How to implement SD-WAN: Key steps, best practices, and challenges
SD-WAN offers a plethora of benefits for businesses today, but implementation can seem complex if you’re not sure where to start.
Published at
3 September 2025
Imagine you’re running a growing business. Your team is spread across multiple locations, everyone needs fast and reliable access to apps, and your old network just isn’t keeping up. SD-WAN implementation promises speed, scalability, and flexible connectivity - exactly what you need to keep things moving.
But getting started can feel overwhelming. Where do you begin? Which solution is the right fit for your business? With the right approach, implementing SD-WAN doesn’t have to be complicated.
What is SD-WAN and why should you consider it?
Software-Defined Wide Area Networking (SD-WAN) is a modern networking approach that enhances the performance, security, and flexibility of enterprise networks. By leveraging software-defined technology, SD-WAN allows businesses to optimise traffic routing, improve application performance, and reduce costs in comparison with traditional WAN solutions.
To understand SD-WAN in more detail, check out our in-depth guide: What is SD-WAN?
Understanding SD-WAN implementation
Rolling out SD-WAN isn’t as simple as plugging in new hardware and calling it a day. It’s a bigger shift - a change in how your business thinks about connectivity, security, and application performance. That’s why diving in without a plan can be risky.
A smooth deployment starts with structure. Take stock of your current network, get clear on your top priorities, and make sure the right people and resources are in place. With those steps in hand, the transition becomes less of a leap and more of a guided journey.
Equally, your SD-WAN deployment strategy will hinge on your business requirements, whether that’s performance enhancements, security improvements, or greater cost efficiencies. Each strategy will have an impact on how your SD-WAN solution is designed, deployed, managed, and integrated with your existing infrastructure.
“With different types of SD-WAN architecture providing varying levels of control and integrations with on-premises and cloud applications, businesses need to fully understand their connectivity goals before choosing a solution. This also includes considering planned changes like business size, budgets, security needs, and regulatory compliance.”
At Nasstar, our teams have extensive experience in SD-WAN implementation. We know how it works and how your business can get the best out of it, so while it’s a good idea for you to have some understanding of how SD-WAN is implemented, we’re here to do the heavy lifting.
What is required for SD-WAN deployment?
Before deploying SD-WAN, businesses need to consider several key requirements:
SD-WAN vendor selection: Choose the right provider based on features, scalability, security, and cost.
Security and compliance: Ensure the solution meets data protection regulations and includes advanced security measures.
Integration with existing systems: Plan for compatibility with current networking equipment and cloud-based applications.
IT team readiness: Train personnel to manage and troubleshoot the SD-WAN environment.
6 key steps to implement SD-WAN successfully
A successful SD-WAN implementation should consider six key steps. Each step of your SD-WAN implementation journey is a vital consideration and should be handled carefully to ensure you get the most from your investment.
1. Assess your current network infrastructure
Before deploying SD-WAN, evaluating your existing network architecture is key. This will help you understand its limitations and identify areas for improvement. Key factors to consider include:
Current connectivity options: Are you using MPLS, broadband, LTE, or a combination?
Network performance challenges: Are there frequent outages, high latency, or bandwidth congestion?
Traffic patterns and application needs: Which applications require priority (e.g., VoIP, cloud apps, video conferencing)?
Security posture: What measures are in place to protect data and prevent cyber threats?
This assessment helps determine how SD-WAN can address specific pain points and improve overall network efficiency. You should also identify pain points in your current WAN setup and conduct a cost-benefit analysis of SD-WAN adoption to make an informed decision.
2. Define your business objectives
A successful SD-WAN deployment should align with your business goals so you can measure the success of your deployment effectively. Before you choose an SD-WAN solution, you need to clarify:
What problems SD-WAN needs to solve (e.g., reducing costs, improving cloud connectivity, enhancing security).
Which sites and users will be impacted (e.g., branch offices, remote workers, data centres).
What level of performance and security is required for critical applications.
