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VG Tuesday Tips: How SD-WAN Overcomes Last Mile Constraints

  Virtual Graffiti

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As more businesses require 24/7 uptime of their networks, they can’t afford to “put all their eggs in one basket.” Even MPLS with it’s vaunted “5 9s” SLA, has struggled with last-mile availability. SD-WAN offers a way forward that significantly improves last-mile uptime without appreciably increasing costs.

Early Attempts To Solve The Problem

Initial efforts to solve the problems and limitations of the last mile had limited success. To improve overall site availability, network managers would pair an MPLS connection with a backup Internet connection, effectively wasting the capacity of the Internet backup. A failover also meant all the current sessions would be lost and typically the failover process and timeframe was less than ideal.

Another early attempt was link-bonding which aggregates multiple last-mile transport services. This improved last mile bandwidth and redundancy but didn’t create any benefits for the middle mile bandwidth. Functioning at the link layer, link-bonding is not itself software-defined networking, but the concept of combining multiple transports paved the way for SD-WAN that has proven itself to be a solution for today’s digital transformation.

How The Problem is Solved Today

Building off the concept from link-bonding to combine multiple transports and transport types, SD-WAN improves on the concept by moving the functionality up the stack. SD-WAN aggregates last-mile services, representing them as a single pipe to the application. The SD-WAN is responsible for compensating for differences in line quality, prioritizing access to the services and addressing other issues when aggregating different types of lines.

With Cato, we optimize the last mile using several techniques such as policy-based routing, hybrid WAN support, active/active links, packet loss mitigation, and QoS (upstream and downstream). Cato is able to optimize traffic on the last mile, but also on the middle mile which provides end-to-end optimization to maximize throughput on the entire path. The need for high availability, high bandwidth, and performance is achieved by enabling customers to prioritize traffic by application type and link quality, and dynamically assign the most appropriate link to an application.

The Cato Socket is a zero-touch SD-WAN device deployed at physical locations. Cato Socket uses multiple Internet links in an active/active configuration to maximize capacity, supports 4G/LTE link for failover, and applies the respective traffic optimizations and packet-loss elimination algorithms.

Willem-Jan Herckenrath, Manager ICT for Alewijnse, describes how Cato Cloud addressed his company’s network requirements with a single platform: “We successfully replaced our MPLS last-mile links with Internet links while maintaining the quality of our high definition video conferencing system and our Citrix platform for 2D and 3D CAD across the company.”

SD-WAN Leads The Way

The features and capabilities of Cato Cloud empower organizations to break free from the constraints of MPLS and Internet-based connectivity last mile challenges and opens up possibilities for improved availability, agility, security, and visibility. Bandwidth hungry applications and migrations to the Cloud have created a WAN transformation revolution with SD-WAN leading the way.