A lot has changed in how people work during the past twenty years. Co-working spaces, mobility, and the cloud now are common. Businesses are spread out and branch offices are empowered.
This new functionality is a good thing, of course. But, at the same time, it raises a big challenge: Multiprotocol Label Switching (MPLS), the way in which most branch offices network today, is a poor match for this new environment. It is an expensive and rigid one-size-fits-all approach to an environment that prizes fluidity and flexibility.
The answer is Software Defined-Wide Area Networking (SD-WAN). It matches the network to branch offices’ needs and provides a superior user experience. It also the potential to reduce costs.
Our Complete Guide to SD-WAN Technology article provides an in-depth coverage on SD-WAN Security, Management, Mobility, VPNs, Architecture and more.
SD-WAN is still a work in progress, no doubt, but the technology is positioned to be the next wave in branch office connectivity -- here's why.
Enterprises generally conﬁgure WANs in a classic hub-and-spoke manner. Branches are the ends of the spokes and resources are in the hub, typically the headquarters or datacenters. Internet trafﬁc is backhauled across the MPLS-based WAN to the hub for delivery through a secured, Internet access connection.
That’s a solid, bulletproof approach. However, branch operations have changed radically since MPLS was introduced in the early 1990s. Back then, branch offices were comfortable with a T1 or two. Today's offices need 5x that amount. Back then, most applications and services terminated at MPLS-attached datacenters, not the Internet. Today, most traffic goes out to the Internet. Back then most work was done in offices. Today, work is done, well, everywhere.
MPLS-based architectures are a poor fit for the new branch. Bandwidth is far more costly than Internet access (exact amounts will vary between regions and packages). Installation can take months, especially if the provider doesn’t have any available circuits; bandwidth upgrades weeks. This, needless to say, is too slow for today’s environment. International deployments only add to the problems.
The cost and inflexibility of MPLS leads many organizations to skimp on branch office bandwidth and, often, skip on redundancy. Instead, the sites instead are linked by non-redundant cable, DSL or wireless services and therefore are vulnerable to circuit failures and downtime. The use of separate networks makes creating a fully meshed architecture, where every office has a direct connection to every other office, far more difficult, impacting Active Directory and VoIP design. Those connected to MPLS face delays when more bandwidth is needed, such as for branch expansions and seasonal traffic spikes.
The same antiquated approach extends to contracts. Branch offices often are temporary. One may start in somebody’s home. That worker may quickly be grouped with other workers at a larger branch across town. The three-year contracts offered by MPLS providers is simply inappropriate for such small- or transient-branch offices.
And none of this says anything about two shifts in enterprise networking -- the cloud and mobility. Backhauling Internet traffic adds too much latency, disrupting with the user experience. Often traffic is backhauled only to be sent back across the Internet to a site near the edge. This back and forth -- aptly called the “trombone effect” -- causes significant latency problems and consumes expensive MPLS bandwidth, particularly when the central portal and branch office are far from each other.