lines and stations for phones that provides the modality for phoning and exchanging voice traffic. A massive meshwork that encases the world where people across the world can communicate with the other. It formed the very basis of phone tech and is still functioning as a crucial life wire of the modern telecoms industry.

1. Analog and Digital Signals: PSTN initially relied on analog signals but has increasingly shifted to digital signals for improved clarity and capacity. Analog signals are converted to digital form using codecs.

2. Circuit Switching: When a call is made, a dedicated circuit is established between the caller and the receiver for the duration of the call. This ensures a consistent and clear communication channel.

3. Network Components:

• Local Loop: The connection from the subscriber’s home or office to the local exchange.
• Central Office (CO): Local exchanges that connect subscriber lines to the PSTN.
• Trunks: High-capacity transmission lines that connect different exchanges.
• Switches: Devices that establish and manage the connections between different parts of the network.

4. Call Setup: When a call is initiated, the signaling system (such as SS7) is used to find a path through the network, establish the circuit, and alert the receiving party.

5. Maintenance and Operation: PSTN is maintained by telecom providers who ensure that the infrastructure is functioning optimally and can handle the volume of calls.

Private Branch Exchange (PBX):

A kind of central exchange A PBX is a mediation system that oversees the waltz of calls within an office or a firm. It also works as a gatekeeper, directing the rings to the necessary desks and provides reduced access to the outside line for the staffers. This clever box can also perform a whole host of other stunts, including voice mail, on-call options, and a multitude of conferences. In other words, a PBX is the overall director that synchronizes the social buzz of a workplace, in effect, coordinating the humming.

1. Internal Switching: PBX systems manage internal calls within an organization without routing them through the PSTN. This is done using internal switches that connect different extensions directly.

2. Call Routing: PBX can route incoming and outgoing calls. For external calls, the PBX connects to the PSTN or a VoIP provider. For internal calls, it switches the call directly to the appropriate extension.

3. Features and Functions:

• Automated Attendant: Answers calls and routes them to the appropriate department or extension.
• Voicemail: Provides voice message services for missed calls.
• Call Forwarding: Redirects calls to another number or extension.
• Conferencing: Facilitates multi-party calls.
• Interactive Voice Response (IVR): Allows callers to interact with an automated system using voice or keypad inputs.

4. Types of PBX:

• Traditional PBX: Uses dedicated hardware installed on-premises.
• IP PBX: Uses internet protocol to route calls and can be either on-premises or cloud-based.
• Hosted PBX: A service provided by a third party where the PBX is hosted off-site and accessed via the internet.

5. Integration with Other Systems: Modern PBX systems can integrate with other communication tools like email, instant messaging, and CRM systems, providing a unified communication platform.

What are the perks of PSTN?

PSTN offers wide access to any phone line worldwide. It’s kept up by experts and has strong safety rules. Yet, it can be dear for big firms with lots of calls.

What are the advantages of PBX?

PBX gives more tools for call routing, voicemail, and add-ons. Calls within the firm are free. It also costs less for firms with high call volumes. But setup and upkeep can be complex.