Class 4 vs. Class 5 Softswitch: What’s the Difference?

Communication is the heart of any business, including working with people who aren’t in the office or even the same region. Whether this means remote workers, suppliers, clients, or customers — your business relies on phone systems that work without issue. Two types of softswitches are at the heart of reliable communication but often go unnoticed by users and even IT: class 4 and class 5 softswitches.

Differences Between Class 5 and Class 4 Softswitches

Class 5 switches manage local call routing and enable advanced features for end users, while class 4 soft switches route long-distance calls. Together, they work in the background to connect businesses and customers regardless of distance.

This post will explain both types of switches and how they provide high-quality services. Understanding them will better equip you to provide and maintain dependable communication services.

What is a Softswitch?

A softswitch is a software-based solution that replaces traditional hardware telephone switches. VoIP networks primarily use it to route calls, manage bandwidth, and provide sought-after services like call forwarding and voicemail. Let’s examine these two major classes of soft switches and how they work together to benefit the organization.

Class 4 vs. Class 5 Softswitches

Class 4 and class 5 softswitches are critical VoIP network components, enabling efficient call routing and management. How do these classes vary from each other? They work together to offer a complete communication solution. Let’s break down how:

• Class 4 softswitches handle long-distance calls and wholesale traffic, focusing on routing calls across large networks.
• Class 5 softswitches manage local call delivery and advanced features for end users.

For example, a call originating in one country may be routed by a class 4 softswitch to another country, where a class 5 softswitch takes over to deliver the call to the recipient. The following table further compares these two classes of softswitches.

Feature	Class 4 Softswitch	Class 5 Softswitch
Purpose	Long-distance call routing	End-user call management
Target Users	Wholesale carriers, large enterprises	Residential and small business users
Concurrent Capacity	High	Moderate
Features	Routing, protocol support, security	Call features, billing, authentication
Examples of Use Cases	International VoIP routing	Local VoIP service provision

Both softswitches enable service providers to deliver high-quality communication services while optimizing network performance and reducing operational costs.

How Do VoIP Softswitches Work?

Softswitches replace physical hardware, and these relatively new virtualized switches handle many of the same responsibilities. We’ll break down a high-level overview of how these switches work in the context of a phone call:

1. Call initiation: This overall process begins when a user initiates a call by dialing a number or selecting a contact. The cloud softphone or application sends a signaling message to the VoIP server to request a call connection.
2. Call routing: The VoIP server determines the best route to connect the call to the recipient. This step requires analyzing the dialed number, checking the availability of the recipient, and selecting the appropriate VoIP gateway or server to route the call.
3. Call connection establishment: Once call routing is complete, the VoIP server establishes a connection between the caller and the recipient. This involves sending signaling messages to both parties to negotiate the call parameters, such as codecs and media streams.
4. Media processing: Next, the VoIP platform and endpoints handle the media processing, which varies depending on the specific call. This step typically involves encoding and decoding the audio and video streams and ensuring clear, low-latency communication.
5. Call termination: The process ends when the caller or the recipient terminates the call. The VoIP application sends a signaling message to the VoIP server to terminate the call connection, and the server releases the resources allocated to the call.

Depending on the nature of the call, the above process can involve both class 4 and class 5 softswitches or only require class 5.

Diving Deeper: Class 4 Softswitch

A class 4 softswitch is a critical component in wholesale VoIP infrastructure, as it’s designed to manage and route high volumes of long-distance and international voice traffic. This class serves as the backbone of the telecommunications network, bridges the gap between carriers, and ensures seamless connectivity across long distances. So, let’s further break down its features and how it’s used.

Core Features

What features does a class 4 softswitch bring to the table? A few standout features are:

• Call routing allows you to control the path of incoming and outgoing calls. You can define rules to direct calls based on various criteria, such as caller ID, time of day, or call destination.
• Protocol Support: Class 4 softswitches can handle communication protocols like SIP, H.323, or MGCP. Supporting multiple protocols ensures compatibility with a wide range of devices and networks.
• Transcoding simply converts voice data from one codec (audio format) to another so that different devices or networks can communicate. The softswitch handles this conversion, ensuring each call uses the right audio format.
• Fraud Prevention: Preventing fraud relies on several tools and techniques designed to detect and prevent fraudulent activities like call tampering, unauthorized access, or toll fraud.
• A firewall monitors data passing through the telephony system and blocks threats, ensuring only safe, approved traffic gets through.
• Call Detail Records (CDRs) are detailed logs of all calls made through the system, including information such as caller ID, duration, destination, and cost. They are essential for billing, troubleshooting, and network analysis.