3. Plan for integration with existing systems
SD-WAN doesn’t operate in isolation. It must integrate seamlessly with your current tech stack, or a new stack of your choosing if you’re embarking on a full digital transformation project. The last thing you want is to invest in an SD-WAN solution to find out it causes disruption with your other IT investments.
Consider integration with the following systems:
Existing WAN infrastructure (routers, firewalls, VPNs)
Once you've assessed your network and selected the right SD-WAN solution, the next step is to create a detailed deployment plan. A well-structured plan ensures that the transition to SD-WAN is smooth, minimises downtime, and aligns with business objectives.
As part of this, you’ll want to define your network policies, security configurations, and traffic prioritisation rules to ensure your operations are well supported from day one. Redundancy and failover mechanisms should also be put in place for high availability.
By incorporating these elements into the SD-WAN design, you can achieve a resilient, high-performance network that adapts to changing demands while maintaining security and uptime.
5. Establish a phased rollout strategy
Rather than deploying SD-WAN across the entire organisation at once, phased implementation is recommended.
Start with a pilot deployment at a few sites to test configurations and performance.
Gather feedback and adjust before expanding to more locations.
Ensure proper training for IT teams and end-users to maximise adoption and minimise resistance.
6. Optimise and monitor SD-WAN performance
Once SD-WAN is deployed, ongoing optimisation and monitoring are essential to ensure the network continues to perform at its best. SD-WAN solutions provide real-time visibility into network traffic, allowing IT teams to analyse usage patterns, detect congestion, and fine-tune routing policies.
By continuously optimising your traffic flow, you can ensure critical applications receive the bandwidth they need while minimising latency and downtime. Many modern SD-WAN solutions incorporate artificial intelligence (AI) and machine learning to automate network management. This can help you predict potential issues, automatically reroute traffic to avoid disruptions, and optimise network performance based on historical data.
Security is also a part of this step. Cyber threats are constantly evolving, and SD-WAN security must evolve alongside them. Regularly reviewing and updating security policies, such as access controls, encryption standards, and firewall configurations, keeps your network protected against new vulnerabilities.
Key benefits of SD-WAN for modern businesses
SD-WAN offers several benefits for businesses today, from cost efficiency to simplified network management. Depending on your business goals and what you aim to get out of your SD-WAN solution, these benefits could prove invaluable to your business.
Cost savings
SD-WAN optimises bandwidth usage by utilisting all available connections to lower overall network costs. More cost-effective next-generation fibre to the premises (FTTP) broadband, Low Earth Orbit, and LTE connections can be combined to reduce overall costs yet provide connection media resiliency.
Enhanced network performance
Intelligent traffic routing ensures critical applications receive priority, while reducing latency and packet loss for cloud-based services and VoIP. Features such as dynamic path selection, application-aware traffic steering and automatic failover enhance the network performance for users and applications:
Dynamic Path Selection (DPS)
SD-WAN continuously measures network performance metrics like latency, jitter, and packet loss across all WAN links. This enables real-time traffic steering to the best-performing path and prevents performance degradation for critical applications such as VoIP, video conferencing, or SaaS.
Application-Aware Traffic Steering
SD-WAN can identify applications even when traffic is encrypted, allowing it to prioritise bandwidth for high-performance demands such as Microsoft 365, Zoom, or Teams. This intelligent routing ensures essential applications receive optimal network resources while lower-priority traffic is directed over less optimal links.
High Availability & Seamless Failover
SD-WAN instantly reroutes traffic to a secondary link if the primary one fails or does not meet SLA thresholds. This maintains session persistence for ongoing applications, so users don’t experience interruptions.
Simplified network management
SD-WAN centralised network management platforms can provide centralised insights - a single pane of glass - for customers to view important security and device information with intuitive dashboards, charts, and tables. Centralised control enables easy configuration, monitoring, and troubleshooting, which also reduces IT workload by automating network tasks.
This allows users to get a real-time and historical picture of their network traffic and security posture, and assists with comprehensive analysis and investigation of applications, devices, policies, and network resources.
