List of the Top 25 On-Prem Telephony Software in 2025

A dynamic platform and specialized applications designed specifically for MSPs and UCaaS Providers. Transform your business with modern communication and telephony systems that improve customer interactions while minimizing upfront investments. Widely adopted by numerous international clients, UCaaS providers, and resellers, Thirdlane stands out as the go-to solution for those aiming to gain a competitive edge. Whether serving enterprises of various sizes, governmental organizations, or call centers, Thirdlane's dependable and intuitive multichannel communication solutions enhance productivity, foster customer engagement, drive sales, and improve cost-effectiveness. Explore how Thirdlane can strengthen your organization by requesting a quote today. Additionally, alongside the telephony features offered by the Thirdlane Multi Tenant PBX or Thirdlane Business Phone System, customers also enjoy access to the Thirdlane Connect application (available on both desktop and mobile), which encompasses chat, voice and video calls, conferencing, screen sharing, and seamless integration with CRM systems and various applications, providing a comprehensive communication experience. This robust array of features is designed to meet the evolving needs of today's businesses.

PBXware stands out as the original and most prominent IP PBX Professional Open Standards Turnkey Telephony Platform available today. Since its inception in 2004, PBXware has been delivering adaptable, dependable, and scalable Next Generation Communication Systems (NGCS) alongside VoIP solutions tailored for small and medium-sized businesses (SMBs), large enterprises, Internet Telephony Service Providers (ITSPs), call centers, and various governmental agencies across the globe. This achievement is realized by integrating the finest elements of cutting-edge technologies. The Bicom Systems softswitch is offered in several editions, including Business, Call Center, and Multi-Tenant, with each edition designed to support specific features that enhance performance, reliability, and expandability, ensuring users get the most out of their systems. This versatility makes PBXware a preferred choice for organizations seeking robust telephony solutions.

VitalPBX is a comprehensive PBX platform built on Asterisk and designed to operate on Centos 7. This powerful and adaptable platform enables users to effortlessly manage their PBX systems with ease. With an intuitive user interface complemented by helpful tooltips, navigating through the system is straightforward. It is essential for telephony systems to remain vigilant about potential security vulnerabilities and implement measures to mitigate these risks. VitalPBX provides multiple layers of defense to safeguard against cyber threats in the realm of VoIP communications. Moreover, its security features ensure that users can maintain a reliable and secure communication environment.

The *astTECS IPPBX system serves as the perfect solution for businesses of all sizes, ensuring a comprehensive set of high-end features at a reasonable cost while holding TEC certification from the Government of India. This innovative PBX solution empowers organizations to be adaptable, forward-thinking, and competitive, all while streamlining telecom costs. Additionally, the *astTECS Call Center Dialer stands out as an omnichannel contact center solution, featuring a sophisticated real-time dashboard to monitor agents effectively. With the incorporation of advanced analytics and AI-driven capabilities, this dialer significantly enhances both agent productivity and customer interactions. Furthermore, *astTECS offers a robust call recording solution tailored for your business needs, with an intuitive voice recorder that boasts a range of advanced functionalities. Seamless integration with various PBX systems is a key benefit, as it supports ISDN/PRI, IP, analog lines, and mobile networks, ensuring comprehensive recording of all incoming and outgoing calls. This all-in-one solution not only optimizes communication but also facilitates better decision-making through detailed call insights.

Toll-free and local numbers are offered in over 160 nations, allowing you to forward incoming calls from any phone, PBX, or SIP system. Our extensive global network is designed with multiple layers of redundancy to ensure reliability. You can utilize any of your business numbers as Caller ID for international outbound calls, and displaying a local caller ID can significantly enhance your success rates. To facilitate outbound calling, simply connect our SIP trunks to your existing phone system. Implementing smart calling routing features like auto-attendant/IVR, time-based routing, and simultaneous ringback tones is straightforward. You also have the flexibility to customize greetings, record calls, manage voicemail, and access call recording functionalities. Adjustments to virtual numbers, calling plans, and advanced features can be done effortlessly, while you can also download call detail records and invoices. Technical support is available around the clock, ensuring assistance whenever you need it. For personalized help, reach out to your dedicated account manager. Additionally, our user-friendly interface allows you to manage all aspects of your communication seamlessly, enhancing your overall experience.

