The adoption and deployment of software defined WANs (SD-WANs) continues to skyrocket. ZK Research predicts the technology will grow at almost 70 percent CAGR between now and 2022. For most businesses, the WAN is long overdue for an upgrade as conventional router-centric WAN architectures have been in place for well over three decades now. If done right, deploying an SD-WAN can be one of the rare IT initiatives that can lower costs, improve worker productivity and simplify IT operations.
The key point in what I said was “if done right” and this can vary quite a bit from company to company. One of the biggest debates in SD-WANs is the use of private network links versus broadband which uses the public Internet. For small businesses, this is a no-brainer as their business needs can be addressed using any flavor of broadband including cable, Ethernet, DSL or even cellular. With small businesses, traffic volumes are low and the distance the packets have to travel are relatively short so the overall quality of experience, even for bandwidth hungry applications, is likely to remain high.
For large, distributed organizations, the story can be quite different. The relatively low price point of public broadband makes it quite appealing, but there are some inherent risks associated with using the public Internet as the backbone of a global organization. The first, and most obvious risk is quality, particularly for real time and bandwidth intensive applications. Users are not likely to notice if the experience of e-mail is impacted, but they will immediately if a voice call is dropped or if video sessions are choppy as the conversations become unintelligible.
In many ways broadband is the wild west of network services and many other technical challenges are involved in deploying applications over public Internet connections. Below are the top concerns that network professionals should be aware of:
- Variable circuit sizes. Broadband speeds can vary widely from under 1 MB to multi-gigabit. There is also variability in the type of broadband where fiber speeds greatly exceed any kind of conventional copper connectivity. Wireless services appear attractive, but often have high latency and are metered services. Also, with most broadband services, the network upload and download speeds can be different.
- Inconsistent bandwidth speeds. Some broadband types, like cable and cellular services, are shared networks. This means if a business happens to be one of only a few entities connected in that area, the speed will likely be great, often exceeding the subscribed rate. However, if the area is oversubscribed, the speed can be significantly lower that what is expected. Adding to the complexity is that time of day can play a role as well as in highly dense areas, consumer usage can impact business users during peak periods.
- Network specific issues. Various broadband types have different characteristics, which can cause application issues. For example, 4G services can suffer high packet loss, where Ethernet can often drop packets.
Another challenge with broadband, particularly for large organizations is managing the number of broadband providers. There is no single, global broadband provider. In fact, there are very few large regional ones. In the US alone, there are currently almost 900 broadband service providers. A global organization would need to manage dozens or even hundreds of relationships and contracts and then understand how terms can vary from region to region.
Legacy, private networks, such as MPLS have the luxury of being very consistent from location to location. Also, the ability to use class of service for proper application categorization ensures optimal application performance. However, MPLS can be very expensive and is why many businesses initially evaluated SD-WAN.
So, what’s the choice for large enterprises? Stick with what they have or live in a world of increasing complexity? There is a third option and that’s to use a managed service provider (MSP) for turnkey managed SD-WAN services. Think of an MSP as being a management overlay that can mask much of the complexity for the customer. An SD-WAN can be transformative and provide tremendous value for distributed businesses, but they do require some work to get going and most MSPs can bring a wealth of valuable best practices. Also, although most people consider SD-WAN to be about greater efficiencies in transport, there are other things to consider, such as the use of WAN optimization, security capabilities, QoS settings, etc. Often the tuning and tweaking portion of a deployment can go on for months. An MSP can greatly shorten this time and may offer tiered value-added services on top of a managed SD-WAN service.
For large enterprises, building an SD-WAN can be very appealing, but managing the complexity of potentially dozens of service provider relationships and contracts can be daunting. Turnkey managed SD-WAN services can be a great way to realize all of the benefits of SD-WAN without the associated risks.