10 top unified communications providers for 2025
Compare the latest architecture developments, as well as advanced communications and collaboration UC platform features, offered by the leading unified communication providers.
The enterprise unified communications market continues to evolve. Whether that evolution includes architecture advancements using the cloud or new communications and collaboration features, it's essential to know the options and understand which UC platforms are best.
Informa TechTarget editors researched and identified some of the leading UC platforms and vendors and summarized their most prominent features so businesses can make informed decisions. Based on this analysis, here is an unranked, alphabetical list of 10 top platforms.
1. 8x8 X Series
Dubbed "experience communications as a service," this fully cloud-deployed system delivers UC and contact center services under a single platform. Experience Communications Platform is ideal for businesses that have large numbers of remote workforces, many of which operate in call center and contact center roles. 8x8 Engage extends the functionality of the UC platform with AI and omnichannel support, designed to improve customer experience beyond traditional contact center capabilities.
UC-specific features for business phone users include unlimited calling; text messaging; fax; voicemail; call recording; call forwarding, transfer and parking; directory assistance; and call analytics. The service can be purchased as a monthly or annual subscription and is offered in two tiers for UC services:
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- X2 includes unlimited calling to the U.S., Canada and 12 additional countries, video conferencing for up to 500 participants, team chat and Microsoft Teams integration.
- X4 includes everything in the X2 tier, unlimited calling to 48 countries, receptionist capabilities and advanced analytics, as well as call monitor, whisper and barge features.
2. Alcatel-Lucent Enterprise OmniPCX
OmniPCX Enterprise Communication Server is geared toward large enterprises. Alcatel-Lucent Enterprise (ALE) is one of a handful of vendors that offers a true end-to-end UC product to simplify the ongoing management and support of its UC platform.
OmniPCX is highly scalable. Users can architect its centralized management interface to support multiple geographic locations. Its modular design lets companies select the components they need to power their UC requirements, including Session Initiation Protocol (SIP) endpoints, video conferencing and softphone applications, as well as media gateways to connect the UC platform to external entities and third-party services, according to ALE.
UC services can be deployed as VMs or by using dedicated hardware appliances. Each UC server can support up to 15,000 extensions. If required, ALE can cluster multiple servers to support more than 1 million extensions. OmniPCX also offers mobility features, such as the ability to have unique public switched telephone network (PSTN) numbers among business phones, mobile headsets and softphones. Hybrid cloud connectivity is available using ALE's Rainbow communications platform.
3. Avaya Aura
Avaya offers end-to-end UC functionality through its on-premises Aura platform, now part of the company's Communications & Collaboration Suite, which incorporates contact center as a service and other collaboration tools. The company has integrated the telephony platform with cloud technologies, such as Avaya Cloud Office by RingCentral for businesses migrating to hybrid cloud environments.
The Aura platform includes multiple communication components so businesses of all sizes can use it. Aura is scalable and modular, integrating voice calls, video, live chat, file sharing, mobility and other services. The platform is underpinned by Aura Communication Manager, which delivers more than 700 real-time voice, video, messaging, mobility and other UC services.
Aura Communication Manager is responsible for registration and maintenance of all SIP endpoints, call routing, call queuing, prioritization of voice and video calls, and more. Avaya Aura also offers built-in conferencing and contact center platforms -- a good option for businesses with call centers and challenging conferencing requirements.
Other Aura components include a session manager to help manage VoIP routing, SIP trunking and user and group profiles; a session border controller (SBC) for terminating external SIP trunks; a presence server to help identify locations and statuses of employees; and an application enablement services server that offers advanced APIs and web services for third-party integrations. The company has partnered with Zoom to offer Aura and Zoom Workplace collaboration tools, including AI Companion.
4. Cisco Webex
Cisco Unified Communications Manager (CUCM) is an end-to-end UC platform. It's tightly integrated with Cisco's communications and collaboration suite, Webex, and can be deployed in a hybrid or fully public cloud architecture. Webex Suite supports calling, video conferencing, messaging and file sharing and provides AI functionality.