Smartz Solutions is revolutionizing the contact center industry by challenging outdated systems that have long kept businesses trapped with their complicated setups and exorbitant costs. Many contact centers are fatigued from managing fragmented and pricey systems, which adversely affect both customer satisfaction and employee morale. Our AI-driven 360° experience platform is transforming the way contact centers operate. Having experienced these challenges firsthand, we understand the pain of investing in legacy systems. At one point, we operated 15 different systems, all sluggish and ineffective, just to keep our call center running. We empathize with the struggle of trying to locate essential customer data and the frustration that arises when employee information is scattered across various platforms, obscuring the overall business picture. There's no need for you to operate your call center at the expense of lost revenue, missed opportunities, and dwindling patience. By utilizing a holistic technological framework, you can finally gain a comprehensive view of your entire customer base, enhancing both service delivery and operational efficiency. This shift not only streamlines processes but also empowers teams to deliver exceptional experiences.

We drive human progress through teamwork, connectivity, and advanced communication technologies. Every aspect of business revolves around people, and when tailored technology enhances human creativity, both individuals and organizations flourish. Teams that excel accomplish greater feats, reach higher goals, and experience increased success. Organizations become more agile, efficient, and adaptable to change. Our team is dedicated to simplifying technology and keeping it affordable. Our passion for our work is evident in how we collaborate with you, starting from our initial discussion and continuing with ongoing support after installation. Serving over 30,000 customer locations across more than 65 countries, we provide clear, secure, and scalable global managed services along with sophisticated collaboration and communication solutions. Let's work together to enhance your human potential and foster innovation. By combining our expertise with your vision, we can create remarkable outcomes.

Intrado offers a comprehensive cloud-based calling solution designed for enterprises that is entirely managed and hosted. This service encompasses team collaboration features such as messaging, meetings, and mobility options, along with the advantages of Cisco Webex devices. Additionally, VoiceMaxx CE integrates the Cisco Hosted Collaboration Solution (HCS), a cloud service that builds upon the established on-premises Call Manager system provided by Cisco. This makes it an excellent option for medium to large businesses transitioning from traditional on-premise services. The solution is backed by Intrado's geo-redundant Data Centers, ensuring superior business continuity and disaster recovery capabilities. Furthermore, Intrado’s engineering team is on hand around the clock to provide support and assistance whenever needed. This level of support is crucial for maintaining seamless operations in a dynamic business environment.

The word "Free" in FreePBX embodies the concept of Freedom, underscoring that FreePBX is the foremost open-source IP PBX solution worldwide, which enables users to design a tailored phone system that aligns with their unique needs. Delve into the possibilities of open-source communication and investigate the wide array of features offered by FreePBX that assist in building your perfect phone system. By incorporating commercial modules from Sangoma and a variety of other enhancements, you can transform your FreePBX setup into a robust Unified Communications platform. Remember to consult the Knowledge Base on the FreePBX Wiki for further information! Alternatively, seeking support from FreePBX experts can aid you with installation, updates, troubleshooting, and additional services. FreePBX is accessible for free download and usage, and its strength is bolstered by a global community of developers committed to ensuring its high compatibility and flexibility, which guarantees it encompasses all necessary functionalities required to establish a scalable business phone system for any budget. This community-driven approach not only promotes innovation but also ensures ongoing advancements, solidifying FreePBX as a dependable option for diverse communication requirements. With its extensive resources and community support, users can continually enhance their experience and capabilities.

TekSIP for Windows functions both as a SIP Registrar and a SIP Proxy, accommodating various transport protocols including UDP and TCP for both IPv4 and IPv6, as well as TLS and WebSocket, with only the commercial versions offering support for Secure WebSocket and TLS. It has been verified to operate on Microsoft Windows Vista, 7, 8, 10, and 11 servers, serving as a signaling service for SIP-based phones utilizing WebRTC technology. In addition, TekSIP adheres to several RFC standards, including RFC 3261, RFC 3263, RFC 3581, RFC 3891, RFC 3311, and RFC 3481, enabling NAT traversal and ENUM functionality. Users are able to select the listening IP address and alternative SIP endpoints for outgoing calls, while session details can be logged for review alongside real-time monitoring of registrations and active sessions. The Windows Performance Monitor (Perfmon.exe) facilitates tracking of active sessions and registrations, enhancing oversight. Furthermore, in cases where the intended endpoint is unavailable—whether due to being offline or busy—TekSIP redirects calls to an alternate endpoint, ensuring seamless communication. Additionally, the graphical user interface (GUI) provides users the capability to terminate any active SIP session easily.

OfficeConnect™ offers a comprehensive solution that integrates voice, conferencing, messaging, and fax services. Our VoIP phones present a more adaptable and cost-effective alternative to traditional on-premises systems. With our advanced audio and video conferencing capabilities, you can ensure that your projects stay on track while keeping your teams in sync effortlessly. UniVoIP takes security seriously by encrypting all voice communications, whether from remote locations or on-site telephones. It employs SRTP with 128-bit AES encryption, meeting the stringent requirements of federal standards, including FIPS 140-2 Certified encryption and the Department of Defense's PKI Digital Certificate, thereby providing an additional layer of trust in your communications. This commitment to security and functionality makes OfficeConnect™ a reliable choice for modern businesses.

