About SD-WAN

Reference 1: Definition of SD-WAN by Gartner
Easy replacement of WAN router
Traffic control at application level (between multiple WANs)
Easy construction and operation of hybrid WAN etc.
Additional services such as NFV can be used easily and safely
Reference 2: Pros and cons of SD-WAN by Gartner
Pros
Easy operation management
Efficient use of various WANs
Traffic visibility and security improvements
low cost
Cons
Technology and products are immature
The line quality itself is not improved.
Usage scene is limited
More unique than traditional solutions
Management is complicated by using multiple WANs
Source: Gartner, Inc. “Technology Overview for SD-WAN”-02 July 2015

Basic mechanism of SD-WAN
In general, companies are building WANs using dedicated lines, broadband lines, mobile lines such as LTE / 3G.
SD-WAN uses the above-mentioned physical line as an underlay line, and realizes a virtual WAN configuration with overlay without depending on the line type.

This eliminates the so-called “carrier binding” and allows you to freely select the main line and backup line from a variety of physical lines such as multi-carrier lines and mobiles to configure a corporate WAN.
In addition, the same virtual overlay network can be centrally managed regardless of domestic or overseas, so the load on WAN operation / management can be reduced.

Why is SD-WAN now?
An era in which business needs speed. The network is also required to have a flexible configuration that can respond to changing circumstances and the rapid addition of bases associated with business expansion and M & A.

The ICT environment surrounding the network is also changing. The traffic volume has increased dramatically due to the expansion of SaaS and private cloud use represented by Office365. Remote work (using mobile) in business has also increased dramatically due to work style reform. Security measures at internal and external boundaries have reached their limits, and the role of the network itself is changing.

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