“Nasstar’s SD-WAN Portal provides customers with access to a web portal/dashboard to view live and historical SD-WAN network and application performance data. This allows them to see security events logged from the Managed SD-WAN and SD-Branch appliances including SD-WAN routers and firewalls, SD-Branch Switches, and Wireless APs.”
Improved security
SD-WAN has security best practices in mind. Integrated security features like encryption, firewalls, and segmentation protect data, ensuring compliance with industry regulations and standards.
Secure SD-WAN Services provide security analytics and reporting features, allowing customer to:
View real-time and historical SD-WAN traffic logs
Access and download secure SD-WAN reports
Review compliance reports to ensure they meet industry regulatory requirements
Greater flexibility and scalability
SD-WAN adapts to business growth and changing network demands, supporting hybrid and multi-cloud environments seamlessly.
SD-WAN is transport-agnostic, enabling the use of multiple connection types simultaneously, including:
MPLS
Broadband
LTE/5G
Satellite
This provides greater flexibility for organisations, particularly for site use cases.
Cloud-based orchestration provides central management, making it easy to scale from a few sites to hundreds or thousands without the need for hardware upgrades at a central data centre.
SD-WAN also supports elastic bandwidth use by aggregating multiple links and dynamically adjusting usage according to traffic demands, thus eliminating costly bandwidth overprovisioning.
Integrating new cloud services or remote users through ZTNA and CASB on the journey towards SASE becomes more straightforward too. SD-WAN extends security and policy enforcement beyond branch offices to end users, public cloud, and SaaS, streamlining the process of connecting distributed environments and providing the foundation for the adoption of a SASE type architecture.
Co-Managed Collaboration
Nasstar’s SD-WAN Co-Managed Service provides a flexible, collaborative managed networking service that combines the strategic goals and needs of customers’ network/IT teams with the advanced expertise, 24/7 monitoring, and lifecycle support of Nasstar’s managed service.
This allows customers to make day-to-day network operational changes, whilst ensuring business continuity that enhances network performance and end-user experience. By leveraging centralised management and orchestration tools, and real-time analytics, there is joint accountability between the customer and Nasstar.
Common challenges in SD-WAN implementation and how to overcome them
Like any connectivity solution, SD-WAN deployment challenges are not uncommon. Thankfully, there are processes you can put in place to mitigate any challenges you may face during the implementation process.
Deployment complexity
Challenge: Integrating SD-WAN with existing network infrastructure is complex.
Solution: Conduct a thorough assessment and work with experienced vendors for a smooth transition.
Assess your current network infrastructure by evaluating existing connectivity and identifying performance challenges such as outages or latency. From here, you can understand application needs and security measures to highlight pain points and determine success criteria.
Next, clarify your business objectives by determining the problems SD-WAN should address. This could be anything from improving cloud connectivity to enhancing security. Then you can identify which users and sites will be impacted, along with the required performance and security levels for critical applications.
Choosing a partner with experience in SD-WAN vendors and technology, alongside a track record of delivering intricate connectivity solutions to end customers is key to a successful SD-WAN deployment.
Security concerns
Challenge: SD-WAN introduces new security risks if not properly configured.
Solution: Choose an SD-WAN solution with built-in security features and enforce strong policies.
A secure SD-WAN solution with integrated firewalls and security services is vital for edge sites with internet connectivity, and this is why:
Centralises security
Defends against sophisticated threats
Secures internet access
Limits unauthorised access
Offers visibility into cloud app usage
A unified approach to security, including Zero Trust Network Access (ZTNA), CASB, and a path to Secure Access Service Edge (SASE) are considerations for any customer embarking on an SD-WAN project.
Connectivity issues
Challenge: Network performance can vary depending on ISP connections.
Solution: Use multiple ISPs for redundancy and a Managed Service that reports and provides recommendations for improvement.
The SD-WAN solution should be deployed with high availability and resiliency at key sites with multiple redundancy mechanisms using various WAN links, including Ethernet, broadband, and cellular. This avoids single points of failure and automatically reroutes traffic if one connection drops. Link aggregation in active/active or active/passive setups boosts bandwidth and provides seamless failover for critical applications.