Asterisk is a dynamic open-source framework that facilitates the development of a variety of communication applications. It enables a standard computer to function as a powerful communications server. Asterisk is integral to IP PBX systems, VoIP gateways, conference servers, and many other customized solutions. Its user base includes small businesses, large corporations, call centers, telecom operators, and government entities around the world. Provided free of charge, Asterisk is backed by Sangoma's support. Currently, there are over a million Asterisk-powered communication systems in operation across more than 170 countries. Notably, virtually all companies within the Fortune 1000 list leverage Asterisk in some form. Frequently adopted by system integrators and developers, Asterisk can serve as the basis for a complete business phone system or be used to enhance an existing setup or link various systems. Whether you aim to design a bespoke system using Asterisk or are interested in acquiring an effective and affordable turnkey solution, there are numerous options to explore that can help you find the perfect match for your requirements. As it adapts to technological advancements and user needs, Asterisk remains a key player in the evolving landscape of modern communication solutions. Its ongoing development ensures users continue to benefit from innovative features and improved performance.

HoduPBX stands out as an exceptional choice for enhancing business communication. Its distinctive user interface, combined with an optimal user experience, ensures that businesses can interact efficiently with their clients and stakeholders. This software excels in providing seamless connectivity, whether in a traditional office setting or remote locations, thereby facilitating smooth communication. Additionally, HoduPBX enhances agents' productivity through its multitasking features and streamlined operations. As a robust IP PBX solution, it can handle over 1000 concurrent calls and accommodates up to 10,000 extensions, making it an ideal option for diverse business needs. The HoduPBX IP PBX Software is equipped with a range of advanced functionalities, including Add-on Modules, a Reseller Module, SIP Trunking, Queue Pro, Voice Transcription, and Webphone capabilities. Moreover, it supports white label options across various platforms such as iOS, Android, Chrome Extension, Windows, Mac, Linux, and the ZohoPhonebridge Plugin, ensuring versatility and adaptability for all types of users. This comprehensive feature set positions HoduPBX as a leading solution in the realm of business communication technologies.

For more than twenty years, Diabolocom has been revolutionizing the way businesses engage with their customers through its innovative cloud-native Contact Center as a Service (CCaaS) platform. Utilizing exclusive generative AI technology, Diabolocom offers sophisticated automation, enhanced accessibility, and insightful analytics designed to meet the evolving requirements of customer service and sales. The AI Assistant provided by Diabolocom enriches each customer interaction by delivering real-time transcription, evaluating satisfaction levels, and offering guidance on the most effective next steps to take. What sets Diabolocom apart is the seamless integration of native AI focused on customer experience alongside comprehensive telecom capabilities, resulting in a highly personalized telephony service. By streamlining repetitive tasks, organizations can shift their attention towards fostering customer loyalty and enhancing revenue generation. Our solution can be integrated either natively or through APIs with popular CRM platforms such as Salesforce, Oracle, and Microsoft Dynamics, guaranteeing thorough visibility across all customer interactions. Esteemed brands like Mitsubishi Electric, Nikon, and Brinks trust Diabolocom to provide unique, AI-enhanced customer experiences. With a remarkable 97% reduction in post-call handling times and a 12% decrease in customer churn, our platform not only boosts operational efficiency but also empowers teams to remain adaptable in a fast-changing market landscape. This commitment to innovation is why Diabolocom continues to lead the industry in customer engagement solutions.

CompletePBX, Xorcom's core telephone system solution, serves as a Virtual IP PBX (Private Branch Exchange) or Phone System Appliance, integrating Asterisk and Linux to ensure robust stability and high operational performance. Developed with user-friendliness, advanced functionalities, and comprehensive security in mind, CompletePBX is designed to meet the diverse needs of modern communication. You can access a fully functional evaluation of the CompletePBX 5 virtual machine at no cost! Additionally, free online certification training for CompletePBX is offered, providing a foundational understanding of the system that can significantly streamline your learning process. With our assistance, you can expedite your journey to mastering this powerful phone system.

