Software Defined Revolution: A look at SD-WAN offerings to DCI/Cloud Applications

A?wide area network (WAN)?is a network that connects?local area network (LAN)?across long distances. Large organizations often use a WAN to connect their various branch offices and locations to the central corporate network. In traditional WANs, the software that defines how traffic flows in the network is tightly integrated with the hardware that actually directs the traffic. Typically, this software/hardware combination is purchased from a single networking vendor.

SD-WANs are one of the biggest trends in enterprise networking today, even more so when combined with current interest in SASE (Secure Access Service Edge) architectures. Companies of all sizes are looking toward this next generation WAN technology as the best alternative to legacy networks to connect far-flung offices to resources hosted in the data center and the cloud. Many analysts and research firms expect the market to reach into the billions over the next couple of years.

What exactly is an SD-WAN? What is all the fuss about? How does SD-WAN work? And the obvious question about how does SD-WAN help keep network secure? Is it the same old hardware wrapped in new packaging or is it something worth investing our time and money in? Let’s find out.

Vendors from all walks are wading in: Start-ups, telcos, and edge-router providers are each offering a different take on the basic idea. Understanding the core differences is key. Whether a mid-sized business or a global enterprise, the following information should help to understand what SD-WAN does and which is right.

Section 1: What is SD-WAN? — Definition

SD-WAN is a virtual WAN architecture that provides multi-branch organizations with the ability to improve efficiency and reduce operating expenses. The areas needing improvement are generally associated with proprietary backhaul connectivity services, poor network performance, and inconsistent security posture and policy management. All of which inhibit low risk adoption of cloud-based applications and other digital transformation initiatives.

Brief of SD-WAN

Traditional WAN architecture increases latency and slows down network performance to cloud services. This has driven Software-defined WAN (SD-WAN) solutions to become increasingly popular as organizations request fast, scalable, and flexible connectivity among different network environments. They also seek to lower the overall total cost of ownership (TCO) while delivering enhanced application performance. But a subpar SD-WAN approach can significantly inhibit an organization’s ability to quickly adapt to changing business demands, especially if it does not offer integrated security.

Motivation behind SD-WAN innovation

Section 2: Why SD-WAN?

SD-WAN can handle a variety of connections and dynamically move traffic over the best transport available, and can provide both redundancy and much more capacity using lower-cost links. SD-WAN solutions are significantly cheaper than MPLS overall when time-to-installation and time-to-delivery are also considered. The best SD-WAN solutions offer zero-touch provisioning, allowing sites to be brought on quickly and not requiring networking or security experts to be on-site for installation.

Section 3: How SD-WAN works?

Like a police officer directing traffic – guiding the cars, semis, RVs, taxi cabs and more through intersections toward their final destinations – SD WAN dynamically manages the flow of data and determines the priority level of applications. Mission-critical applications, such as operating systems data, are directed over the traditional wide-area-network (e.g., MPLS). Lower-priority applications, such as email, get routed to the internet (e.g., broadband). This ensures that performance isn’t affected along the mission-critical pipeline, but keeps data flowing for all users.

SD WAN is a form of software-defined networking (SDN), which utilizes virtualization technology. Because of this, SD WAN can help alleviate much of the network management burden placed on IT resources, so they can focus on other high-priority tasks.

SD-WAN working algorithm

SD-WAN solution with live demo

Traditional WANs based on conventional routers were never designed for the cloud. They typically require backhauling all traffic – including cloud- destined traffic – from branch offices to a hub or headquarters data center where advanced security inspection services can be applied. The delay caused by backhaul impairs application performance resulting in a poor user experience and lost productivity.?Unlike the traditional router-centric WAN architecture, the SD-WAN model is designed to fully support applications hosted in on-premise data centers, public or private clouds and SaaS services such as Salesforce.com, Workday, Office 365 and Dropbox, while delivering the highest levels of application performance.

Section 4: SD-WAN Architecture

SD-WAN uses an abstracted architecture for its network. In an abstracted architecture, the network is divided into two parts: the control plane and the forwarding plane. The?SD-WAN architecture?moves the control plane to a centralized location like an organization’s headquarters. That way, the network can be managed remotely without the need for an on-premises IT crew.

