Hi, I'm Derek Granath, Vice President of Product
Marketing for silver peak systems. Welcome to our multi-segment SD-WAN video series. This series of short videos is intended to
provide you with everything you need to know about SD-WAN but were afraid to ask. In this segment, we'll define what is an SD-WAN Let me start by redefining the job of the
WAN The job of the WAN is to connect users to
their applications, anytime, from anywhere and to wherever the applications reside But Let's start by looking at the way we've
built WANs for the past two-plus decades. Branch offices - where more than 80% of business
transactions are handled - were connected to a headquarters'-based data center by a
router over a leased line connection - usually MPLS. And that model was fine back then because
all applications were hosted in Enterprise data centers. Traffic was "routed" from source to destination
based on TCP addresses, access control list tables and complex routing protocols All of the control functions were distributed
across all of the routers But traffic patterns have changed with the
introduction of applications moving to the cloud - this could be enterprise apps that
are now hosted in Amazon Web Services or Microsoft Azure or Google Cloud or Software-as-a-Service
apps like SalesForce dot com, WorkDay, Office365, Box, Dropbox, FaceBook and more. Sending cloud traffic that is destined for
the internet back to headquarters simply doesn't make sense. It adds a delay that degrades application
performance and it consumes costly leased line bandwidth. Why not use the internet to reach apps that
are hosted in the internet! This has driven the need for a more intelligent
software-driven - or Software-Defined model for the WAN - an SD-WAN. Instead of routing traffic just based on addresses,
an SD-WAN is application aware. It uses software to more intelligently route
or steer traffic across the WAN based on the business requirements for an application. These include the priority of the application,
the performance required and the security policies that must be enforced An SD-WAN that has the right set of features
also enables the ability to actively use the internet as a secure, reliable form of WAN
transport. And even 4G/LTE in addition to broadband internet
and MPLS services. The SD-WAN de-couples the WAN transport services
- sometimes called the data forwarding plane - from the applications and from the control
function. This is a very different model than the traditional
router model where this was all combined in every device. Also, with an SD-WAN, this control function
- referred to as the Control Plane - is centralized. The Quality of Service and Security policies
that dictate how an application should be delivered to the user are defined centrally
and "programmed" AUTOMATICALLY to 100s or even 1000s of SD-WAN appliances at the branch
locations. This leads to more consistent, predictable
application performance as well as consistent and improved security across the WAN. And with a software model, adding locations,
adding applications, changing policies and more is much easier than with the old router-centric
model. In summary, an SD-WAN is a more intelligent,
cloud-first way to build a WAN that improves business productivity, end-user quality of
experience, accelerates business initiatives and has the potential to lower costs.