FusionPBX acts as a multifaceted solution suitable for both single and multi-tenant PBX configurations, functioning effectively as a carrier-grade switch, call center system, fax server, VoIP server, voicemail server, conference server, and voice application server, among various other functions. In contrast, FreeSWITCH™ is recognized for its flexibility and scalability, operating seamlessly across multiple threads and platforms. It offers a rich set of features, such as unlimited extensions, voicemail-to-email, music on hold, call parking, call center functions, call queues, and phone provisioning, making it ideal for businesses of varying sizes. By providing enterprise-grade phone system capabilities, it effectively addresses the diverse requirements of small, medium, and large organizations alike. Considerable resources have been dedicated to bolstering security, addressing technical issues, and enhancing the codebase. In addition, there are continuous improvements underway in anticipation of a forthcoming release, with the master branch exhibiting advancements that surpass the current version in multiple areas. As the team diligently finalizes critical updates, excitement builds regarding the forthcoming enhancements, which promise to elevate user experience. This dedication to ongoing enhancement is a testament to the platform's commitment to staying competitive and relevant amid the fast-paced changes in the telecommunication industry, ensuring it meets the ever-evolving demands of its users.

Vodia is a PBX solution that operates on both Windows and Linux platforms, delivering a comprehensive suite of advanced functionalities typically associated with robust PBX systems, such as call queues, auto attendants, and call forwarding capabilities. Additionally, Vodia stands out as a leader in Multi-Tenancy, allowing users to deploy it on a dedicated virtual machine in the cloud or on-site while managing numerous fully qualified domain names for different clients. You can experience Vodia by signing up for a free demo license, valid for 60 days, to explore its features firsthand. This trial is an excellent opportunity to see how Vodia can cater to your specific telecommunication needs.

The on-premises business phone system that offers all the vital tools needed for your organization to improve customer engagement. Central to Mitel's top-tier on-site communication solutions is MiVoice Business, which encompasses MiCollab, MiTeam Meetings, and MiContact Center Business, enabling staff to enjoy the advantages of integrated, scalable, and mobile communications effortlessly. This system provides your organization with everything required to raise communication standards through efficient mobility, collaborative teamwork, video conferencing, and exceptional customer experience management. MiVoice Business is designed to serve businesses of varying sizes, from 5 to 130,000 users, whether they operate from a single venue or multiple locations across the globe. Additionally, the software deployed on Mitel Collaboration Service Appliances can function on standard x-86 servers within a virtual environment, simplifying processes by minimizing the need for numerous devices—this is particularly beneficial for clients choosing a centralized unified communications approach. With MiVoice Business, companies can guarantee that their communication framework is both adaptable and strong, promoting continuous growth and innovation. Ultimately, this comprehensive solution empowers organizations to meet the ever-evolving demands of modern communication.

Achieve a rapid return on investment through improved cost savings, streamlined operations, and superior customer service. Our Call Management System (CMS4) provides organizations with the necessary tools to effectively oversee their telephony costs, complete with comprehensive performance analytics. Whether managing a small setup or an expansive, international network, CMS4 delivers critical insights in your desired format. The system can be implemented as an On-Premises solution, a Cloud-based option, or as a fully managed hosted service. CMS4 allows users to scrutinize traffic at every gateway or trunk group, producing grade of service reports that indicate whether capacity meets current demand. By utilizing this information, organizations can ensure their systems run efficiently to meet existing requirements while also preparing for future growth. This flexibility not only maximizes resource utilization but also equips businesses to thrive in an evolving market landscape. As a result, adopting CMS4 can significantly enhance an organization's strategic positioning for long-term success.

The Taridium IPBX represents a cutting-edge VoIP PBX solution that replaces traditional hardware systems with a software-based alternative. It functions effortlessly on standard server setups or through cloud services while avoiding the burden of additional licensing fees. An End User Panel is available, allowing users to manage their extensions effectively, including actions like handling calls through an operator console, checking voicemail, configuring call forwarding, and setting up spontaneous phone conferences, among other functionalities. Users can tailor their extension settings to forward calls during specified times by linking their iCalendar feed or by selecting preferred caller IDs from a provided list. Additionally, each user receives a meet-me style conference room, which helps in eliminating scheduling issues and allows for real-time management of conference calls, with handy options to mute or remove participants as necessary. Inviting additional participants is made easy; one simple click prompts the system to dial them directly, sidestepping the complexities of tedious login steps. This innovative system transforms the user experience by providing intuitive controls and unmatched flexibility, ultimately boosting communication efficiency and collaboration. Moreover, its ability to integrate with existing tools and workflows further enhances its appeal to businesses looking for seamless connectivity.

