Best On-Premises Telephony Software of 2025

Thirdlane is built for service providers and MSPs who need a multi-tenant, white-label UCaaS platform with deep API control. It delivers voice, video, chat, and contact center features while giving providers the ability to integrate billing, CRM, and IT workflows with ease. Why providers choose Thirdlane: - True multi-tenant PBX architecture built for scaling to thousands of tenants. - White-label flexibility - deliver a branded experience to your customers. - Thirdlane Connect apps unify messaging, calling, and meetings across all devices. - Built-in Contact Center for sales and support teams. - CRM screen pops and Click-to-Call to boost productivity. - Extensive APIs for automation and third-party integrations. Business outcomes: - Launch branded UCaaS without the heavy R&D cost. - Increase recurring revenue with scalable multi-tenant architecture. - Offer enterprise-grade features at a competitive price point. Thirdlane empowers providers to own their UCaaS offerings end-to-end, increasing margins and ensuring long-term customer loyalty.

PBXware is the first and most established IP PBX Professional Open Standards Turnkey Telephony Platform. PBXware has been providing flexible, reliable and scalable Next Generation Communication Systems (NGCS) and VoIP solutions to small and medium-sized businesses (SMBs), enterprises and Internet Telephony Service Providers, (ITSPs), call centers and governments around the world since 2004. This is done by combining the best of the latest technologies. Bicom Systems softswitch is available in the Business, Call Center, and Multi-Tenant Editions. Each edition supports specific features that maximize performance, reliability, expandability, and expandability.

VitalPBX is a unified communications PBX platform based on Asterisk (Centos 7). VitalPBX is a robust, scalable platform that will allow you to manage your PBX in a simple and intuitive manner. VitalPBX has a simple user interface and tooltips throughout the system. Telephony systems should be aware of security risks and take steps to avoid them. VitalPBX offers a variety of levels of protection against cyber threats in VoIP.

*astTECS IPPBX system is the ideal solution for any business, large or small. *astTECS PBX has all the top-end features at an affordable price and is TEC certified by DoT (Govt of India). *astTECS IPPBX solution allows your business to be flexible, innovative, competitive, and future-ready while reducing telecom expenses. *astTECS Call Center Dialer is an omnichannel contact centre solution that offers advanced features and a real-time dashboard for agent monitoring. Advanced analytics and AI-based call center dialer will improve agent productivity and customer engagement. *astTECS provides a complete call recording solution for your company. *astTECS voice recorder is easy to use and offers advanced features. Integration with any PBX is seamless. Supports ISDN/PRI, IP, analog lines and mobile to record all incoming and outgoing calls.

Toll-free and local numbers are available from more than 160 countries. Forward incoming calls from any phone, PBX, or SIP. Our global network offers multiple layers of redundancy. You can make international outbound calls by using any of your business numbers as a Caller ID. Showing a local caller ID will increase your success rate. To make outbound calls, connect our SIP trunks with your phone system. You can easily set up and modify smart calling routing features such as auto-attendant /IVR, location and time-based routing, and simultaneous ringback tones. Custom greetings, call recording, voicemail, and call recording are all possible. You can easily add or remove virtual numbers, modify calling plans, download call detail records and invoices, modify advanced features, and reach technical support 24/7. Contact your account manager.

Smartz Solutions is a disruptor that is reshaping contact center landscape. The traditional legacy systems have been holding businesses hostage too long with their complex infrastructures and high fees. Contact centers are tired from being burdened with disjointed, expensive systems that have a negative impact on customer and employee experience. Our AI-powered 360° experience platform is redefining contact centre experiences. We've been there. We paid for legacy systems. We had 15 systems running simultaneously (at snail's speed) to be able run our call center. We understand the frustration of not being able (sometimes even) to find data to help customers. We know how frustrating it is to have employee data scattered across multiple systems, never allowing a clear picture of the business. You don't have run your call center by losing money, opportunities, and patience. With a comprehensive tech stack you can finally have your entire customer base.

We unleash human momentum with collaboration, connectivity, and communications technology. All business is human—and when custom technology empowers human ingenuity, people and companies thrive. High performing teams do more, achieve more, and win more. Companies become agile, efficient, and resilient. Our team takes pride in making technology easy and cost effective. We love what we do—and it shows in the way we partner with you, from our first conversation to ongoing post-install support. Working with over 30,000 customer locations in 65+ countries, we deliver straightforward, secure, and scalable global managed services and advanced collaboration and communications solutions. Together let’s build your human momentum.