SD-WAN architecture?with MPLS integration. Source:?MEF

• The SD-WAN?edge?is where the network endpoints reside. This can be a branch office, a remote?data center, or cloud platform.
• An SD-WAN Orchestrator?is the virtualized manager for network, overseeing traffic and applying policy and protocol set by CSPs.
• The SD-WAN Controller?centralizes management, and enables CSPs to see the network through a single pane of glass, and set policy for the orchestrator to execute. These components make up the basic structure of an SD-WAN. In addition, there are three main types of architecture: on-premises, cloud-enabled, and cloud-enabled with a backbone.
• An On-premises SD-WAN?is where the SD-WAN hardware resides on-site. CSPs can directly access and manage the network and the hardware it resides on, and it does not use?the cloud?for its connections. This makes it ideal for sensitive information that cannot be sent over the internet.
• Cloud-enabled SD-WANs?connect to a virtual cloud gateway over the internet, which makes the network more accessible, and provides better integration and performance with?cloud native?applications.
• Cloud-Enabled with Backbone SD-WANs?give?organizations?an extra backup by connecting the network with a nearby point of presence (PoP), such as within a data center. It allows traffic to switch from the public internet to a private connection. Moving to a private connection leads to a more?secure SD-WAN?and adds consistency in case the connection is overwhelmed or fails.

Section 5: SD-WAN Deployment

There are many companies who manufacture SD-WAN products, and every product has a different installation guide.

Switching to SD-WAN networking can completely revolutionize business by upgrading security, productivity, and collaboration opportunities while simultaneously reducing the costs. However, anyone looking to deploy SD-WAN systems in their business must accept that the choice of vendor is vital.

SD-WAN architecture is offered by a host of different vendors, but not all are worthwhile investments. After all, any SD-WAN system needs to be secure and reliable at all times while additionally offering value for money.

Section 5.1: SD-WAN Deployment Steps

When a company decides to migrate its traditional WAN architecture to Software-Defined WAN, the thing that always comes first is to deploy the controllers. The next step is to migrate the main data centers and hub?sites and lastly the remote sites such as campuses and branches.?

The main idea for doing it in this sequence is to have the hub sites route the traffic between the SD-WAN and non-SD-WAN sites for the period of the migration. Of course, if it is a brand new ground-up deployment, the sequence does not matter that much.

Section 5.2: Controllers Deployment Options

One of the main advantages of the Software-Defined WAN is that the controllers can be deployed in the public cloud.?This can significantly reduce the CAPEX/OPEX costs and improve the overall availability and redundancy of the management plane/control plane. Compare this model to the scenario in which have all controllers deployed on-premises. CSP need to accommodate rack space, power, cooling, physical servers, hypervisor, and virtual machines or containers. CSP have to manage redundancy and backups on their own. Using the cloud options, the management/control plane can be used as IaaS (Infrastructure-as-a-Service) or even?SaaS (Software-as-a-Service).

The following?options to customers to choose from:

• Cisco Hosted cloud?- The existing deployments shows that most customers (above 90%) opt for this approach. This is also the vendor's recommended model because Cisco takes care of provisioning all controllers, they handle the backup?and disaster recovery.?The customer is basically consuming the SD-WAN control plane as a Software-as-a-Service (SaaS) by using the vManage to create custom configuration templates for their device and administer the overlay fabric.
• Public cloud?- The customer could decide to host the controllers in the public clouds such as Azure and AWS. In this scenario, the controllers could be managed by a service provider or by the customer.?
• On-premises?- Of course, the controllers can be deployed in the company's data centers or private clouds. In this scenario, the customer is responsible for backups and disaster recoveries. This is usually the case with financial and government institutions that must be compliant with regional regulators.

Section 5.2: Types Of SD-WAN Deployment Models

There are three basic types of SD-WAN deployments: Internet-based SD-WANs, Telco and MSP Managed Service SD-WANs, and SD-WAN as-a-Service.?The performance needs?of CSP’s global users and applications, the skillset of their in-house team, and CSP’s appetite for taking on the job of building and managing an SD-WAN, will determine which deployment option is best for CSP’s business.

