Partner SD-WAN

Guest Post: Maximize SD-WAN Performance with Dynamic Multipath Optimization

Guest post by Paul Ruelas, GTT

Modern enterprises demand optimal performance from their software-defined wide area network (SD-WAN) solution — in real time, at all times — to keep both on-premises and cloud-based applications running smoothly. Even when underlying issues with WAN links arise, you can’t afford to have the performance of the network falter in any significant way when end users are relying on it to carry out essential business operations.

Basic, legacy-style forward error correction (FEC) simply isn’t sufficient to meet this need in the fast-paced contemporary business environment. Dynamic Multipath Optimization™ (DMPO) within VMware SD-WAN™ is the clearest solution to this issue across multiple industries.

DMPO: A Cut Above FEC

DMPO can be seen as an advanced realization of the FEC (forward error correction) concept. FEC has, of course, been known and implemented in various products for decades, but is most readily understood in telecommunications as a protocol for mitigating the effect of packet loss in data transmission. Within legacy telecom and networking systems, redundant transmissions permit the reconstruction of packets lost as a result of interference or poor quality.

But for today’s enterprise-scale organizations, on-premises and cloud applications place demands on networking solutions for which FEC’s blunt-instrument functionality is not ideal. For example, if you implement FEC on each individual WAN link, you can account for disruptions or quality fluctuations relating to that link. This means allocating bandwidth to improve the operating experience for every application — even those that, at any given time, may not be in use or already tolerate poor network performance attributes. This represents a clear misuse of resources.

DMPO takes into account the real-time performance of different WAN links, ensuring a robust, well-performing network even as individual WAN circuit performance fluctuates significantly (as they often do) or if the separate links are consumer-grade and would, without DMPO, experience frequent transmission rate and bandwidth issues. Additionally, DMPO helps bring stability to the traffic veering back and forth between enterprise locations, while establishing tunnels at the edge with VMware SD-WAN Gateways for reliable cloud connectivity.

Key Benefits of DMPO

Although the nuts and bolts of how DMPO works are not necessarily simple to grasp, the benefits it offers will be perfectly clear even to a telecom novice (a description which applies to many people — no judgment here!). These strengths are as follows:

Continuous Path Monitoring
This feature of DMPO involves the active and passive measurement of path performance characteristics — including packet jitter, latency and loss — within each tunnel. Continuous path monitoring ensures that you always have an accurate picture of how well (or poorly) traffic is faring in each segment of the SD-WAN overlay.

Dynamic Application Steering
Using DMPO technology, VMware SD-WAN identifies traffic according to all relevant criteria to facilitate enhanced dynamic application steering. For example, if an underlying WAN link blacks out (failing completely) or browns out (remaining online but failing to perform according to the terms of its service-level agreement), DMPO detects this issue in 300 to 500 milliseconds and immediately reroutes application traffic to an active (and reliably performing) WAN link. As a result, there is no noticeable lag in quality of service for the end user.

This characteristic is just as beneficial when all links are performing at a generally high-level but some are running better than others. DMPO gauges the real-time priority of the applications running on the network, steers applications according to the business policy, and prioritizes traffic for network-sensitive application classes, such as voice and collaboration.

Bandwidth Aggregation
This functionality chooses optimal paths for high-bandwidth operations, such as file transfers, through per-packet load balancing — without causing any issues with the proper order of packet delivery. When data arrives at its intended destination, a process called resequencing reorders packets if the load balancing knocked them out of order for any reason.

Forward Error Correction
Although we noted earlier that DMPO is a successor technology to FEC and improves on it, the latter’s approach still exists within VMware SD-WAN as something of a fail-safe: When traffic can’t be sent on an optimal path for whatever reason, the advanced remediation engine within DMPO detects and mitigates packet loss as much as possible. Meanwhile, jitter buffering and link steering mitigate signal fluctuations and surges in latency.

Smart Defaults
Within VMware SD-WAN, there are default business policies for more than 3,000 commonly used applications, informed by data aggregated over long periods of use. These provide a strong baseline for application steering. That said, defaults simply aren’t going to cut it for every single organization and every business intent. These frameworks can easily be tweaked, either in real time or at the policy level, based on what your needs dictate.

Pivotal Use Cases

Any real-time application will be more subject to issues with packet loss and jitter than one that doesn’t operate in real time. But voice, by far, is more harmed by jitter than any other app. The slightest frisson of disruption can throw a VoIP call into disarray. The  VMware SD-WAN DMPO technology uses link steering, jitter buffering and packet-loss remediation to reduce voice call degradation  to a rate of less than 1% within a sample size of 6 million calls. (Without this mitigating advantage, the share of calls with significant drops spikes to 25%.) Additionally, DMPO alleviates any loss of network performance you’d otherwise experience with a branch office in a remote geographic location with limited connectivity options.

Industries in which legacy network infrastructure is more common, such as manufacturing, can also benefit significantly from DMPO. Specifically, file transfer in computer-assisted drawing and machining (CAD-CAM) is much easier and more efficient with this advanced feature — without it, there might be significant application performance degradation associated with any packet loss, jitter or both.

The Need for MSP Support

To make the most of VMware SD-WAN DMPO and the solution’s many other estimable features, it’s best to enlist the aid of a globally present managed services provider like GTT Communications.

Imagine the following scenario: A network circuit goes down in the middle of the night, and just like that, you’ve lost the primary means of access to many of today’s critical SaaS applications from your primary internet service provider. As powerful as modern SD-WAN solutions are, there’s only so much your enterprise can do on its own in such a situation, running with greatly reduced capacity and with limited provider leverage to resolve the underlying issue. A reliable MSP, however, can help you find an alternative and restore connectivity, minimizing downtime and the risk of bottom-line losses.

GTT’s experts can also help you craft traffic-optimization policies for your organization’s singular priorities and obtain global WAN access through many different circuit types (broadband, DIA, private MPLS and cellular 4G as a backup). Moreover, our fully managed security suite is backed by one of only five security operations centers in the world that can boast a global CREST accreditation. Get in touch with us today to learn more.

About GTT

GTT connects people across organizations, around the world, and to every application in the cloud. Our clients benefit from an outstanding service experience built on our core values of simplicity, speed, and agility. GTT owns and operates a global Tier 1 internet network and provides a comprehensive suite of cloud networking services. We also offer a complementary portfolio of managed services, including managed SD-WAN from leading technology vendors.

About the Author

Paul Ruelas is Senior Director of Products at GTT. He has over 30 years of experience in telecommunications, networking, complex solution design, and product development.

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