Intrado provides a cloud-based enterprise-grade calling solution that is fully hosted and managed. This includes team collaboration which includes messaging, meeting and mobility solutions as well as the benefits and features of Cisco Webex devices. VoiceMaxx CE also includes Cisco Hosted Collaboration Solution, (HCS), which is a cloud service that builds on Cisco's tried-and-true on-premises Call Manager offering. This makes it an ideal service choice for medium to large companies switching from a premise-based service. Intrado fully supports this solution with geo-redundant Data Centers, which provide enhanced business continuity and disaster recovery. Intrado engineers are available 24/7 to support you.

The term "Free" in FreePBX signifies Freedom, highlighting that FreePBX, the leading open-source IP PBX solution globally, empowers users to create a customized phone system that meets their specific requirements. Explore the potential of open-source communication and examine the extensive range of features that FreePBX provides to help you construct your ideal phone system. By integrating commercial modules from Sangoma and various other add-ons, you can elevate your FreePBX installation into a powerful Unified Communications platform. Don't forget to check the Knowledge Base on the FreePBX Wiki for additional resources! Alternatively, you can reach out to FreePBX professionals for assistance with installation, updates, troubleshooting, and more. Available for free download and use, FreePBX's strength is supported by a worldwide community of developers dedicated to maintaining its high compatibility and customizable nature, ensuring it delivers all the essential functions needed to create a scalable business phone system that accommodates any budget. This collaborative effort fosters innovation and continuous improvement, making FreePBX a reliable choice for communication needs.

TekSIP for Windows is a SIP Registrar as well as a SIP Proxy. TekSIP supports UDP (IPv4 & IPv6), TCP (IPv4 & IPv6), TLS, and WebSocket transports. Only commercial editions support Secure WebSocket and TLS. TekSIP has been tested on Microsoft Windows Vista and Windows 7/8/10/11 servers. TekSIP is a signaling service for WebRTC based SIP-based phones. TekSIP is compliant with RFC 3261 and RFC 3263. It also complies to RFC 3581, RFC 3891, RFC 3311 and RFC 3481. It supports NAT traversal, ENUM. Please refer to Readme for technical details on NAT traversal. You can choose the IP address that will be listened to and alternative SIP endpoints when making outgoing calls. You can also log the session details in a log and monitor registrations and active sessions in real-time. Windows Performance Monitor (Perfmon.exe) allows you to monitor the number of active sessions and registrations. TekSIP redirects calls to an alternate endpoint if the called endpoint is not available (Offline, busy ...). GUI can be used to terminate an active SIP session.

Issabel stands out as an open-source unified communications platform that merges various IP communication services into one cohesive system, effectively overcoming the limitations of traditional PBX systems by offering features like call center functionalities, email integration, management reporting, fax capabilities, video conferencing, audio recording, and CRM integrations. Its call center module is not only robust and flexible but also user-friendly, enabling efficient automation and management of contact centers while adeptly handling both inbound and outbound call campaigns through a straightforward agent interface and call management tools. Additionally, Issabel simplifies the administration of PBX solutions for service providers, allowing them to manage multiple clients from a single instance, thus alleviating the need for individual servers for each client. To further expand its capabilities, Issabel accommodates various add-ons that are designed to integrate seamlessly with the platform, enhancing features that interact with telephony and improve customer service while automating support-related actions. This adaptability makes Issabel a highly effective choice for organizations looking to streamline their communication processes.

OfficeConnect™, provides unified voice, conferencing and messaging as well as faxing. Our VoIP phones are more flexible and cheaper than legacy on-premises systems. You can keep your projects moving and synchronize teams with best-in class audio and video conference made easy. UniVoIP encrypts all voice traffic, both from remote and on-site telephones. It uses SRTP with 128 bit AES encryption. SRTP conforms to both the federal standards FIPS 140-2 Certified encryption and the Department of Defense's PKI Digital Certificate.

Asterisk is a versatile open-source framework designed for creating various communication applications. It transforms a standard computer into a robust communications server. Asterisk serves as the backbone for IP PBX systems, VoIP gateways, conference servers, and numerous other tailored solutions. Its users range from small enterprises to large corporations, call centers, telecom carriers, and government bodies across the globe. Available at no cost, Asterisk thrives under the sponsorship of Sangoma. Currently, over a million Asterisk-based communication systems operate in more than 170 nations. Remarkably, nearly all companies listed in the Fortune 1000 utilize Asterisk in some capacity. Most frequently implemented by system integrators and developers, Asterisk can serve as the foundation for a comprehensive business phone system or can be employed to augment an existing setup or connect disparate systems. Whether you're interested in crafting a personalized system with Asterisk or purchasing an efficient, affordable turnkey solution, explore the options available to determine the best fit for your needs. With its flexibility and wide-ranging applications, Asterisk continues to evolve, ensuring it meets the demands of modern communication.