Section 5.3: Top 7 Considerations When Choosing an SD-WAN Vendor and Platform

Section 6: Benefits of SD-WAN

As a software-based solution, SD-WAN allows to manage entire network from a central portal, giving a “single pane of glass” view into current activity and performance. This makes it easier to manage, deploy and prioritize applications, optimize performance and prevent compromises across the network—a lot easier than with a traditional WAN like MPLS. In fact, it’s so easy, can make WAN-wide changes without calling in a specialized technician.?At the heart of it then, SD-WAN gives the total visibility and control. Simple.

Key benefits of SD-WAN

Section 7: SD-WAN with underlay and overlay Transport Fabric

SD-WAN supports a wide range of transport and internet access types. For example, with SD-WAN as CSP’s network overlay, CSP have flexible options for their network underlay, including:

• Broadband, like cable and digital subscriber line (DSL)
• MPLS for enterprises
• Fiber-optic
• Wireless
• Ethernet

Section 7.1: How does SD-WAN compare to traditional WAN?

Traditional WANs like multi-protocol labeling switching (MPLS) consist of connected routers spread across a geographic area. They involve extensive amounts of hardware, making it expensive and complicated to set up and maintain—and slow and cumbersome to optimize and scale.?

For example, an IT expert has to manually program each router at each location with a set of rules, or commands, on how to handle traffic throughout the network. So every time CSP want to make a change, they’ll have to plan and schedule, dedicating time and resources, which makes it difficult to pivot quickly.

In contrast, SD-WAN builds on the concepts of WAN and SDN to create a cost-effective, scalable connectivity solution. Along with its minimal hardware requirements—and the reduced capital expense and simplified implementation—SD-WAN centralizes network visibility and control, making it easier to optimize performance and defend CSP’s data. And with managed SD-WAN, it’s even simpler, with one expert partner helping CSP monitor and manage their network.

Section 7.2: SD-WAN vs. MPLS- Which is Better?

There are a handful of factors to consider before shifting an organization to an SD-WAN solution from a traditional MPLS configuration. So what is SD-WAN vs. MPLS useful for??The table below compares each option:

SD-WAN Vs MPLS

Section 9: Future of SD-WAN-Where is next?

Section 9.1: Automation Is the Future

As IT teams continue to struggle with rapid digital adoption and exponentially more data, SD-WAN solutions with integrated?Artificial Intelligence (AI) for IT Operations?(AIOps) have emerged as the key to automating manual tasks. AIOps can help IT teams with anomaly detection, event correlation and root cause analysis, allowing administrators to easily pinpoint issues and speed up response times for problem remediation. SD-WAN solutions with integrated AIOps capabilities will help organizations continuously scale and simplify operations.

Section 9.2: Next-Generation SD-WAN

Legacy SD-WAN solutions struggle with the shift to cloud adoption and high-performance bandwidth. There is a growing need for a next-generation SD-WAN solution that delivers essential branch services – such as networking, security and more – from the cloud.

Next gen SD-WAN

A next-gen SD-WAN solution should be:

• App-defined
• Autonomous
• Cloud-delivered

Section 10: Vendor Innovations

Collaboration of Cisco and Microsoft for SaaS application

Cisco's SD-WAN's telemetry analysis and monitoring(SD-WAN with thousand eyes)

NTT's SD-WAN solution

Conclusion

SD-WAN's intelligent software can be seamlessly integrated alongside CSP’s current WAN or used to augment CSP’s MPLS network – or can replace CSP’s MPLS altogether. Upon deployment, CSP’s SD-WAN will recognize and route applications and traffic through the public internet or CSP’s private network according to protocols, policies and app-specific SLAs that CSP’s company defines and manages through a single pane of glass. This allows CSPs to monitor network health and application performance in real time. Until now, enterprises had to choose between expensive, complex, private or MPLS networks or lower cost, but less reliable broadband WAN connections. SD-WAN disrupts these aging technologies and renders MPLS networks obsolete.

By establishing a unified network plane across disparate networks and providing a centrally managed platform for network management, SD-WAN simplifies CSP’s WAN management through a single cloud-based portal, allowing CSP to deliver unprecedented control over agility, performance, bandwidth and security.

Thank you!!

Monowar Hossain

Microwave Unit Head (Planning and Operation)

VEON, Bangladesh

Email: [email protected]

Mob: +8801962424691