An SD-WAN can operate as an overlay to the existing network, providing you tools to turn up new branches rapidly without impacting the stability or configuration of your infrastructure. Use whatever type of branch connectivity is available, deploy zero-touch SD-WAN branch configurations from a central orchestrator and steer the traffic over auto-established VPN tunnels to an SD-WAN gateway at your existing data center or cloud location.

Branch-to-branch communications are extremely difficult. Branches change, they come and go – each time impacting every other branch’s configuration. The traditional approach of backhauling every branch connection via a hub site, or the central data center location, creates untenable global delays.

An SD-WAN is an ideal solution. The basic branch-to-data-center or cloud location connectivity can remain unchanged. But branch-to-branch communication can be steered over the SD-WAN overlay where VPN tunnels are built as and when needed. It is as simple as indicating on the central orchestrator that security is required on these traffic patterns.

Large, mature networks have such a significant investment in existing infrastructure that upgrading, or configuring branch locations for access to a new cloud or SaaS application, is often an overwhelming undertaking. Rip-and-replace is technically the easiest solution, but almost never a viable financial choice.

By deploying zero-touch SD-WAN technology to the branch, access to the new application or traffic pattern can be steered via the SD-WAN overlay while existing applications and access remain undisturbed—using either the site’s existing transport link or a new link. Over time, additional applications or traffic types can be migrated to the SD-WAN network until the older equipment is decommissioned.

Large mature networks also have to deal with branch turnover: some branches must be brought down due to shifting business patterns; mergers and acquisitions demand that another whole network—perhaps a fairly large one—must be promptly bridged and integrated with yours; divestiture requires the opposite, segmenting and carving out, but not dismantling, and handing over cleanly and securely a network that is now independent from yours.

Overlay networks are enormously helpful with these challenges. During an acquisition, the old and new networks can be bridged via the SD-WAN overlay. Conversely, select branches on an SD-WAN can easily be moved to a new, separate SD-WAN. This can be done from the central multi-tenant orchestrator and requires no physical change to any location.