HoduPBX is the best solution for business communication. HoduPBX's unique user interface and optimal user experience allow businesses to communicate efficiently with their end users. This software provides unparalleled connectivity in an office environment and remote locations, making communication seamless. HoduPBX empowers agents' work management with multitasking capabilities and efficiency. Our IP PBX software is a great choice for business communications. It supports 1000+ concurrent calls and has 10,000 extensions. HoduPBX IP PBX Software offers various sophisticated features such as Add-on Modules, Reseller Module, SIP Trunking, Queue Pro, Voice Transcription, and Webphone. It also offers white label features across IOS, Android, Chrome Extension, Windows, Mac, Linux, and ZohoPhonebridge Plugin.

For over two decades, Diabolocom has been transforming customer engagement with our cloud-native Contact Center as a Service (CCaaS) solution. Powered by proprietary generative AI, Diabolocom delivers advanced automation, improved reachability, and actionable insights tailored to today’s customer service and sales demands. Our AI Assistant enhances each interaction through real-time transcription, satisfaction analysis, and predictive next-best-action guidance. What makes Diabolocom unique is our combination of native AI for CX and full telecom functionality, creating a hyper-customized telephony experience. By automating repetitive processes, teams can redirect their focus to driving customer loyalty and revenue growth. Our solution integrates natively or via API with CRMs such as Salesforce, Oracle, and Microsoft Dynamics, ensuring complete visibility across every touchpoint. Leading brands like Mitsubishi Electric, Nikon, and Brinks rely on Diabolocom to deliver differentiated, AI-optimized customer experiences. With 97% faster post-call handling and a 12% reduction in churn, our platform drives efficiency and keeps teams agile.

Virtual IP PBX (Private Branch Exchange), or Phone System Appliance – CompletePBX is the heart and soul of Xorcom's hardware and software telephone systems. It's built on top of Asterisk and Linux platforms and is designed for stability and high performance. CompletePBX was built from the ground up to offer ease-of-use, advanced features, and security at all levels. Get a fully functional, free CompletePBX 5 virtual machine evaluation now! CompletePBX certification training is available online for free. It will guide you through the basics of the system. You can save a lot of time and effort if you do it yourself. We can help you get there quicker.

FusionPBX serves as a versatile solution for both single and domain-based multi-tenant PBX setups, functioning as a carrier-grade switch, call center system, fax server, VoIP server, voicemail server, conference server, and voice application server, among other roles. Meanwhile, FreeSWITCH™ stands out as a highly adaptable and scalable communication platform that operates across multiple threads and platforms. It boasts an impressive array of features, including unlimited extensions, voicemail-to-email, music on hold, call parking, call center capabilities, call queues, and phone provisioning, catering to businesses of all sizes. By delivering corporate-level phone system functionalities, it meets the diverse needs of small, medium, and large enterprises alike. Significant efforts have been invested in enhancing security, resolving issues, and refining the codebase. Furthermore, ongoing advancements are being made in preparation for an upcoming release, with notable progress achieved; the master branch has outpaced the current version in several respects. As the team works meticulously to finalize the essential updates, anticipation builds for the enhancements that will accompany this release. The commitment to continuous improvement ensures that the platform will remain competitive and relevant in the rapidly evolving telecommunication landscape.

Vodia is a software-based PBX that runs on Windows and Linux. It offers all the advanced features you would expect from a full-featured PBX, including call queues, auto attendants and call forwarding. Vodia is also the pioneer in Multi-Tenancy. You can host Vodia on a dedicated VM( Virtual Machine) in the cloud, premises, and maintain multiple FQDNs for each customer. Sign up for a hosted demo license code for 60 days.

The Blueface VoIP phone system ensures your business is equipped to handle any situation. You can take calls from any device, regardless of whether you're working remotely, in an office, or using a hybrid approach. This versatile and scalable cloud-based phone solution is suitable for businesses of all sizes. Start your journey with Blueface today to experience a business phone system that fosters growth. By switching to this IP phone system, you can reduce line rental costs and save as much as 40% on your phone expenses. With over 60 features—including IVR, Softphone (for both mobile and desktop), call recording, and more—this system enhances your communication capabilities. The intuitive self-service web portal empowers you to manage your communications effectively. Choose from a diverse selection of desk and DECT hardware, catering to all levels from entry-level to executive. Additionally, enjoy unlimited, high-quality audio conferences powered by Blueface Unified Communications and Poly. The Blueface Softphone App allows you to carry your landline with you on your mobile device while also providing recording features. Furthermore, Blueface offers various continuity services to ensure you remain connected at all times, no matter where you are. This comprehensive approach to communication sets Blueface apart as a leader in the VoIP industry.

