UCaaS Architecture and When You Must Pay for Single Tenancy

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Unified Communications as a Service (UCaaS) solutions combine apps and services such as call, chat, video, and video conferencing into a single cloud-based platform. It’s an all-encompassing, easy-to-set-up communications solution.

UCaaS comes with tools like VoIP phone systems, instant messaging, email, online meetings, conferencing, calendars, screen sharing, and scheduling.

All you really need to adopt UCaaS is an internet connection and credentials. However, UCaaS solutions differ widely from each other in terms of pricing, comms, and administrative capabilities.

Your choice of a UCaaS architecture can serve different bandwidths, and the infrastructure you decide on shapes how other elements—like access, security, and customization—are laid out and structured.

UCaaS market size bar graph in billions from 2020 to 2025 from Nextiva.

Key Concepts to Better Understand UCaaS Architecture

Although UCaaS has many moving parts working behind the scenes, the end product—what the average user can see—will be easy to use. UCaaS aims to streamline communication by being user-friendly and running invisibly.

Let’s go through some essential terms you need to know to be able to grasp UCaaS architecture and how hosting providers work:

  • Cloud infrastructure: The cloud is a series of hardware appliances and software stacks that you can link to through the internet so you don’t have to host applications on your servers.
  • On-premises: The classic way to host applications—in your own company and rack. When an architecture combines cloud and on-premises models, it’s called a “hybrid” model.
  • Data center: A data center is a physical location that is used to store computing hardware equipment. It contains all the infrastructure that IT systems need to work, such as servers, data storage drives, and network equipment.
  • Hypervisors: The software that makes virtualization possible.
  • Virtualization: A technology that runs virtual versions of physical hardware like servers and networks in a single appliance.
  • Tenant: In cloud computing, a tenant is a customer. There is a key difference between single-tenant and multi-tenant models.
  • Software instance: A software instance refers to a single occurrence of a software application running on a computer system or server. Each instance operates independently with its memory space and resources, even if multiple instances of the same software are running together.
  • Redundancy: Redundancy is a strategy to prevent data loss and downtime in case of a failure. If a server fails or a hard drive is wiped out, there’s a backup plan online.
  • Scalability: Cloud scalability in cloud computing refers to increasing or decreasing IT resources as needed. It’s very practical for businesses since they can add computing power in a pay-as-you-go model.

Types of UCaaS Architecture

UCaaS isn’t a static, one-size-fits-all solution. Rather, think of it as customizable and scalable.

When setting up your UCaaS, you’ll need to assess your budget and goals and think about how you want to integrate it with your existing system. Your choice of architecture will influence performance, security, overall user experience, and more.

There are three primary UCaaS architecture options to consider.

Single-Tenant UCaaS Architecture

This architecture means that your company won’t share hardware and software resources with anyone else. Even if it’s hosted outside your premises, this model ensures a private hosting plan so the single instance of the software runs on a dedicated cloud server for just one customer.

A single-tenant option can be hosted on-site and integrated with existing on-premises applications, too. With it, the service provider creates a tailored solution, which in turn offers a high degree of customization and personalized service.


  • Greater security. Data is physically isolated from other organizations, so the chances of having a data breach are very low. The healthcare and finance industries often choose this system for this reason plus the extra security measures, quick customer response time, and help with compliance.
  • Greater reliability. Your platform is separate from others and resources are available anytime, so your data is safe if another customer’s software instance goes down.
  • Customization options and added functionality. Clients get personalized, purpose-built software to fit their specifications.


  • Hard to make the most of it. Resources are often underutilized since there are as many software instances as customers.
  • Costly setup. Because there is no cost-sharing, the price of owning and maintaining this system can be high.

How to Know if Single-tenancy Is Right for You

Companies that use single tenancy are often responsible for clients’ personal information. They may operate in highly-regulated markets with strict compliance standards, such as HIPAA or GDPR. Healthcare organizations, government agencies, or financial institutions should consider it first.

Because the infrastructure and software instances are not shared, single tenancy frequently provides greater performance and confidentiality than shared infrastructure. It’s the smart option if you value dependability and need a better backup and easy restore. However, this model type comes with a steep price tag.

