The Difference Between Class 4 and Class 5 Softswitch

Class 4 Softswitch vs Class 5 Softswtich

VoIP industry is passing through a revolutionary time with new developments in the IP Communications arena.  A study shows that the global Mobile VoIP market is expected to reach USD 145.76 billion which is up to 28% by 2024! Nowadays many young entrepreneurs are getting into VoIP business owing to the boom in this field. As a new entrant, when you are entering this the VoIP arena, you should be familiar with the various types of terminologies such as Softswitch, Mobile Dialer, VoIP Billing, Mobile OTT etc. In this blog, we will discuss about Softswitch and its types, which works as a middle device for initiating and routing any call through telecommunication network.

What is a Softswitch

A softswitch is a software used in the telecommunication network for launching, maintaining, routing and terminating sessions in Voice over IP (VoIP) networks. Internet-based telephony and a growing number of traditional telecommunication networks use this  software switch to manage the connection of phone calls.

Call switching in the telecommunication industry is a long-term practice to interface the caller to the intended recipient. It was a manual process earlier when the phone administrators shifted the phone line physically, starting with one circuit then onto the next, to interface the call between a caller and recipient. In the present scenario, if you notice a typical VoIP Architecture, the manual call routing had moved on to an automated process with the help of a softswitch.

This software consequently switches the phone lines, and it is a mix of a software and switchboard. It has the programmed logic to play out this telephone line exchanging. Class 4 and Class 5 Switch are the most widely used switch for routing calls through different networks. This Blog will inform you these specialized terms and the distinction between the both.

Class 5 Softswitch

Class 5 Softswitch is a strong platform with lots of interesting modern features. Through this software, a retail VoIP service provider can provide extremely rich quality IP services to enterprise and residential office customers with IP enabled devices like land-line IP phones and adaptors!.

So, if an enduser wants to make a call from Singapore to Japan PSTN number, what’s the role of Class 5 Softswitch? To begin with, the call controlled by retail VoIP solution provider will be transmitted to a wholesale VoIP provider via Class 5 Switch. What happens after it reaches the wholesale VoIP provider is explained below. In addition this type of platform contains many modern features like social media access for a user-friendly experience.

Class 4 Softswitch

Class 4 Softswitch is mainly used for routing IP-IP calls to long distant international locations using an IP network. For example, if an end user wants to initiate a call from Singapore to Japanese PSTN number,  Class 4 Switch will route the call to Japanese PSTN number only when a wholesale VoIP service provider receives the transfer order from a Class 5 Switch.

In addition, Class 4 Softswitch, which has less features than Class 5, enables cost-efficient scaling of voice services while offering a reliable presence between inter exchange carriers.

Major Differences:

No doubt, Class 5 and Class 4  switch both are complete VoIP solutions that roll out rich in featuring next generation services! But, you also need to understand some major differences between the two:


Class 5 Softswitch is responsible for transferring calls to Class 4 Softswitch after receiving the calls, within small areas, for long distance routing through retail VoIP service providers. After receiving calls from Class 5 Switch, a wholesale VoIP service provider routes the call to the long destination by the help of a Class 4 platform.

Features Count:

Class 5 Softswitch services include basic dial-tone, calling features, and additional digital and data services to subscribers using the local loop; but a Class 4 Softswitch is just a simplified solution. The main function of the Class 4 solution is the routing of large volumes of long distance VoIP calls paralleling with other Class 4 telephone switches.

Types of Service:

Class 5 Softswitch is more of a retail solution whereas, Class 4  is a wholesale solution. What does it mean? A Class 4 switch is a central office telephone exchange which is used to interconnect local exchange carrier offices, for long distance communications, in the public switched telephone network.

In contrast, a Class 5  Softswitch is a telephone switch or telephone exchange in the public switched telephone network, located at the local telephone company’s central office, directly serving end users.

Key Characteristics

The most important characteristics of Class 4 solution are,

  • Protocol support and conversion
  • Transcoding
  • Calls per second rate
  • Average time of one call routing
  • Number of concurrent calls
  • Flexible UI (user interface)
  • Intelligent call routing
  • Billing interface including CDR
  • Secured firewall
  • Filtered Third party routing engine

On the other hand, Class 5 Softswitch characteristics includes,

  • Call authentication
  • Billing and Routing
  • IVR
  • Callback
  • Analog-to-digital conversion
  • Support for Codec, Media transcoding
  • Social Media usability
  • Call transfer
  • Call holding
  • Call forking


Class 5 Softswitches are intended to work with both VoIP service providers as well as end users. This type of switch  platform is for local & long-distance telephony services, both. So, it possesses additional service features for end-users & corporate clients such as IP PBX features, call center services, calling card platform, types of authorization, QoS, Business Groups etc.

On the other hand, Class 4 platform intends to serve wholesale VoIP solution providers, PSTN, Telco Operators, carriers etc.


Class 4 Softswitch can transfer a large amount of call but Class 5 Switch solution can handle only small number of calls.

Route Area:

A Class 4 softswitch routes large volumes of usually long-distance VoIP calls throughout multiple IP network. In contrast, a Class 5 routes calls to the correct IP address, SIP address or DID number of an End user.


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REVE Systems

Reve Systems editorial team aims to keep readers informed about the latest ongoings in the telecom technology.
REVE Systems

  • Tanzeel Iqbal

    is iTel Mobile Dialer this system work with Asterisk freepbx, elastix?

    • Nujhatul Kubra


  • For delivering VoIP traffic and VoIP products over numerous IP Networks worldwide. We develop highly adaptable and better-performing freeswitch based Class 4 Softswitch. Hodusoft Class 4 Softswitch equips service providers with the sophisticated billing features to control costs and maximize revenue. HoduSwitch has latest features and functionality that gives user robust and reliable performance.

  • Alex Carson

    Such a informative article it is thank you for sharing

  • Ravi is a cloud-based Call Center Software Solution, equipped with enterprise-grade Communication abilities.

    Unify all business communication channels- web-chat, email, voice calls, SMS, and Social Media Channels within a dynamic & robust, centrally managed Customer Experience Management Platform.

  • Hamada Kamel Ali

    how i can Register a VoIP Service Provider & have your own IP Soft Switch.

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  • Ravi is a Contact Center Solution equipped with enterprise-grade communication abilities. unifies all business communication platforms – web-chat, email, voice calls, SMS, and Social Media Channels within a dynamic & robust, centrally managed Customer Experience Management Platform. is Call Center Software that supports both inbound and outbound communication processes seamlessly.

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