The on-premises business phone solution that provides all the essential tools for your organization to enhance customer interactions. At the core of Mitel's premier on-site communication offerings lies MiVoice Business, which includes MiCollab, MiTeam Meetings, and MiContact Center Business, allowing employees to reap the benefits of unified, scalable, and mobile communication seamlessly. This solution equips your business with everything necessary to elevate communication standards through effective mobility, team collaboration, video conferencing, and outstanding customer experience management. MiVoice Business is tailored to accommodate businesses ranging from 5 to 130,000 users, whether operating from a single location or across multiple sites worldwide. Furthermore, the software installed on Mitel Collaboration Service Appliances can run on standard x-86 servers within a virtualized setup, streamlining operations by reducing the need for multiple appliances—an especially valuable feature for clients opting for a centralized unified communications deployment. With MiVoice Business, organizations can ensure that their communication infrastructure is both flexible and robust, fostering growth and innovation.

Experience a swift return on investment through enhanced cost savings, operational efficiencies, and elevated customer service. Our Call Management System (CMS4) equips organizations with the tools to manage their telephony expenses effectively, offering in-depth performance analytics. Regardless of whether you operate a small system or a vast, globally clustered network, CMS4 supplies the essential information you need in your preferred format. The system can be deployed as an On-Premises, Cloud, or fully managed hosted service solution. CMS4 enables you to analyze traffic at each gateway or trunk group, generating grade of service reports that reveal whether your capacity aligns with demand. By leveraging this data, organizations can ensure their systems operate efficiently to accommodate present needs while also anticipating future demands. This adaptability not only optimizes resources but also positions businesses for sustained growth.

The Taridium IPBX is an advanced software-based VoIP PBX solution that effectively takes the place of conventional hardware PBX systems. It operates seamlessly on standard server infrastructure or via cloud services without necessitating additional licensing costs. Users benefit from an End User Panel that empowers them to manage various aspects of their extensions, including call operations through an operator console, accessing voicemail, setting up call forwarding, and initiating impromptu telephone conferences among other features. You can customize your extension to forward calls only during specific hours by integrating your iCalendar feed or by selecting from a list of preferred caller IDs. Each user is provided with a meet-me style conference room, eliminating scheduling conflicts and enabling live management of conference calls, including options to mute or remove participants as needed. Inviting users is straightforward, requiring just a click to have the system initiate a call to them, thus avoiding the hassle of complicated login procedures. This system redefines user experience by offering intuitive controls and flexibility that enhance communication efficiency.

Softdial Contact Center™ is Sytel’s flagship suite of feature rich contact center applications and service. It is currently driving 50,000+ customers in 50+ countries. SCC's robust APIs can be customized, adapted, and white-labeled in order to meet any business needs. SCC manages all communication channels, including voice, chat, emails, and messaging, automatically blending and balancing contact between all agents, queues, and campaigns using its Automatic Session Distributor.

Everything essential for engaging with the FreeSWITCH platform is provided here. FreeSWITCH serves as a Software Defined Telecom Stack, facilitating the shift from traditional telecom switches to a flexible software solution that can operate on any standard hardware, whether it’s a Raspberry PI or a powerful multi-core server, thus unleashing the telecommunications capabilities of various devices. When paired with our cloud platform, SignalWire, FreeSWITCH can connect seamlessly to external networks and adapt to any scale of operation. To simplify your initiation, a pre-configured virtual machine come complete with comprehensive written and video tutorials, allowing you to get started quickly—just install VirtualBox and you will be set up in no time. For those with advanced programming skills, there are detailed instructions available to compile FreeSWITCH from source or explore other manual installation methods. Additionally, if you have a Debian instance available, you can find thorough guidance on how to install our packages from the provided link, ensuring versatility in your approach to utilizing FreeSWITCH. This platform truly empowers both beginners and seasoned developers alike, making telecommunications more accessible than ever.

Founded in January 2015, sipXcom emerged from a fork of the sipXecs project, initiated by the eZuce, Inc. development team. The sipXecs and SIPfoundry communities were struggling to expand their developer base due to a limiting contributor agreement, prompting the creation of sipXcom, which features an open contribution model. The source code for sipXcom is licensed under the copyleft-friendly AGLP v3 (Affero General Public License), ensuring greater flexibility for developers. Currently under development, SWARM is the codename for the upcoming iteration of the sipXcom and sipXecs projects, with a production launch expected in early 2017. This new platform will adopt a microservices-based architecture, enhancing scalability, reliability, and configurability beyond what sipX currently offers. SWARM is engineered to be compatible with any computing environment, including dedicated, virtual, or cloud servers, and also allows for hybrid setups that merge on-premise and cloud solutions. With these advancements, sipXcom aims to significantly improve user experience and functionality in the ever-evolving communication landscape.