CUCM can be tailored to support businesses ranging from a few hundred to 100,000 users. Businesses can opt for third-party SIP phones, but most deploy one of Cisco's IP phones, some of which include built-in video conferencing capabilities.
Cisco Unified CallManager is the platform's foundation. It provides basic functionality, such as IP phone registration, call control, call routing and session management. Other features require add-on platform servers, including voice messaging, IM and enterprise video conferencing.
CUCM accommodates mobile workforces with enhanced extension mobility. CUCM can also integrate with Cisco's hosted collaboration platform or Webex Calling for branch offices and remote workforces. Webex Suite supports Google Workspace, Microsoft 365 and Salesforce.
5. Microsoft Teams
Microsoft Teams offers a full range of UC services, including team chat, file sharing, video conferencing and VoIP calling with PSTN access. Businesses that subscribe to Microsoft 365 likely already have a Teams license.
Teams natively works with many of the other Microsoft 365 applications, such as Outlook, OneDrive, Excel, PowerPoint, SharePoint and OneNote. Microsoft's Copilot AI functionality is designed to help automate tasks and improve collaboration.
The addition of PSTN voice licenses, known as Microsoft 365 Business Voice, gives users a cloud-managed, enterprise-grade voice and audio conferencing platform, making it a low-cost option for an organization's UC needs.
6. Mitel MiVoice and MiCollab
Mitel Networks has become a formidable player in the enterprise UC space for large and small businesses. The MiVoice portfolio comes in several on-premises or cloud deployments geared to an organization's size, geographic location and number of users. The company bolstered its UC and contact center capabilities when it acquired Unify (OpenScape Voice) from Atos SE. MiVoice offers voice and communications services, and MiCollab provides team messaging, video conferencing and collaboration tools.
Fully SIP-based MiVoice enables the use of Mitel-branded phones or several third-party SIP phones. On the lower end of the spectrum is the MiVoice Connect on-premises appliance for smaller businesses or branch offices staffed with as few as five employees. For much larger businesses, Mitel offers its flagship MiVoice MX-ONE platform that can span multiple sites and geographic locations, handling anywhere from 500 to more than 100,000 users.
Businesses can choose how they want to deploy the platform. Larger MiVoice platforms can be installed through proprietary appliance hardware directly from Mitel. Alternatively, the UC OS and services can be installed on standard x86 bare-metal servers or as a VM -- on-premises or in a private or public IaaS cloud. For multiple server environments, businesses can combine appliances, bare metal and virtual servers.
The Mitel UC platform offers enterprise-grade VoIP with all the typical corporate features, including voicemail, hunt groups and advanced call routing, video meetings, team chat and file sharing, a comprehensive contact center add-on and mobility functions through the use of Mitel mobile apps.
Mitel supports the RingCentral Mobile Voice Phone (MVP) system, now called RingEX, with its CloudLink technology, but the partnership is no longer exclusive. The company announced a strategic partnership with Zoom and its Zoom Workplace collaboration tools -- meetings, phone and AI Companion -- to broaden its UC-as-a-service offerings.
7. Mitel OpenScape Enterprise
OpenScape Enterprise comprises a wide range of enterprise communications options for on-premises, cloud and hybrid environments. The main components include OpenScape Voice, Media Server, UC, mobility and video meetings, Xpressions for messaging, contact center, and SBC for SIP trunking.
OpenScape is 100% SIP-compatible; businesses can use most enterprise-grade, SIP-compatible phones. The OpenScape Voice platform features sizable redundancy and scalability capabilities. Mitel claims the product can support up to 500,000 users in a multisite deployment. OpenScape Voice is delivered to customers as a Linux-based VM that must be installed in a hypervisor environment. Mitel doesn't offer appliances, nor does it support bare-metal installs.
With OpenScape UC, employees can connect with each other or customers via a desktop client, web client, voice portal or mobile client. Advanced UC applications, such as Mitel's mobile client, can operate within OpenScape UC to provide mobility features. With the mobile device client, users can perform video calls, access presence services and conference calls, set their preferred device and more.
