Compare the 10 leading UC providers in 2024

1. 8x8 Experience Communications Platform

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 or contact center roles.

UC-specific features for business phone users include the following:

• Unlimited calling.
• Text messaging.
• Fax.
• Voicemail.
• Call recording.
• Call forwarding/transfer/parking.
• Directory assistance.
• Call analytics.

The service can be purchased as a monthly or annual subscription and is offered in two tiers for UC services:

• X2. This plan includes unlimited calling to the United States, Canada and 12 additional countries, video conferencing for up to 500 participants, team chat and Microsoft Teams integration.
• X4. This plan includes everything in the X2 tier, unlimited calling to 48 countries, receptionist capabilities, advanced analytics and call monitor, whisper and barge features.

2. Alcatel-Lucent Enterprise (ALE) OmniPCX

OmniPCX Enterprise Communication Server is geared to large enterprises. ALE is one of a handful of vendors that offers a true end-to-end UC product. For those who wish to simplify the ongoing management and support of their UC platform, end-to-end options are worth looking into.

OmniPCX is highly scalable, with users able to 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. This includes Session Initiation Protocol (SIP) endpoints, such as IP phones, 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 using dedicated hardware appliances or as VMs. Each UC server can support up to 15,000 extensions. If required, ALE can cluster multiple servers to support more than 1 million extensions. Finally, OmniPCX offers unique mobility features, such as the ability to have unique public switched telephone network (PSTN) numbers between business phones, mobile headsets and softphones. Hybrid cloud connectivity is also available using ALE's Rainbow communications platform.

3. Avaya Aura

Avaya is another vendor offering end-to-end UC functionality through its Aura Platform. Aura Platform includes multiple communication components so companies of all sizes can use it. Aura is scalable and modular, integrating voice calls, video, live chat, file sharing, mobility and many more 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 registering and maintaining all SIP endpoints, call routing, call queuing, prioritization of voice and video calls, and much more. Avaya Aura also offers built-in conferencing and contact center platforms. This is a good option for organizations with call centers and challenging conferencing requirements.

Other Aura components include a session manager to help manage voice over IP (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.

4. Cisco Unified Communications Manager

Cisco Unified Communications Manager (CUCM) is another end-to-end UC platform.

CUCM can be tailored to support businesses ranging from a few hundred to 100,000 users. Companies 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. CallManager 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 is tightly integrated with Cisco's online meeting app, Webex, and can be deployed in a hybrid or fully public cloud architecture.

CUCM version 12.5 accommodates mobile workforces with enhanced extension mobility. Additionally, CUCM can integrate with Cisco's hosted collaboration platform or Webex Calling for branch offices and remote workforces.

5. Microsoft Teams

Microsoft Teams is another platform that offers a full range of UC services, including team chat, file sharing, video conferencing and VoIP calling with PSTN access. A particular selling point is Teams' integration with Microsoft's 365 SaaS offering. Companies that subscribe to Microsoft 365 likely already have a Teams license.

Another major benefit is that it's designed to natively work with many of the other Microsoft 365 applications, such as Outlook, OneDrive, Excel, PowerPoint, SharePoint and OneNote. Those organizations that significantly rely on Microsoft 365 apps may want to consider Teams.

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

Mitel Networks has become a formidable challenger in the enterprise UC space for businesses both large and small. The MiVoice portfolio comes in several on-premises or cloud deployments geared to an organization's size, geographic location and number of users.

The fully SIP-based product 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.

Companies 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 -- either on-premises or in a private or public IaaS cloud. For multiple server environments, companies can combine appliances, bare-metal and virtual servers.

MiVoice offers enterprise-grade VoIP with all the typical corporate features, like 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.

7. NEC Univerge 3C

NEC Corp's Univerge UC platform is geared to both small and large enterprises. It is a single app that provides organizations with enterprise-class VoIP, voicemail, unified messaging, team chat, file sharing, video conferencing and much more.

Unlike most UC products in this roundup, the Univerge 3C platform runs on Windows Server. All other vendor products operate either in the cloud or use Linux-based OSes. For organizations that only manage Windows Server OSes in their data centers, this product may be appealing.

In addition, 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. Organizations that choose to run the platform on-premises or in a hybrid environment can use this product in both Hyper-V and VMware hypervisors. According to the company, 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 includes capabilities such as VoIP, team chat, video conferencing, real-time presence and several Microsoft Outlook integrations.

8. RingCentral Business Phone System

RingCentral's SaaS-based Business Phone System is offered in three service tiers, billed either monthly or annually. The three service tiers are:

• 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, multi-level IVR and shared line capabilities.
• Advanced. In addition to the features found in the Core tier, toll-free minutes are raised to 1,000 and business-rich features such as extension calling, receptionist/admin 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/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, among others. Business Phone can also be integrated into other RingCentral services, such as RingCentral Contact Center or RingCX.

9. Unify OpenScape Voice

Now part of Mitel, Unify's on-premises UC platform -- OpenScape suite -- offers a wide range of enterprise communication options. The main components include the following:

• OpenScape Voice.
• Media Server.
• UC.
• Mobility and video meetings.
• Xpressions for messaging.
• Contact center.
• SBC for SIP trunking.

OpenScape is 100% SIP-compatible. Thus, companies can use most enterprise-grade, SIP-compatible phones. The OpenScape Voice platform features sizable redundancy and scalability capabilities. Unify claims the product can support up to 500,000 users in a multisite deployment.

From a deployment standpoint, OpenScape Voice is delivered to customers as a Linux-based VM that must be installed in a hypervisor environment. Unify does not 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 Unify's mobile client, can operate within OpenScape UC to provide rich mobility features. With the mobile device client, users can perform video calls, access presence services and conference calls, set their preferred device and much more.

Like many other enterprise-grade UC platforms, Unity's OpenScape Voice product 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.

10. Zoom Phone

SaaS-based Zoom Phone, which integrates PSTN calling capabilities, is offered in three tiers:

• United States and Canada Metered. A pay-as-you-go model that includes metered domestic U.S., Canada and international calling, SMS/MMS messaging, access to U.S./Canada phone numbers and multi-device use including supported desk phones and smartphone/tablet apps.
• United States and Canada Unlimited. This service tier includes everything in the metered tier, with the addition of unlimited U.S./Canada calling and metered international calling. An optional add-on is available for unlimited calling to 19 different countries.
• Global Select. The top tier is identical to the U.S. and Canada Unlimited plan, with the addition that PSTN numbers can be deployed to users that reside in countries outside of the United States and Canada.

Zoom Phone 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 also an option for businesses that serve inbound and outbound call centers.

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.