Today’s application and network architectures require a new approach, with the emergence of cloud, virtualization, and as-a-service models upending traditional enterprise networks. In this cloudy world, organizations are being forced to rethink how they design wans to connect and unify scattered sites.

Management trends and practices are changing, and network operations teams are under increasing pressure to simplify networks, make them more flexible, centrally controlled, and optimize application performance.

Modern WAns must support connectivity between traditional applications and delay-sensitive real-time services such as voice over IP (VoIP) and video conferencing.

This article will take a scientific look at networking challenges and opportunities in WAN (wide area Network) — where it started, how it evolved, and why SD-WAN offers those opportunities for the future.

1. The router

Traditionally, routers typically provide WAN connectivity at the enterprise (home) edge, and these routers lack the policy-based control and automation and intelligence of cloud connectivity. Routers generally don’t care about the details of the underlying transport infrastructure; This lack of abstraction limits their flexibility in connecting to the cloud.

2. Dedicated links, MPLS, and VPN

MPLS and dedicated line services are dedicated connections provided by service providers. These services provide predictable performance with guaranteed traffic performance and delivered SLAs. Unfortunately, they tend to be much more expensive than broadband Internet services, which have the advantage of being easier to obtain and deploy than MPLS and private line services.

While MPLS provides key benefits including scalability, performance, increased bandwidth utilization, and reduced network congestion, it is not designed for the cloud and SaaS. This is mainly because all traffic must be sent back/hairpins, adding latency that ultimately affects the user experience.

VPN links provide an economical and secure alternative to remote connections. For security, these connections establish an encrypted tunnel over the public Internet that connects remote users to the corporate network via a VPN client. While VPNS continue to be widely used, the technology still faces bandwidth, scalability, and security challenges.

Typical VPN connection from branch site to data center site

3. Wan optimization

MPLS costs and application-specific requirements (e.g., latency sensitivity) are early drivers of WAN optimization over international links. With the rise of real-time voice and video communications, services are highly sensitive to latency and jitter, a welcome feature.

WAN optimizations include basic inline compression and a range of TCP optimizations, data deduplication, application proxies, and protocol-specific optimizations. These features have proven effective in managing delay-sensitive applications and transferring large amounts of data over a WAN, especially for global transports.

Deploying a WAN optimization solution is complex and requires physical devices at each end of the connection. These systems are limited to application proxy support and encryption applications, such as TLS and SSL-based solutions. Wan optimization equipment will not improve the user experience outside of the traditional office environment.

The superheroes of today’s networks of networking, SD-WAN, and software-defined wide area networks have arrived

4. SD-WAN

If someone asks how to define sD-WAN or the difference between WAN and SD-WAN?

The answer is that SD-WAN is about application performance and quality of experience for the end user.

Over time, applications become smarter and less frequent over wan links. Services are moving to the cloud (e.g., SaaS), and the public Internet is becoming more affordable and available. In addition, SD-WAN makes broadband Internet connections more reliable, higher performance, and more secure for business communications and services; They are no longer seen as just the best connections. Being transport-independent, SD-WAN can focus on application performance, using application identification, bandwidth aggregation, and dynamic path selection while providing security and minimizing routing complexity. The following figure shows the architecture of a software-defined network:

Sd-wan allows enterprises to adopt software-defined Networking (SDN) practices that separate data, control and management planes.

Key indicators of SD-WAN include:

  • Transmission independence
  • Safety cover
  • Application performance
  • Simplicity, a single management portal for administration, configuration, and troubleshooting