Decoding SD-WAN - part1

Gartner predicts “half of WAN edge infrastructure refreshes will be based on SD-WAN by 2020”.

What exactly this statement means? One thing is very obvious that there is going to be a disruption in the edge routing market due to something called 'SD-WAN'. If this term sounds unfamiliar then this article might give you some idea.

Today, the Internet/broadband based connectivity is increasingly serving as the cheaper alternative for directly connecting branch offices to data centers or cloud-based services like public or private cloud. In fact in some cases some enterprises have replaced traditional MPLS-based networks with cheaper Broadband/LTE connections. This situation creates new opportunities as well as challenges with respect to applications performance and user experience. Where exactly SD-WAN fits in this picture?

Challenges with current WAN designs:

Managing WAN topologies with legacy design approaches to branch networking is becoming too costly and ineffective. Even small configuration changes are hard to get right and also too often compromise the availability, performance and/or security of the overall network. There is an ever growing demand for Bandwidth due to cloud-centric application approach. Also the lack of complete visibility into application behavior and performance creates further challenges. Direct Internet access at multiple remote sites bypasses data-center-grade security services, weakening the enterprise’s information-security policies. Encrypted apps might compromise end-to-end visibility. Limited MPLS capacity and no SLAs guarantee for broadband Internet yield unpredictable performance slowdowns that users will notice before the network admin does.

So what is SD-WAN & how it solves the problem?

To avoid existing WAN issues, enterprises are beginning to adopt SD-WAN, a network overlay based solution that brings policy, ease of deployment, added reliability and visibility to existing WAN connectivity. The transport may include anything from cable modem and DSL broadband services to MPLS to wireless links based on LTE or whatever.

SD-WAN has five major components: Transport independence, Application visibility & optimization, intelligent path control for application traffic, end-to-end security and SDN based orchestration. 

SD-WAN enables network architects and operators to take a holistic approach that hides the underlying complexity of traditional network deployments and makes branch & cloud connectivity irrespective of what transport media the enterprise is currently using. Instead of trying to manage thousands of manually configured routers at the branch locations, enterprise can centralize and simplify management using virtual network designs, zero-touch provisioning and business-aligned policy-based orchestration which all are part of a standard SD-WAN offerings from different vendors.

SD-WAN also can help businesses support the hybrid WAN, noting that enterprises want to seamlessly combine multiple kinds of links as a homogeneous whole, and maintain control so they are not locked into a particular service provider for accessing services. And it enables the use of virtual customer premise equipment, which tends to be more affordable and flexible than traditional edge gears.

As public and private cloud use continues to grow, WAN performance becomes critical to latency-sensitive and mission-critical workloads and inter-datacenter business continuity. As enterprises plan and implement comprehensive cloud strategies, WAN architectures need to be considered alongside and that’s where SD-WAN can play a critical role for the enterprise businesses.