What is cloud migration? Cloud migration 101

More and more enterprises are moving their communications stack to the cloud. Here's what you need to know.
enterprise building and server in cloud

The Great Cloud Migration is underway. 

Are you ready?

According to research by NoJitter, there’s been a 240% increase in UCaaS adoption within the last two years alone, fueled by the pandemic’s impact on working patterns. In fact, we’ve been told by contact center leaders across the country that the pandemic forced them to make 5 years of progress in modernizing their contact center.

Your organization’s future lies within the cloud, and the path to get there is evolving each day. We’re here to help you get there quickly, simply and on your terms so you’re ready for whatever the future holds.

No matter what platform you’re migrating to, or where you’re migrating from—this guide will equip you with real takeaways and important details to help you with your own migrations. 

What is cloud migration?

First, let’s define some terms. What exactly is cloud migration? 

Cloud migration is when a business moves its operations from an owned, on-premise infrastructure model to a hosted,  “cloud” model.  Cloud migrations can either be about moving from one cloud location to another, or moving on-premise infrastructure and data to the cloud. Just like where a physical moving home involves moving boxes, a cloud migration involves moving data and systems—–and, like the same as a physical move, you need to do a lot of planning and prep work.

But why are businesses moving from legacy, on-premise equipment to cloud infrastructure? 

Legacy infrastructure is older software or hardware that’s still in use. Sometimes, legacy systems run slower and act unreliably. 

That’s not to say that legacy systems are nothing but cons. Physically owning your platform’s infrastructure and being able to make changes in real time provide a desirable level of control. Because of this, some favor a hybrid model, so you can retain the benefits of both on-premise and cloud infrastructure. 

Moving to a modern system that promises security, speed, and reliability is one of the many reasons so many have started migrating to the cloud. 

What are the benefits of cloud migration?

Long answer: there are many benefits gained when migrating to the cloud. The main four are improved scalability, performance, flexibility, and lower overhead costs. 


Migrating to the cloud means your company will have far fewer growing pains. Cloud computing can support more users and larger workloads than on-premise infrastructures. Your users can also work from anywhere! Being off-prem also gives you the ability to integrate with third-party software (like call verification or bio authentication) with ease.


Though this doesn’t apply to all businesses, cloud migrations often lead to better customer user experience and overall performance. Jitter and latency become much less of an issue, as data doesn’t have to travel as far from the cloud as it would from on-premise equipment to reach users. 


Employees, customers, and all other users can access cloud data anywhere and everywhere. This is one of the biggest appeals of cloud computing; it’s so much more flexible than on-premise equipment. This makes it much easier for businesses to expand to new areas and reach international audiences.


Post-migration, you don’t have to worry about IT operational or infrastructure spend. This is because cloud providers will handle any necessary upgrades or maintenance to the cloud and you’re outsourcing non-revenue-generating work.

Access to better tools

A cloud migration also means you’ll have access to a new range of tools that were developed cloud-first. 

Lower overhead

Unlike on-premise systems, you don’t have to worry about the hardware of cloud infrastructure. You’ll be able to save so much time and resources!

How does a cloud migration work?

Before we go into more detail about the benefits of cloud migration, let’s discuss how a cloud migration works. 

Picking your communications software before migrations seems like the obvious first step. But in reality, you don’t need to know which UCaaS or CCaaS platform you want just yet. 

Instead, you should focus on picking the right carrier, and you can move to and around the communications cloud without disruption (or migraines). 

At a glance, your migration should look something like this: 

  1. Decide on dates and goals–when do you want to have this migration finished?
  2. Unbundle your current communications platforms and carrier services.
  3. Audit your current unified communications and contact center tech stack.
  4. Replicate existing databases as a security measure.
  5. Orchestrate your migration based on the needs of your organization with software-powered porting tools.
  6. Test your voice and emergency services.  
  7. Leverage software agility and platform openness to integrate critical CPaaS capabilities at the carrier level.
  8. Move your users to the cloud in real-time with APIs and software.

There are many steps along the way to the cloud. Every single office, setup, and local SIP trunking provider you have in your comms stack creates one more layer of complexity. So if you’re a global enterprise, there are many, many more challenges to navigate in your move.

Thankfully, this is what Bandwidth does every single day. We’re going to get seriously practical and share some thoughts around how our Global 2000 customers have made their migrations a little less painful.

Beyond seeing improvements in security, speed, and reliability, do the benefits outweigh the risk when migrating to the cloud? 

Short answer: yes. 

What are the biggest challenges of migrating to the cloud?

We’ve all had to move at some point in our lives–be that moving from one apartment to another, or a full-on cloud migration. Both come with their unique difficulties. And unfortunately, moving to the cloud adds new and different challenges. 

You will likely face at least one of the following challenges: 

  • Disjointed SIP trunking providers that connect to your PBXs distributed all across the globe
  • Regulatory challenges and concerns around RAY BAUM’s Act and Kari’s Law in the U.S., and the evolving changes globally in the industry and applicable laws
  • Complex contact center configurations and third-party integrations to replicate your on-prem setup 
  • Compromised data integrity can be an issue with any data transfer. Always confirm that data is intact and secure. Checking for leaks is especially important
  • New realities of the hybrid workforce and work-from-anywhere models
  • Holdouts on legacy hardware that are delaying migrations

Communications complexity is already starting to add up, and this “simple” cloud future feels like an experience that’s just not quite what it was made out to be. Still, in order to deliver a positive customer (and employee) experience, moving your communication solutions to the cloud is a requirement.

What’s the best migration strategy?

