Meraki SD-WAN application-level path selection

Meraki SD-WAN Application-Level Path Selection is one of the powerful features provided by Meraki’s SD-WAN solution. It allows you to intelligently route traffic based on the specific application type or category, enabling optimized network performance and ensuring that critical business applications receive the appropriate network resources. This feature is especially beneficial in scenarios where you have multiple WAN connections (e.g., MPLS, broadband, LTE) and need to prioritize certain types of traffic over others.

Key Concepts of Meraki SD-WAN Application-Level Path Selection:

1. Traffic Classification: Meraki SD-WAN can identify and classify traffic by application type. This means that traffic from applications like VoIP, video conferencing, cloud applications, or file transfers can be distinguished and treated according to the importance of the application to your business operations.

   Meraki uses a combination of Deep Packet Inspection (DPI) and application signature-based identification to classify traffic, making it possible to dynamically manage and route traffic at the application level.

2. Path Selection Based on Application Type: With Meraki SD-WAN, you can configure policies that allow traffic from specific applications to be routed over a particular WAN link, based on real-time conditions. This feature helps ensure that bandwidth is used efficiently and that critical applications are not impacted by lower-priority or non-business-critical traffic.

   For example:

   • VoIP and video conferencing traffic can be routed over high-priority, low-latency links like MPLS, or a high-speed broadband connection if MPLS is unavailable.
   • Bulk file transfers or non-time-sensitive applications can be routed over standard broadband or LTE connections, which may be more cost-effective but can tolerate higher latency or jitter.

   Meraki allows administrators to configure these policies per application category or even individual application.

3. Dynamic Path Selection (DPS): Meraki SD-WAN uses Dynamic Path Selection to make real-time decisions about the best path for each application’s traffic. If one link is performing poorly (e.g., high latency or packet loss), traffic can be automatically rerouted to a secondary, more optimal link.

   • Path Quality Metrics: Meraki’s SD-WAN continuously monitors key performance metrics for each WAN link, including latency, packet loss, jitter, and available bandwidth.
   • Real-Time Adaptation: If a preferred link becomes unreliable, the SD-WAN automatically adjusts by selecting a more optimal path for traffic, ensuring uninterrupted service for critical applications.

4. Traffic Shaping and QoS (Quality of Service): Traffic shaping allows you to prioritize or throttle bandwidth for specific applications. For example:

   • Prioritize high-priority apps like VoIP or video, which are sensitive to delays, by guaranteeing them sufficient bandwidth.
   • Throttle or limit bandwidth for less important applications such as large file downloads or streaming media, which are less sensitive to delay.

   You can configure policies to ensure that these applications are treated appropriately on the network, even when multiple types of traffic are competing for bandwidth.

5. Policy-Based Routing (PBR): Policy-Based Routing enables administrators to define routing policies that direct specific types of traffic to a chosen path based on the application's needs or the link's performance.

   For example, you might create policies such as:

   • Route critical applications (e.g., ERP systems, VoIP) over a dedicated, high-performance WAN link (like MPLS).
   • Route less time-sensitive applications (e.g., file backups) over a less-expensive, lower-priority connection (such as broadband or LTE).

   Policies can be configured in the Meraki Dashboard and are applied automatically to the appropriate traffic flows.

6. Application Visibility: The Meraki Dashboard provides detailed visibility into how applications are performing across your WAN. This allows you to see:

   • Which applications are consuming bandwidth on each WAN link.
   • How much bandwidth is being used by each application.
   • The real-time performance (latency, jitter, packet loss) for specific application traffic.

   This visibility is essential for troubleshooting and making data-driven decisions about path selection and bandwidth allocation.

Key Benefits of Application-Level Path Selection in Meraki SD-WAN:

1. Improved Application Performance: By prioritizing and routing traffic for critical applications over the most reliable, low-latency links, you ensure that users experience minimal disruption and higher quality for real-time applications like VoIP and video conferencing.

2. Optimized Use of WAN Links:

   • Cost Efficiency: You can route less-sensitive traffic over more cost-effective connections like broadband or LTE while reserving expensive MPLS or dedicated lines for high-priority traffic.
   • Resource Allocation: Automatic path selection based on real-time link performance helps optimize available bandwidth and prevent congestion on any one link.

3. Business Continuity and Resilience:

   • Redundancy: In the event of a link failure or degradation, Meraki SD-WAN automatically reroutes traffic over the best available path. This ensures continuous connectivity and avoids application downtime, which is critical for business operations.
   • Minimized Downtime: Dynamic Path Selection ensures that if a primary link experiences issues, traffic is redirected to a more reliable link without manual intervention.

4. Simplified Network Management:

   • Cloud Management: All SD-WAN configuration and monitoring can be done through the Meraki Dashboard, which simplifies network management. You don’t need to manually configure individual routers or appliances at each site.
   • Easy Policy Setup: Policies can be easily created and updated through a graphical interface in the Meraki Dashboard, making it simple to apply changes across your entire network.

5. Enhanced Visibility and Control:

   • Application-Level Insights: By providing visibility into application usage, you can see how different applications are impacting your WAN and adjust policies to improve overall performance.
   • Traffic Analysis: The ability to analyze traffic by application and link performance helps administrators proactively manage network resources and troubleshoot issues before they affect end users.

Example Use Cases:

• VoIP Traffic: If you have a combination of MPLS and broadband Internet connections, you can configure your SD-WAN to route VoIP traffic over the MPLS link for better reliability and lower latency. If the MPLS link experiences issues (e.g., high packet loss), the SD-WAN will automatically reroute VoIP traffic to the broadband link with minimal delay.

• Video Conferencing: Similarly, you could configure video conferencing apps to use the best available link with low jitter and high bandwidth. In the event of a network issue, SD-WAN can dynamically select an alternate path to maintain quality.

• Cloud Applications (SaaS): For business-critical cloud applications like Salesforce or Office 365, you can route traffic through the most optimal path, ensuring that users in different locations experience consistent, high-performance access.

• File Transfers: File transfers, which may not require the same low-latency performance as real-time applications, can be routed over cheaper or less reliable links. For instance, bulk file backups might be routed over a secondary broadband link, freeing up high-priority links for more critical services.