In modern business communication, SIP trunking has become an inevitable tool for streamlining an organization’s voice services.
Compared with traditional voice communication using telephone lines, SIP calling software offers more flexible and cost-effective real-time communication.
“According to research, the SIP communication can save up to 75% on communication costs and 40% better quality than traditional systems.”
However, it’ll be overwhelming to utilize the necessary features if you end up with the SIP calling software that doesn’t fit your needs.
The next constraint that will follow is the integration of the existing websites or apps.
Don’t worry. This blog will help you save from off the track by providing a detailed comparison and review of the top custom SIP and VoIP calling software for 2025.
Table of Contents
What is SIP Calling Software?
SIP (Session Initiation Protocol) calling software allows you to make and receive phone calls using VoIP over the Internet. The SIP trunking software often uses VoIP to transform your analog call traffic over an internet connection.
Imagine you’re proceeding a video call with your colleague using your laptop. You’re using the Internet to connect and establish a connection.
Now, imagine you’re using the same internet connection to make regular phone calls; that’s essentially what SIP calling is.
Key Features to Look for in VoIP Calling Software
Choosing the best SIP software can be tagged easily but to integrate into your business environment it requires factors to consider. Let’s see the key features to look for in a SIP trunk provider.
1. The Reliability
If your business is going to offer customer service to resolve their queries shouldn’t look for another resolver in terms of connection. Look for an in-app SIP trunk provider who will offer a reliable SIP connection with zero downtime.
This will ensure your communication is smooth for both internal and external conversations.
2. The Scalability
Don’t limit your SIP app’s usage based on your current requirements. Look for a scalable SIP call solution to extend the functionality based on fluctuating demands.
Considering the scalability in this stage while choosing the VoIP calling software helps to manage the cost effectively without compromising service quality.
3. Global Coverage
If you’re operating your company internationally, ensure that your VoIP provider offers global coverage. Be active to check whether it includes supporting local numbers, zero downtime, and crystal clear voice quality in multiple countries.
4. The Customizations
Businesses nowadays don’t consider customizations as the main aspect. Sadly, many don’t know there are custom SIP voice call providers out there; let them customize the features and add branding elements to make it more credible. So, build your VoIP calling app with the customization options.
How Does SIP Calling Software Work for Voice Calls
Session Initiation Protocol (SIP) is a sophisticated communication technology that supports simultaneous interactions in various communication sessions.
Here’s the more detailed breakdown of SIP and VoIP calling process:
- Conversion: The first step in the SIP calling process is conversion, where your phone or computer converts your voice into a digital data packet from analog to digital.
- Packet Formation & Transmission: These digital data are later encapsulated within SIP signaling, where all the information about the call will be stored, such as the caller’s and recipient’s phone numbers, the call type (voice or video) and the quality of the service.
- SIP Server Interaction: Another major component is the SIP server, which manages the call. The SIP agent on your mobile or computer sends the SIP signaling packets to the SIP server, which acts as a central hub and routes them to the desired destination.
- Routing: The SIP server utilizes its routing algorithm to find the best path for the call based on network congestion, call quality and cost. Later, it sends the SIP signaling packets to the recipient’s SIP server.
- Session Establishment: The recipient’s SIP server receives the SIP signaling packet from the sender and determines if the receiver is available to attend to the call. If the recipient is available, the SIP server establishes a session.
Top 7 SIP & VOIP Calling Software for Businesses in 2025
The best SIP and VoIP calling software providers are MirrorFly, ApphiTect, RingCentral, Grasshopper, Virtual PBX, CallRail, and Cisco VoIP.
1️⃣ MirrorFly
(Custom SIP Calling for Banking and Enterprises)
MirrorFly is a leading communication solution provider for the brands across the globe by facilitating white label in-app chat APIs and SDKs. MirrorFly SIP functionality can be scalable with a global infrastructure that supports 1 billion concurrent conversations and multilingual languages.
With developer friendly SIP calling APIs you can build VoIP calling app for your business with extensive customization options.
Also, MirrorFly supports fast and easy integration and custom security protocols with end-to-end encryption. MirrorFly ensures the ultra low latency communication supports 99.999% uptime SLA.
Key Features of MirrorFly SIP Calling Software
- Unlimited SIP/VoIP calls
- 1:1 voice call
- Unlimited group calls
- Multi-tenancy support
- 100% customizable APIs and SDKs
- One-time license fee
- Dedicated development team and support
- Free migration
2️⃣ ApphiTect
(UAE’s Leading In-App VoIP Calling Software Provider)
Apphitect is an UAE-based SIP voice calling software solution that offers self-hosted APIs and SDKs for both Android and iOS.
Apphitect includes real-time voice and chat functionality, as well as advanced customization options. Users can tailor each function and branding based on enterprise requirements, such as adding a logo, brand color, and fonts.
Apphitect VoIP calling software enables 100+ third-party integrations and is flexible to scale up with multi-faceted features.
3️⃣ RingCentral
RingCentral is a programmable voice API that aims to improve both internal and customer-business communication. This VoIP platform supports personalized interactions through text messages and phone calls across any channel and to build custom VoIP calling apps.
With easy customization and integration options, developers can easily integrate voice chat functionalities for regular phone calls which will cover their internal communications too, however, accompanied by certain limitations.
4️⃣ Grasshopper
Grasshopper VoIP call software is more than just making phone calls; it allows you to lead the customer-business discussion and provide a better experience. Grasshopper allows you to personalize WebRTC and PSTN based on user context and business requirements.
It has a wide range of applications, including healthcare, education, retail, banking, logistics, and travel SIP calls.
5️⃣ Virtual PBX
The Virtual PBX voice communication system provides high-quality SIP audio calls with well-managed infrastructure to support large numbers of talks. This platform supports personal and private group calls while also providing a high level of security.
With a highly dependable chat platform infrastructure that provides scalable and engaging calling experiences. Still, the pricing structure may not be appropriate for small firms or startups. Before selecting this SIP software, it is suggested that you conduct a full pricing study.
6️⃣ CallRail
CallRail is loaded with SIP features that’s beyond voice calls. With this VoIP calling software you can track your business calls for better outcomes.
CallRail is best for marketing and enterprise campaign communications to make sales calls then it can be converted into measurable data using AI for analytics.
7️⃣ Cisco VoIP
Cisco VoIP offers a comprehensive chat and voice integration solution with a wide range of carrier network connections. As a worldwide SIP provider, Cisco VoIP software provides seamless connectivity across 195 countries via direct connections to over 1600 local carrier networks.
The advanced chat and audio features of this software will enable organizations and developers to build communication apps using SIP SDKs and APIs.
Bottom Line
Get your company ready for SIP and VoIP calls! As SIP calling reduces 70% of communication costs compared to traditional phone systems, now it’s your time.
If you use PBX connections, you can transform your whole phone call experience using SIP trunking. With minimal effort, you can implement a session initiation protocol with multiple features.
Moreover, if you want to establish SIP in a matter of hours, consider self-hosted SIP/VoIP API as the best choice. With MirrorFly, you can customize features and even change the logo, font color and customization font as you want.
Contact MirrorFly for more information and pricing. Good luck on your SIP connections!
Further Articles
- What is VoIP Phone? – A Complete Guide in 2025 for Beginners
- How Does VoIP Work? Overview To VoIP Phone Systems
- What is SIP Calling & How Does It Work?