Softdial Contact Center™ represents Sytel’s premier collection of comprehensive contact center software and services. It effectively supports over 50,000 customers across more than 50 nations. The platform’s powerful APIs are designed for customization, adaptation, and white-labeling to align with diverse business requirements. SCC efficiently oversees all communication mediums, such as voice calls, chats, emails, and messaging, seamlessly integrating and managing interactions among agents, queues, and campaigns through its Automatic Session Distributor. This versatility ensures that businesses can maintain optimal communication flow and enhance customer engagement across various platforms.

All the necessary resources for interacting with the FreeSWITCH platform are available right here. FreeSWITCH acts as a Software Defined Telecom Stack, enabling a transition from conventional telecom switches to a versatile software-based solution that can run on any standard hardware, from a Raspberry PI to a robust multi-core server, thus amplifying the telecommunications functionalities of various devices. When integrated with our cloud platform, SignalWire, FreeSWITCH can effortlessly connect to external networks and scale operations as needed. To ease your onboarding process, a pre-configured virtual machine is offered, equipped with extensive written and video tutorials, so you can quickly get started with just a VirtualBox installation. For those who are more technically inclined, comprehensive instructions are provided for compiling FreeSWITCH from source or exploring alternative manual installation techniques. Furthermore, if you have access to a Debian instance, you will find detailed guidance on installing our packages from the provided link, allowing for a flexible approach to implementing FreeSWITCH. This platform truly empowers both novices and experienced developers, making telecommunications more approachable than ever while fostering innovation and creativity in the field. Whether you’re looking to build a simple communication tool or a complex telecom solution, FreeSWITCH has the capabilities to meet your needs.

Established in January 2015, sipXcom was created as a result of a split from the sipXecs project, driven by the eZuce, Inc. development team. The challenges faced by the sipXecs and SIPfoundry communities in broadening their developer pool due to restrictive contributor agreements led to the inception of sipXcom, which embraces an open contribution model. The sipXcom source code is distributed under the copyleft-friendly AGLP v3 (Affero General Public License), which offers developers increased flexibility. Currently, SWARM is the project name for the next version of sipXcom and sipXecs, with a production release anticipated in early 2017. This forthcoming platform will be built on a microservices architecture, aimed at improving scalability, reliability, and configurability compared to the existing sipX offerings. SWARM is designed to function seamlessly across various computing environments, such as dedicated, virtual, or cloud servers, while also supporting hybrid configurations that integrate on-premise and cloud solutions. With these innovative features, sipXcom aspires to enhance user experience and operational capabilities in the dynamic realm of communication technology. As the development progresses, the team is committed to addressing the evolving needs of users in this space.

A cloud contact center solution driven by AI, this platform enhances communication through innovative, personality-based routing. It efficiently consolidates multichannel customer interactions into a single conversation thread. Vocalcom represents the intersection of digital engagement and artificial intelligence, allowing for a seamless integration of live agents within the customer interaction process. With the ability to manage all customer interactions collectively, this next-generation cloud contact center platform is designed to integrate smoothly with existing systems while supporting every communication channel available. By offering an intuitive user interface, Vocalcom boosts productivity and empowers businesses to unify their customer interactions across various platforms into continuous conversational threads. This approach not only minimizes customer effort but also fortifies relationships with each touchpoint. Remarkably user-friendly, flexible, and fueled by AI, it ensures that conversations remain active and accessible. Every type of customer interaction, such as chat, email, text, phone, and social media, is conveniently centralized, making it easier for businesses to engage with their clients effectively.

The Blueface VoIP phone system guarantees that your business is equipped for any circumstance by enabling you to take calls on any device, regardless of your work setup—whether it’s remote, in an office, or a hybrid arrangement. This flexible cloud-based phone solution is tailored to accommodate businesses of all sizes and can be effortlessly adjusted to meet evolving demands. Start your path with Blueface today and discover a powerful IP business phone solution that supports your organization's growth. You can cut costs by minimizing line rental fees and potentially reducing your phone bills by as much as 40%. With over 60 features at your disposal, including IVR, Softphone capabilities for mobile and desktop, call recording, and more, our system offers extensive communication solutions. The self-service web portal empowers you with total control over your communication settings, while our diverse range of desk and DECT hardware options serves every level of your organization. Experience unlimited, high-quality audio conferencing through Blueface Unified Communications and Poly, and take your landline with you via the Blueface Softphone App, which also features recording options. Moreover, Blueface provides a comprehensive suite of continuity services to ensure that you stay connected at all times, enabling your business to function smoothly even during unexpected challenges. With such an extensive array of features and services, Blueface is dedicated to enriching your business communication journey, ensuring that you can adapt to the ever-changing landscape of modern work. This commitment to flexibility and scalability makes Blueface an invaluable partner for any organization aiming to thrive.