Anatomy of a Design: Moving applications to the cloud

In our last post about IT infrastructure design, we considered the layout of a local network based on the requirements of a small, hypothetical law firm. In this post, we’ll illustrate how cloud applications can support this firm’s needs.

Migration or SaaS? Pick one.

Remember, our law firm is using some of the most common applications for billing and invoicing, accounting, document management, case and client management, email and Internet, and general project management. Let’s examine how to fulfill these requirements by embracing the cloud.

Firms wishing to use applications in the cloud have two basic options. The first is simply migrating applications that were originally purchased for use on a local server into the cloud. This is usually done through one of the major cloud provider platforms, such as AWS or Microsoft Azure.

infrastructure design


While straightforward, it requires some effort to properly size the virtual servers needed to support the firm’s applications. Services like Cloudamize and RightScale analyze an organization’s current application workloads, evaluate the costs of migrating to various cloud providers, and properly size cloud resources to avoid overpaying. A well-designed move is critical to avoid potential downtime and lost revenue.

The second option is to use Software as a Service (SaaS) — applications that already exist in the cloud. This option relates more to how an application will be used within the firm, what process it will augment or even replace, and who will be responsible for administration. Some cloud applications are complete turnkey firm management applications, and offer modules that address all the functions outlined in our list above.

Imagine that our law firm falls into either of two buckets – an established firm or a startup. The options for either situation remain the same (SaaS, cloud-based, or on-premises), but the path to migration will differ. We should note, however, that the best option for the firm in each example may not be the easiest, depending on costs and other firm-specific requirements.

Let’s begin with the established firm, which has applications already on-premises; we’ll call this a brownfield deployment. In this use case, a SaaS solution may prove the most difficult migration because data must be exported, which may require additional support and troubleshooting. The difficulty of a migration diminishes when a cloud-based solution is adopted, and it continues to drop if on-premises hosting is chosen.

Next, let’s imagine the firm is new, and only recently began working with clients (a greenfield deployment). In this case, an on-premises solution is the most difficult because it would require managed services, dedicated staff, and local deployment of applications. In contrast, a monthly subscription to SaaS application would be the easiest, since there’d be little in-house management required and almost no work to stand up the environment.

Here’s a breakdown of each firm’s options:


No matter which deployment option the law firm selects, it will need to move its data from one application to another or move its applications from one place to another – either between clouds or from on-premises into another cloud. Before migrating, here are some questions to ask about the application provider or cloud service:

  1. How easy is it to move data/applications into and out of the cloud/SaaS application?
  2. Does the application or cloud provider offer any services to assist with the migration?
  3. What training is required/available for the cloud service and/or application?
  4. Does the application provider support standard data import and export formats?
  5. Is billing done monthly or yearly? Are there any discounts or savings for longer contracts? (Be careful not to sign up for too long a contract before trying the application or service.)

Prior to moving to the cloud, it’s extremely important to right-size the environment, or the cloud could be more expensive than an on-premises solution. Once all of these decisions have been made and the proper size for the new environment has been determined, develop a plan for the overall migration with milestones and a project manager (typically internal staff) assigned to follow up on all tasks. Even if the manager lacks experience, having one person that works in the firm manage this will insure a much higher chance of success.

Understanding the network

Whether hosted or SaaS, cloud applications don’t require much in terms of design. However, one aspect of the firm’s infrastructure does need to be addressed: the network.

Specifically, a strong resilient connection to the Internet is critical to ensure accessibility to the cloud applications.

Figure 1

Figure 1

Note in Figure 1 the WAN connections (marked by a callout for ISP [1] and [2]). We have replaced our initial network switches with two highly available next-generation firewalls that support WAN access, and provide a secure VPN connection to the SaaS applications to prevent intrusion.

Choose-ISP-ProviderWe still need a cloud service to manage the firm’s IP-based phones. The diagram above shows the two firewalls supporting high availability between them, with two redundant ISP connections and a secondary Power over Ethernet (POE) switch to power the phones and provide any additional connectivity needed at the law firm.

The firewalls must be properly sized for the law firm’s traffic to the cloud, and properly configured to support the internal wireless access points. Overall, this is a fairly simple and straightforward design for our new, secure cloud network.

Selecting a cloud-based phone provider

For organizations running all or most of their workloads in the cloud, a cloud-based phone system –or Voice over IP (VoIP) provider — might also make sense. With so many VoIP providers available, the most important step in selecting one is simple: research. Decide what features are most useful (do you really need that online remote fax service?) and understand the pricing structure from each provider.  There are at least several dozen providers to choose from, so here’s a breakdown of some of the most useful features and options to look for:


Clearly there are many features to wade through. Most service providers offer almost all of the same features with only minor differences, and there are plenty of web resources to assist in refining the search. Remember that a cloud-based service still requires a local VoIP phone and POE switch in the office to support communications.

What else should be considered?

Understanding the technical options and specs of a cloud migration is clearly important, but there are a number of other considerations firms must take into account:

  1. Understand how your employees operate, including the workloads and applications utilized on a regular basis. It’s easy to be wooed by a service provider’s catalog of flashy features, but in many cases these capabilities are “nice to haves” that end up not being needed or utilized. Focus on the practical applications that will help your employees fulfill their daily responsibilities, and make sure the applications and infrastructure are easy to use and navigate.
  2. Don’t forget to train employees how to use your new cloud applications. Education should be ongoing; new hires will need to be introduced to the tools, as learning by osmosis works. And never mandate use of the applications, as this can lead to low adoption.
  3. Revisit how the applications are being used. Look for unused features that might improve productivity or solve chronic issues.

Ultimately, migrating workloads to the cloud should simplify the business, not complicate it. And a resilient and robust network is crucial to ensure business as usual.

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