Difference between Class 4 Softswitch and Class 5 Softswitch

Difference between Class 4 Softswitch and Class 5 Softswitch

Today, there is no issue with connectivity, thanks to the Internet. We can virtually communicate with people associated with our business anytime, anywhere using VoIP software and solutions. There are certain key points that help pick the right Softswitch solutions for your business. In this blog, we are talking about the difference between class 4 and class 5 Softswitch.

VoIP and the telecom industry are thriving as technological advancements. They have brought a radical change in business communication methods. When we talk about VoIP technology, a buzzword that comes to our mind is VoIP Softswitch

As per the Grand View Research report, the VoIP market size is expected to reach $145 B by 2024.

Let’s understand what a Softswitch is, its types, how they work, and what is the difference.

What is a Softswitch?

A Softswitch is a short form for a software switchboard. It is a central device or a type of software that routes or connects telephone calls virtually from one line to another across a telecom network or the public internet with the help of software running on a general-purpose computer system or a server. 

In short, it is a software-based device that virtually and automatically connects the calls using general-purpose servers and VoIP technology.

How does VoIP Softswitch work?

It receives calls made to phone numbers that fall under its network from traditional PSTN (Public Switched Telephone Network) networks. It is called origination in which calls made to numbers within the VoIP network originate in the PSTN network. 

The key role of VoIP Softswitch

Mainly it is to route calls that originate from its VoIP network to phone numbers in traditional PSTN networks. It is referred to as call termination in which calls made within the VoIP network are ended in a traditional PSTN network.

Based on the traditional functions in PSTN, VoIP SoftSwitches can be divided into two classes – Class 4 Softswitches and Class 5 Softswitches

Class 4 Softswitch is for routing large volumes of long-distance VoIP calls across various countries, and Class 5 Softswitch is for routing calls in a city, town, state, or country.

What is a Class 4 Softswitch? 

Class 4 Softswitch is defined as a Softswitch used for routing IP-IP calls to distant international locations. It is useful for transiting VoIP traffic between carriers. It can route large volumes of traffic over and between different exchanges and LATAs (Local Access and Transport Areas). 

Let’s understand the function of a Class 4 Softswitch through a hypothetical situation: Suppose an end-user wants to initiate a call from Toronto to a Japanese PSTN number. It will route the call to the Japanese PSTN number when a wholesale VoIP service provider will receive the transfer order from a Class 5 Softswitch.

What is a Class 5 Softswitch?

A Class 5 Softswitch can route calls between end-users or consumers in relatively small areas as compared to a Class 4 Softswitch. When it comes to international call routing, Class 5 Softswitch passes their traffic to a Class 4 Softswitch. 

In our example of a call from Toronto to Japan PSTN number, the retail VoIP Softswitch solution provider will transfer the international calls to a wholesale VoIP service provider using Class 5 Softswitch. In other words, Class 5 Softswitch is a retail solution while Class 4 Softswitch is a wholesale solution. Class 5 Softswitch also offers a plethora of modern features for enterprises and residential office customers. Now comes the main difference.

The difference between Class 4 and Class 5 Softswitch

Class 4 Softswitch is meant for routing long-distance calls or say, international calls while Class 5 Softswitch is responsible for routing calls in the same city, state, or country.

Key features of Class 4 and Class 5 Softswitch

Class 5 Softswitch has below given user-centric features. 

  • Basic dial-tone 
  • Calling features
  • IP PBX features
  • Call center services
  • Calling card platform
  • QoS, Business Groups 
  • Social media usability 
  • IVR

Class 4 Softswitch has features such as, 

  • Protocol support and conversion 
  • Several concurrent calls 
  • Transcoding
  • Intelligent call routing 
  • Secured firewall

Services include

  • Class 5 Softswitch is a handy retail solution, while Class 4 Softswitch is a wholesale solution. 
  • A Class 4 switch is a central office telephone exchange used to interconnect local exchange carrier offices for establishing long-distance communications in the PSTN. Whereas, a Class 5 Softswitch is an exchange in the PSTN located at the local telephone company’s central office for serving the end-users. 

Targeted users

  • Class 5 Softswitches are designed to work with both VoIP service providers and end-users. 
  • Class 4 Softswitches are made to serve wholesale VoIP solution providers, carriers, and Telco operators.


  • Class 4 Softswitch can transfer a lot of calls. 
  • Class 5 Softswitch can manage only a small number of calls.

Routing Area

  • A Class 5 Softswitch can route calls to the IP or SIP address or a DID (Direct Inward Dialling) number of the end-users. 
  • A Class 4 Softswitch routes large volumes of long-distance VoIP calls across multiple IP networks.
Wrapping up

Together Class 4 and Class 5 Softswitches provide feature-rich, next-gen services for establishing seamless communication between numerous enterprises across the nations. 
At Ecosmob, our team of dedicated VoIP software developers offers custom VoIP Softswitch solutions at competitive costs. Know more about our VoIP Softswitch Software. If you have any queries then write us at sales@ecosmob.com 

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