Features such as stateful failover ensure active sessions, including VPN tunnels, remain uninterrupted during a failover event, minimising connection drops and service disruptions for users. Additionally, application-aware failover prioritises critical business applications, ensuring minimal downtime and maintaining seamless performance when connectivity issues occur.
Managed Services that continuously optimise network and application performance is key. This is especially important when overcoming connectivity issues that may be caused by bandwidth saturation, spikes, multi-cloud expansions, or new real-time application rollouts.
Lack of internal expertise
Challenge: IT teams may struggle with SD-WAN management.
Solution: Work with a partner who can support full or co-management for a managed SD-WAN service.
A co-managed service offers a flexible managed networking solution that integrates customers' network/IT objectives with expertise, monitoring, and support.
At Nasstar, customers can manage day-to-day network operations while benefitting from centralised management tools, real-time analytics, and shared accountability with our Network Service teams to ensure business continuity and improved performance.
Our Co-Managed SD-WAN Service offers tailored administration access to the SD-WAN infrastructure based on expertise, balancing flexibility and risk. Network or IT admins can self-manage changes to SD-WAN components, including SD-Branch Switches and Wireless Access Points, through a central management platform.
For improved security, access is governed by role-based access control (RBAC), with all users receiving at least read-only rights, and selected users granted higher administrative privileges based on their skills.
Best practices for optimising your SD-WAN deployment
Following our six key steps for SD-WAN implementation is key to getting the most out of your investment and deployment, with best practice in mind.
At Nasstar, we can help you with your implementation from start to finish. Our key takeaways for optimising your SD-WAN deployment are:
Define clear network policies
Monitor network performance continuously
Implement redundancy and failover strategies
Keep security front of mind
Plan for future scalability
Implementing SD-WAN can significantly enhance network performance, security, and cost efficiency. By following our key steps, addressing challenges proactively, and adopting best practices, you can achieve a seamless SD-WAN deployment.
Nasstar takes a best-practice, least-risk approach to SD-WAN implementation. Our process ensures alignment with strategic goals such as cloud adoption, cost efficiency, and improved application performance. From there, a phased rollout is carefully managed to minimise disruption, validate performance, and maintain consistent connectivity.
Key steps include:
Review existing infrastructure and business needs to align the SD-WAN strategy with long-term goals.
Establish a secure link between existing and new WAN environments before rollout.
Deploy to selected sites first to test performance, security, and manageability.
Roll out gradually across sites with continuous monitoring and validation.
Use zero-touch provisioning and centralised templates to accelerate deployment and ensure consistency.
Provide visibility, testing, and assurance at each stage to keep stakeholders informed and engaged.
02
The implementation timeline for SD-WAN varies depending on the size and complexity of your network, but it always follows a phased approach.
Nasstar begins with technical workshops to define the delivery plan and capture detailed design requirements. A pilot deployment is then carried out at selected sites to validate performance and ensure expectations are met before moving into full rollout. The overall duration depends on the number of locations, the complexity of existing systems, and the preferred pace of rollout.
03
The cost of SD-WAN implementation depends on a variety of factors, from bandwidth requirements and number of sites to the deployment model and chosen features. Costs can range widely depending on whether lower-cost broadband services (such as SoGEA or FTTP) are used, or higher-cost fibre-based Ethernet connections. Additional resilience, such as multiple fixed-line services or 4G/5G mobile backup at key sites, can also increase overall spend.
Ultimately, each SD-WAN deployment is tailored to your organisation’s needs. Nasstar works with customers to align the solution to business priorities, balancing cost, risk, and performance.
04
Yes. SD-WAN is designed to work alongside existing infrastructure, making it an upgrade rather than a disruptive replacement. It can overlay traditional MPLS, point-to-point, or internet-based connectivity using encrypted tunnels and dynamic routing, allowing you to maintain legacy connections while gradually shifting to more cost-effective links - all centrally managed.