According to Gartner, there are 5 migration strategies you can try when moving to the cloud. These are known as the “5 R’s”. Starting with “rehost”, each proceeding strategy allows a little more customization and change from your initial framework. 

#1: Rehost

Rehosting will give you the same system, just in the cloud. This is a strategy commonly used by Infrastructure-as-Service (IaaS) providers. 

#2: Refactor

This strategy will let you use pre-established code and frameworks, but old applications will be run on a new Platform-as-a-Service (PaaS) provider platform.

#3: Revise

This strategy involves the code and/or framework being expanded upon or rewritten. Deployment involves refactoring or rehosting (as mentioned above). 

#4: Rebuild

Rebuilding is even more in depth. This process usually involves the application being completely rewritten. Though this involves far more work, it means updated systems can get a fresh start. 

#5: Replace

If you’re tired of your old system and you want to start completely anew, you can just start with a new application. Replacement involves switching to a pre-built SaaS (software as a service) application, which can be purchased from a third party. 

What’s the best deployment strategy?

There are a lot of choices to make when undergoing a cloud migration. Beyond choosing the strategy to make the move, your business should also decide what you want your cloud deployment to look like. Consider any of the following: 

Single cloud

This deployment method involves deploying from only one cloud provider. Cloud providers can offer either public or private clouds. Public clouds are shared between businesses. 

Hybrid cloud

A hybrid cloud deployment method means a mix of environments. This might look like a combination of public and private cloud spaces are used, or the business could use a mix of on-premise data centers and cloud environments. This deployment method must be handled carefully to communicate across all server functions properly. 


A multi-cloud method is a deployment strategy that uses two or more public clouds. This strategy might appeal to you because it can be a very cost-effective method. 

Still want some help? Check out these three tips:

Tip 1: Audit your infrastructure

An important step that we can’t do for you (but we can walk you through and create joint project plans depending on the complexity of your move) is a comprehensive communications analysis. 

Assess your current infrastructure so that you have the fullest picture of what you need to migrate. A few examples include: 

  • Have you taken an inventory of your users and phone numbers? This seems obvious, but many enterprises that have grown through mergers and acquisitions have phone numbers in different area codes.
  • Have you mapped your IVR Call flows? Figuring this out before you start your migration is critical to CX and EX. Start by locating your IVR recordings or making new ones. Then, document those IVR flows so you have everything you need to set up your new cloud platform.
  • Have you mapped your Network Topology? This will help you configure emergency address network elements, like wireless access points, ports & switches — which will be necessary for Dynamic E911 for Microsoft Teams.

Tip 2: Identifying the right SBC configuration for your needs

If you’ve chosen BYOC for your migration, assess if you want to manage your own Session Border Controller (SBC) or have it hosted by your carrier. Whereas calling plans give you an all-in-one solution, unbundling telecom for added control means you might have to think about SBC requirements carefully. 

When Microsoft Teams first launched Direct Routing, their whole model was based on companies managing their own SBC, and plugging Teams into that.

Since then, more and more businesses want a hosted SBC. In fact, it was so popular that Microsoft released Operator Connect, which gives customers the option to be fully in the cloud with SBC-as-a-Service provided by their carrier alongside PSTN connectivity.  

Here are four reasons why a hosted SBC might be the right choice for your organization: 

  1. You’re choosing between a major, long-term investment versus an operational, day-to-day investment model to lower spending on equipment.
  2. It’s much faster to deploy a hosted solution so you can keep up with timelines and evolving communications needs. 
  3. It reduces the need for specialized expertise and investments (VoIP engineering certifications, and anything else required to manage your own SBCs in-house).
  4. It drastically simplifies your global infrastructure management. More and more large enterprises with complex global infrastructure want a hosted solution globally because managing telephony infrastructure across multiple continents is exponentially complex.

Once you’ve audited your communications stack and evaluated if you should or shouldn’t outsource your SBC, look for certified SBC providers that work with your desired UCaaS or CCaaS platform of choice.

Tip 3: Test your SIP and emergency services carefully

We can’t stress this enough: Test, test again, and test some more, especially when it comes to emergency calling. 

For SIP, make sure you perform voice testing across inbound, outbound, IVR call flows, holds, transfers, and failovers. For emergency services, make sure you: 

  • Test endpoints with 933 to cut down on live 911 calls to PSAP
  • Test live notifications at the time of each 911 call 
  • Live 911 testing of primary and secondary SBCs
  • Notify PSAPs in advance of live testing

We set up 933 call routing policies so you can verify location information without having to perform live 911 testing. And with new regulations like Kari’s Law, which requires notifications at the time of 911 calls, and RAY BAUM’s Act, which requires address line 2 information to be included at the time of each call, it’s challenging to comply. 

We’re not here to give legal advice, and you should consult with your legal team to map this out. Correctly routing 911 calls is incredibly important to the wellbeing of your employees. It’s worth the time and energy because it can have a potentially life-saving impact.

To learn more about 911 testing, check out our complete 911 testing guide.

How will cloud migration change in the future?

The future is in the cloud. As we race toward the future, our telecommunications experts expect that more and more companies will be leaving on-premise equipment behind as they start the migration. 

Still, the world of telecom changes yearly. Our experts have done extensive research to find answers as to how the enterprise landscape has been changing. 

How to make cloud migration easier

Cloud migration is a headache waiting to happen. Sure, things will be easier once you’re on the other side–the hard part is getting there with all your data (and sanity) in one piece. 

Bandwidth can help. 

Our experienced telecom experts have years of expertise with guiding migrations to the cloud. Explore your options with our wide, award-winning suite of tools and BYOC offerings

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