Enterprises are often inaccurate when estimating how their businesses will grow and anticipating how their network and other infrastructure will need to grow to support it. Scalability is a challenge for network professionals managing software-defined wide area networking, and it can be particularly difficult the broader the geographical dispersion of the enterprise.

While the common response to enterprise growth is simply to add more appliances to expand SD-WAN capabilities, it’s not so simple.

Appliance capacity is a significant challenge. While SD-WAN functions through overlay tunnels that allow traffic to move between sites, appliances have a maximum number of tunnels they can handle. Further, as you connect locations and devices within a configuration that’s fully meshed, they quickly consume a lot of memory and resources housed in the appliance. The result is a demand for larger appliances or more appliances – both requiring additional spending.

Tunnel complexity is also a problem. The more tunnels an SD-WAN supports, the longer the recovery from any given outage. If the SD-WAN device experiences downtime, the tunnels must be re-established before connectivity is back, which may take several minutes in a setting where there are hundreds of tunnels on a single appliance.

SD-WAN controllers also have limits in the number of sites they can support. If a controller normally bears 100 or 200 sites, the growth of SD-WAN will require more controllers, which have to be networked together. This results in a complex network configuration.

Geographic reach is yet another difficulty, in that as sites are added, the local internet is unpredictable for use across a global network.

Still more challenges to SD-WAN scalability include optimization, security, and the support of mobile technology, which all need to be able to scale with a growing network. For instance, security may require its own enterprise-level appliance, which can then eat up more processing power. Enterprises are forced to choose between limiting which traffic gets inspected or upgrading the appliance supporting SD-WAN. Most enterprises choose to upgrade.

Cloud-Based SD-WAN

SD-WAN access through the cloud offers an answer to each of these challenges. With built-in security features and WAN optimization, a cloud-based solution takes many of the difficulties of scaling SD-WAN completely off the table.

Connecting a new branch location to the SD-WAN is a zero-touch configuration process, and appliances are capable of utilizing a single tunnel – removing the issue of tunnel capacity. Look for an SD-WAN solution that is supported by a global private backbone – eliminating security and performance concerns related to using the public internet.

Scalability is one of the key features of cloud-based SD-WAN. To learn more about this benefit as well as others associated with cloud networking contact us at Clarksys.