Like many other enterprise-grade UC platforms, Mitel's OpenScape Voice offers contact center features for businesses that require call center capabilities. OpenScape Contact Center is designed for midsize to large contact centers supporting up to 7,500 active agents in a multiserver deployment model or up to 1,500 active agents on a single server.
8. NEC Univerge 3C
NEC Corp.'s Univerge UC platform is geared to small and large enterprises. It's a single app that provides businesses with enterprise-class VoIP, voicemail, unified messaging, team chat, file sharing, video conferencing and more.
Unlike most UC products, the Univerge 3C platform runs on Windows Server. Most other vendor products operate in the cloud or use Linux-based OSes. Univerge 3C fully integrates with Microsoft Exchange and Active Directory to ensure compatibility, operability and enhanced productivity.
Univerge 3C can be deployed as a single on-premises hardware appliance or through a managed or hybrid cloud. Businesses that choose to run the platform on-premises or in a hybrid environment can use this platform in Hyper-V and VMware hypervisors. According to NEC, each physical or virtual server supports up to 1,500 devices, with a total of 20 servers deployed in the network; at maximum capacity, it can support up to 30,000 devices, giving it the ability to cover large, global enterprises.
Univerge 3C offers several desktop and mobile device application features as well. The UC client supports a range of devices, such as smartphones, PCs and tablets. NEC offers the same UI across all devices, creating a uniform experience throughout. The UC client application capabilities include VoIP, team chat, video conferencing, real-time presence and several Microsoft Outlook integrations.
9. RingCentral RingEX
RingCentral's UC platform offers messaging, video conferencing and phone capabilities. RingSense AI functionality adds intelligence capabilities across its cloud-based communications products. The SaaS-based RingEX business phone system, formerly RingCentral MVP, is offered in three service tiers, billed either monthly or annually:
- Core. Each user gets access to unlimited U.S. and Canada calling, a business or toll-free phone number, text messaging, 100 toll-free inbound minutes, visual voice level, multilevel interactive voice response and shared line capabilities.
- Advanced. In addition to the features found in the Core tier, toll-free minutes are raised to 1,000. Business features such as extension calling, receptionist and administrator console, automatic call recording, advanced call routing and hot desking capabilities are available.
- Ultra. Users get access to everything in the Advanced offering, in addition to device analytics and alerts, business analytics, unlimited file storage and up to 10,000 inbound toll-free minutes each month.
Add-on features are also available to all tiers, including RingCentral Webinar, conference room equipment licenses, international phone numbers and push to talk. Business Phone can also be integrated into other RingCentral services, such as RingCentral Contact Center or RingCX. The company has partnered with Avaya and Mitel to integrate its cloud services.
10. Zoom Workplace
The Zoom UC platform consists of video conferencing, telephony, chat and collaboration tools. SaaS-based Zoom Phone, which integrates PSTN calling capabilities, is offered in three tiers:
- United States and Canada Metered is a pay-as-you-go model that includes metered domestic U.S., Canada and international calling, text messaging, access to U.S. and Canada phone numbers, and multi-device use, including supported desk phones and smartphone and tablet apps.
- United States and Canada Unlimited includes everything in the metered tier, with the addition of unlimited U.S. and Canada calling and metered international calling. An optional add-on is available for unlimited calling to 19 different countries.
- Global Select is the top tier. It's identical to the unlimited plan with the added option to deploy PSTN numbers to users who reside in countries outside the U.S. and Canada.
Zoom Workplace also includes third-party integration with popular business applications, such as Salesforce, Slack and Microsoft 365. Toll-free numbers are also available. Zoom's Omnichannel Contact Center service is an option for businesses that serve inbound and outbound call centers. Zoom Workplace offers AI functionality and other enhanced tools for team collaboration in hybrid environments.
Editor's note: This article was updated in January 2025 to reflect the latest developments in UC provider platforms.
Andrew Froehlich is founder of InfraMomentum, an enterprise IT research and analyst firm, and president of West Gate Networks, an IT consulting company. He has been involved in enterprise IT for more than 20 years.
Kathleen Richards is a freelance journalist and industry veteran. She's a former features editor for TechTarget's Information Security magazine.