Class 4 Softswitch Use Cases

How are class 4 switches put to work? A few common use cases include:

• Telecom carriers: Large-scale carriers use class 4 soft switches to route international and intercontinental traffic between different networks.
• Wholesale VoIP providers: A critical function of class 4 switches is to allow VoIP services and smaller carriers to rely on other networks to manage traffic.
• Enterprise communication: Enterprises with operations across several countries or regions often use class 4 softswitches to efficiently connect regional offices.

For example, a VoIP provider offering wholesale services may route calls from the United States to Europe. Using a class 4 softswitch, the provider can select the most efficient and cost-effective route, ensuring minimal latency and high call quality across vast distances.

Diving Deeper: Class 5 Softswitch

A class 5 softswitch is designed to directly interface with end-users, enabling local calling and advanced communication features users have come to expect. This class of software is critical for delivering VoIP services at the end-user level by supporting a wide range of options, services, and multi-media communication. We’ll further explore this class to underscore how it varies from class 4.

Core Features

What features do class 5 softswitches bring to the table? A few standout capabilities include:

• End-user services: Class 5 softswitches offer advanced functionalities like call forwarding, voicemail, auto-attendant, caller ID, and video conferencing. These features enhance the user experience, which makes it equipped for individuals and businesses.
• Billing integration: A class 5 softswitch with billing integrations makes usage easy to understand. An ideal option supports flexible pricing models, including per-minute billing, subscriptions, or bundled services.
• Authentication and security: Security is critical, and the right softswitch ensures end-users have secure access through encryption and multi-factor authentication. You’ll protect user data and prevent unauthorized access to VoIP services.
• User management portals: Supports a broad range of services, from basic telephony to SMS and unified communications. They allow customization to meet the needs of different customer segments, such as residential users or call centers.

Use Cases

How do businesses use class 5 softswitches in reality? A few ways common use cases are:

• Bundled VoIP services: ISPs offering bundled VoIP services to residential and small business customers require class 5 softswitches for local call management and value-added features.
• UCaaS providers: Companies that deliver integrated voice, video, and messaging solutions use class 5 soft switches to enhance communication capabilities.
• Contact centers: Call centers leverage class 5 soft switches to efficiently manage customer interactions, including call queuing, IVR, and reporting.

For example, a small business needs a reliable VoIP solution for handling customer calls, internal communication, and video meetings. They’ll need a class 5 softswitch with features like call forwarding, auto-attendant, and seamless video conferencing.

How Do Class 4 and Class 5 Softswitch Work Together?

We’ve explored how a class 4 softswitch primarily handles long-distance routing between carriers while class 5 softswitches manage local and regional calls. How do these two classes work together in practice? Let’s say a long-distance call is initiated through a class 5 softswitch. The call begins within a class 5 and is routed to a class 4 softswitch to optimally reach its destination, which is then transferred back to a class 5 softswitch at the end location. Ultimately, these classes are not mutually exclusive but work together to provide the best possible service.

Team Up with Acrobits for Dependable Communication

Both classes of softswitches are essential for modern communications. Companies have relied on similar, hardware-based solutions to meet these needs — but now, software-based alternatives create cost-effective solutions that increase reliability and quality. If you offer a communication platform to end users, the partner you choose for infrastructure and soft switches plays a significant role in the overall quality of your service. Partnering with reputable, time-tested providers like Acrobits ensures a seamless experience for anyone using your services, whether they need local or long-distance services. Legacy services with hardware-based switches simply can’t compete with modern virtual switches. Is it time to step into modern communications and leave low-quality calls behind? Book a demo with Acrobits today to learn more about how our communication tools can help.