Compare the 8 leading unified communications providers

1. Alcatel-Lucent Enterprise (ALE) OmniPCX

ALE's unified communications products include OmniPCX Enterprise Communication Server for large enterprises. ALE is also one of the handful of vendors that offers a true end-to-end unified communications product. For those that wish to simplify the ongoing management and support of their unified communications platform, end-to-end options are worth looking into.

The OmniPCX platform is highly scalable, with users able to architect it to support multiple geographic locations while being managed by a centralized management interface. It's also a modular platform that lets companies select the components required to power their UC needs. This includes Session Initiation Protocol (SIP) endpoints, such as IP phones, video conferencing and softphone applications, as well as media gateways for connecting the UC platform to external entities and third-party services, ALE claims.

UC services can be deployed using dedicated hardware appliances or as VMs. Each UC server can support up to 15,000 extensions. The company can cluster multiple servers to support over 1 million extensions, if required. Finally, the OmniPCX platform offers unique mobility features, such as the OpenTouch Conversation application and native off-site mobility for multiple channels of communication with employees that are always on the go.

2. Avaya Aura

Another enterprise UC platform that offers end-to-end functionality from a single vendor is Avaya's Aura product. Avaya is a well-known name in the world of enterprise voice and UC. Aura Platform includes multiple communication components so companies of all sizes can use it. Avaya is a scalable and modular product, integrating voice, video, chat, file sharing, mobility and many more services.

Avaya Aura Communication Manager is the core component of the overall UC platform. It is what provides the foundation for delivering real-time voice, video, messaging, mobility and other UC services.

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 the termination of 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.

3. Cisco Unified Communications Manager

Cisco is heavily involved in enterprise infrastructure, including offering a complete, end-to-end unified communications platform known as Cisco Unified Communications Manager -- or CUCM for short.

CUCM comes in several different sizes that range from support for midsize businesses up to a few hundred users to large enterprises up to 100,000 users. While third-party SIP phones are a possibility in terms of desk phone connectivity, most opt to deploy one of Cisco's multiple lines of IP phones -- some of which include built-in video conferencing capabilities.

Cisco Unified CallManager forms the foundation of the overall CUCM platform. 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. Cisco also provides tight integration with its highly popular Webex online meeting services that can be deployed in a hybrid or fully public cloud architecture.

CUCM can accommodate mobile workforces with its softphone and IM applications, as well as secure connectivity into the UC platform using the Cisco Expressway platform. With Cisco Expressway, users can make phone and video calls directly from their softphone without the need of a VPN.

4. Microsoft Teams

Microsoft Teams is one of the better-known cloud-based enterprise UC platforms on the market today. Teams is fully integrated with Microsoft's overall Microsoft 365 SaaS offering. Thus, one way in which Teams stands out is that, if companies subscribe to Microsoft 365, they'll likely have a Teams license. Another major advantage of Teams 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. Therefore, if an organization's user base widely uses Microsoft 365 apps, it may want to consider Teams.

Teams' functionality includes team chat, file sharing, video conferencing and VoIP calling with public switched telephone network (PSTN) access. 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.

It should be noted, however, that calling features within Teams are somewhat limited. Therefore, if users need to heavily rely on voice communications and complex call routing scenarios, this may not be the best option for that company. Microsoft itself even promotes its Microsoft 365 Business Voice services as being "built for small and medium businesses." Thus, large enterprises are better off looking elsewhere.

5. Mitel MiVoice Business

Since the acquisition of ShoreTel in 2018, Mitel Networks Corp. has become a formidable opponent in the enterprise unified communications space for businesses both large and small. The MiVoice platform comes in several form factors that largely depend on the organization size 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 suitable for 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, while handling anywhere from 500 to over 100,000 users.

Companies can install the larger MiVoice platforms in a traditional sense using 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, the combination of appliance, bare-metal and virtual server deployments are possible. Thus, the options for physical deployment are plentiful.

Features of the MiVoice platform include enterprise-grade VoIP with all the typical corporate features, like voicemail, hunt groups and advanced call routing, video conferencing, team chat and file sharing, a comprehensive contact center add-on and seamless mobility functions through the use of Mitel mobile apps.

6. Mitel MiCloud

Mitel rebranded ShoreTel's cloud-based UC platform as part of the acquisition. Additionally, the vendor has spent a great deal of time and money refining the product so that it can better compete with other cloud UC platforms, including Microsoft Teams. MiCloud is mostly aimed at the SMB market, but even large enterprises could adopt MiCloud if they chose, as there is no limitation to the number of subscriptions that companies can purchase.

The platform includes some different features, such as MiCloud Connect CX, a customer experience platform to create a uniform and easy-to-use communications omnichannel for business customers. It also offers MiCloud Connect Contact Center, a comprehensive cloud-hosted call center platform for businesses that require it. Finally, MiCloud Connect integrations include several pre-made, third-party interoperability features that enable users to share and contribute information.

When looking at what MiCloud offers, companies will notice two different architecture options.

The first option is MiCloud Connect. This is Mitel's fully cloud-managed cloud UC platform, which includes enterprise voice, video, messaging, presence, file sharing and even contact center services. Target businesses include SMBs that are seeking a streamlined UC platform that doesn't take a tremendous amount of in-house IT staff to manage. The other target market is businesses with many mobile users. Because MiCloud Connect resides fully in the public cloud, users can connect from anywhere at any time without the need to connect back to a corporate network.

MiCloud Flex is the other architecture option. The vendor designed this product for large businesses that require more feature-rich capabilities and customizations that the fully cloud-based MiCloud Connect service cannot offer. This is especially true for businesses that require complex contact center functionality. MiCloud Flex is a hybrid cloud platform that delivers some services in Mitel's public cloud, while locally delivering other services on the corporate LAN.

7. NEC Univerge 3C

Univerge 3C is NEC Corp.'s unified communications platform targeting enterprises both small and large. Univerge 3C is a single software application 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. Thus, for organizations that only manage Windows Server OSes in their data center, this product may be appealing.

Another thing to consider with Univerge 3C operating on the Windows Server OS is that it fully integrates with Microsoft Exchange and Active Directory to ensure compatibility, operability and enhanced productivity.

NEC can deliver Univerge 3C as a hardware appliance or simply sell the software for companies to install on x86 bare-metal hardware or in a VM environment. Organizations 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. So, 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 application features as well. For one, the UC client supports a range of devices, such as smartphones, PCs and tablets. NEC offers the same UI across all devices, creating an unvarying experience from one device to another.

The UC client application includes capabilities such as VoIP, team chat, video conferencing, real-time presence and several Microsoft Outlook integrations.

8. Unify OpenScape Voice

Atos 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;
• unified communications;
• mobility and video;
• Xpressions for messaging;
• contact center; and
• 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. Additionally, the company claims that the product can support up to 100,000 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 client, users can perform video calls, access presence services and conference calls, set their preferred device and much more.

Like many other enterprise-grade unified communications 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.