Overall, the single-tenancy solution is best for organizations that must prove to customers, investors, and regulators that they have tight control of digital assets.

Multi-Tenant UCaaS Architecture

Multi-tenant UCaaS clients join ways with multiple cloud customers, pooling resources by dividing up a single physical resource into virtually separate instances. You won’t know who your pool members are, nor will you have access to the others’ resources.

This means that numerous businesses share hardware—for instance, servers—that’s virtually set apart thanks to a hypervisor. This creates isolated tenant spaces within the same physical server. Regardless of how other tenants use their stacks, your provider will keep your data separate and push updates to your system.


  • Cost-efficient. Building and maintaining the system is cheaper thanks to shared infrastructure and platforms. Depending on your plan, you only pay for what you use and as you go.
  • Secure. If your provider has good cybersecurity protocols in place, your data will remain secure and encrypted with minimum IT requirements on your behalf.
  • Easy to get on board. This model lets you deploy it rapidly, so you can be up and running with minimum effort.
  • Easier scalability. Need more video conferencing seats? Easy. Multiple tenants can be accommodated within a single instance without altering the infrastructure much, whether it’s the vendor providing the infrastructure or the customers relying on it.
  • Minimal maintenance. Since the server belongs to the software provider, they perform centralized maintenance and updates.
  • Redundancy support. Whether it’s a temporary shutdown for maintenance or a major incident, providers often have redundancy and backup systems to ensure the service remains up and running.


  • Limited customization. In-depth customization is unavailable, since the hardware is picked by a vendor and its usage is arbitrarily allotted.
  • Vulnerability. Multi-tenant environments have multiple user access points, so the security protocols that ensure tenant isolation and data storage need to be top-tier in order to prevent unauthorized access.
  • System outages. If a technical problem occurs on the provider’s end, it can impact all tenants and hamper your availability, system upgrades, and other global processes. Some providers outsource their services to cloud providers—if any of the two fail, the tenant is left offline.

How to Know if Multi-tenancy Is Right for You

Multi-tenant plans are better suited for customers who are more focused on flexibility and scalability, want to streamline updates and maintenance, or are on a budget. By sharing costs between tenants, the system is accessible to businesses of all sizes, like startups and companies that constantly readjust their expenses.

Multi-tenancy is a widespread model that occurs outside UCaaS architectures with companies such as Netflix and Atlassian. Additionally, most companies that join a Microsoft Teams plan are on a UCaaS multi-tenant model.

Hybrid UCaaS Architecture

A hybrid architecture model typically refers to a mix of on-premises and cloud-based systems in cloud computing.

It lets organizations integrate their locally-hosted call center solution with a cloud-based chat application that works straight off the shelf. In the end, these models can help to expand or cut back communication services without a risky investment.


  • Mix-and-match. You can handle confidential data in a physically separate, on-premises service and run more experimental features on a scalable, multi-tenant system.
  • Security. The most sensitive applications can remain on-site or in a single-tenant model. Or, you can add layers of security to your premises at will.
  • Flexibility to scale up and down. Based on your requirements, businesses can handle sensitive aspects or information on-premises while moving less critical applications or microservices to the cloud.


  • Integrations can be tricky. With this architecture, integrations are easy to pitch, but they could operate slower than expected.
  • Maintenance. Since this model combines cloud with on-site applications, maintenance won’t be fully handled by your vendor. It will require support and maintenance by your own IT team.

How to Know if a Hybrid Tenancy Is Right for You

The hybrid approach can be ideal for businesses that have already made large investments in on-premises infrastructure or those that keep sensitive applications. It’s also a great way to start using a new UCaaS solution without ditching your current stack completely.

Still, you should consider the IT costs that could spring up from making an unprecedented integration. Since it’s your premises you’re working on, the only experts ready to provide support will need to be in-house.

Choosing Your UCaaS Architecture

Every UCaaS architecture works—it’s just a matter of checking how your industry adapts to it. Compliance and security are important for everyone, but some organizations only need to be GDPR-compliant, nothing more. Each company will have their own priorities depending on location, budget, and size.

Some might prefer an immediate transition to full cloud technology, while others might choose to remain entirely on-premise or opt for a hybrid setting at first. The key is to find a vendor that supports the shift you’re undergoing.

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