Prepping for the big SD-WAN migration

By now, most of us already know the compelling proposition of software-defined WAN (SD-WAN).

Since the WAN is now virtualised, we get true transport independence and unprecedented flexibility. Automatic provisioning makes hardware changes a no-brainer. Traffic can be steered based on application for intelligent path control. And of course, better security and OPEX/CAPEX is a compelling advantage when proposing the idea of migrating to senior management.

But once your enterprise makes the decision to implement SD-WAN, the question arises: how to migrate the network infrastructure with minimal disruption to business operations?

Having the right feature set is important but it is just as critical to come up with the right strategy of connecting the SD-WAN to the existing network. Changing network infrastructure can be a foundational disruption for any modern enterprise if it is not properly and professionally executed.

Painless transitioning begins with planning

With all its benefits, SD-WAN will probably spell the end of hub-and-spoke networks. However, if you do not plan for its successful implementation, then plan to experience teething pain. Instead of a smoothly software-enhanced WAN, you may end up with a software-defined headache that will take months to smooth out.

Here are some critical aspects to factor into your planning:

A hybrid WAN is all about routing traffic over multiple paths. A SD-WAN simplifies the complex management of a hybrid WAN. You can build a hybrid WAN without SD-WAN involvement, and you could build an SD-WAN that’s a hybrid WAN. The two topologies are not interchangeable but are complementary. Knowing this distinction can save your enterprise a big headache when actually negotiating with vendors.

Also, plan carefully between the options of on-premise SD-WAN, cloud-enabled SD-WAN, or the latter with backbone. Some SD-WAN solutions may not be optimally positioned for cloud integration, so know your topology requirements even before even issuing RFQs.

Suffering no disruptions during rollout can still mean different approaches. Analyse your infrastructure well, and prioritise your remote sites to determine how crucial they are for your whole operation. Then begin with migrating the less crucial sites first for a pilot. With these sites running properly on SD-WAN, important tasks can be moved to them while the primary locations undergo migration.

Do you replace MPLS wholesale with broadband, or do you leave crucial sites on MPLS and interoperate the other sites on broadband? Sometimes the best planning does not mean going for a more affordable initial outlay, especially when multiple MPLS lines for lower jitter and packet loss still have their place in mission-critical sites.

The optimal choice, in most situations, is a hybrid WAN, unifying  two different WANs of data  traffic sent over two different types of connections; traditional MPLS to the data center and broadband connections over the Internet. 

A hybrid WAN allows traffic to seamlessly flow between the connectivity modes without any loss of quality and with a great application experience. For example, if one connection is lost or experiences latency, jitter or loss of packets, the other line can take over and meet any service level agreements.

Verification and validation of the pilot and rollout phases is a given, to see how the network will perform under pressure. Also monitor the ability for remote branch traffic to leverage both public and private connectivity in an active-active connection mode. Make sure that critical traffic is being steered across the best performing paths across your WAN, while least important traffic makes use of the most cost-effective route.

In some corporate infrastructures, implementing SD-WAN as a managed service is a tricky dilemma. If IT manpower and infrastructure are limited, choose a managed SD-WAN solution to ensure a better migration and operation. In order to make a decision, you should know what any proposed managed SD-WAN entails.

·         Secure and IP-based virtual overlay network

·         Transport-independence

·         SLA of each SD-WAN line

·         App-driven packet forwarding

·         High availability using multiple WAN links

·         Centralised management, orchestration, and control

Through a managed SD-WAN, you get a seamless transition from your traditional WAN, lower costs and simpler billing mechanisms in case of multiple ISPs, as well as efficient centralised management.

However, some organisations find the on-premise self-managed approach to SD-WAN better for their unique circumstances and priorities.

With all potential challenges and considerations needed to evaluate, plan and implement a software-defined network, it would be prudent to consult vendors with deep experience, end-to-end coverage, extensive regional reach and a strong customer success track record.

Speak to us to find out more.