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With the digital transformation, the volume of data that goes over networks is increasing just as strongly as the number of end devices used. A trend that will continue with more and more IoT applications. This requires new possibilities in orchestration and management of networks – which will not work without automation. Software Defined Networking (SDN) promises the solution here.
As an SD data center and SD-WAN, the concept has already proven its potential. Now the technology seems to be slowly becoming a reality for local networks. The first companies are already starting to implement SD-LAN. But what exactly is behind the trend? What are the advantages of the concept? What are the hurdles in a practical implementation? Which tips and tricks help companies to implement SD LANs in practice? Where is the journey ultimately going?
The advantages of SD-LANs over traditionally managed LANs are diverse and enormous – at least in theory. Companies with several branches have previously managed their traditional LANs locally at great expense. SD-LANs, on the other hand, promise central management of the LAN infrastructure, mapping in a single dashboard and easier troubleshooting due to a more direct configuration. In this way, it is easier for IT managers to keep track of the network, to manage the end devices and to implement policies and standards globally. An SD-LAN creates an application and policy-related architecture that unites hardware and software layers. This creates self-organized and automated networks that can be operated, integrated, segmented and scaled more easily.
SD-LANs make it even easier to group users in order to grant them dedicated access only to those areas in the network that they really need for their work. SD LANs also improve the user experience. And security is already integrated in an SD LAN as part of the solution. Because the technology makes it possible to define different security rules for different users or user groups via microsegmentation. In traditional LANs, this is complicated and difficult to manage. Overall, the “health level” in the LAN is higher with SD-LAN; it can be managed more easily or more consistently and can be scaled better. SD-LANs are pioneers for further digitization, because they prevent the collapse of traditional LAN structures, which will inevitably occur.
After all, more and more end devices are to be connected via LANs: smartphones, tablets, wearables or IoT applications, to name just a few. According to Analysys Mason, data traffic over IP networks increased by 43 percent in 2017 and this growth is expected to continue by a factor of 3.9 by 2023. The majority of employees who work with PCs in companies now use laptops. You are not ready to accept blind spots in the WLAN when you move within an office building and want to collaborate with colleagues. The trend is therefore clearly towards a wireless-only strategy. In addition, many cloud applications require high network speeds. Traditional WLAN and LAN infrastructures with their current performance are not sufficient for this.
SD-WANs and SD-DCs (Software-defined Data Centers) were quickly at the top of the priority list in many companies. The concept for SD-LANs is ultimately the same, but SD-WAN and SD-DC are technically easier to implement because far fewer connections and devices are involved. At the moment, companies are only just starting to jump on the SD-LAN bandwagon and large-scale implementations have hardly existed so far. That is why the typical business case for SD-LANs is still missing, which proves the described advantages from theory in practice. One thing is clear: SD LANs are the basis for what will be reality in around five years – the central management of WAN, LAN and DC via SDN.
There is currently no tool on the market that enables SDN across all these infrastructure areas and different manufacturers. However, SDN can only exploit all of its advantages if the silo structures between LAN / WLAN, WAN and DC are broken up and the infrastructure from the cloud to the end user is consistently and end-to-end based on the SDN concept. One hurdle here is that many companies rely on best-of-breed technology: For security, in the area of switches and routers, etc. – these technologies come from different providers and are not yet coordinated from access layer to access layer: it is missing a consistent approach. That currently does not make SD-LAN attractive enough for many companies to use it. In addition, many companies are convinced that their LAN is well managed and that they are not ready to invest in new switches etc. Your LAN often simply provides access to the network. It is better to continue working with the existing equipment – and even accept security risks because there are no more current patches for it.

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The challenge with SD-LAN is to get IT to manage its network and LAN differently, even if the need is not yet given today. The situation is comparable to the transformation from PBX to IP telephony 20 years ago. PBX was outdated, but ran stable. Here, too, there was initially no business case for IP telephony and the advantages were not really recognized. Only with the growing demands in terms of collaboration was IP telephony able to establish itself, and over time the technology matured with the development of unified communications. We now have the same situation with the transformation from LAN to SD-LAN: Many companies are satisfied with what they have. The benefits of SD LANs are visible, but still too vague. But it won’t stay that way forever.
In the future, technology that is 20 years old will not be sufficient to meet the requirements of a modern, future-proof network. Even if cloud-based network management as well as hybrid and multi-cloud environments continue to increase, SD-LANs will hardly be able to do without. Because the need for the management of the local infrastructure will remain because there is always data that companies host themselves and over which they want to maintain security sovereignty.
Of course, an SD-LAN migration cannot be carried out in the short term – as a minimum, 12 months are generally to be taken into account. Companies can make a soft change and gradually replace old LAN equipment with SD LAN switches, licenses and tools. So carry out a slow-scale migration in order to avoid a later, abrupt change that is more like an earthquake. But today companies need a vision of what their infrastructure should look like in 10 to 15 years in order to work towards
it.
Companies that are now tackling this evolution will be better positioned for the future in terms of infrastructure and digitization and will manage the transformation better than those that want or have to make a clear cut later. If it is then still possible to coordinate and connect SD-WAN, SD data centers and SD-LAN infrastructures end-to-end, i.e. to dismantle the current silo structure, the SDN concept really comes into play and paves the way for further ones Digitization with its challenges. (hi / fm)
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Take a close look at what SD LANs can do today. You are currently one of the early adopters when you jump on the SD-LAN bandwagon. Therefore, you should have a long-term plan for realizing the benefits today and the future benefits of technology.
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Develop a business case for your SD-LAN – both financially and technically. User experience could also be a business case for many companies. The most obvious is probably the higher or integrated security of SD LANs.
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Be critical when someone promises you a great deal. There are providers who promise, for example, a 90 percent cost reduction in service management with SD LANs. But this is only realistic if the existing LAN requires a lot of management effort.
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Cost reduction should not be the main argument in favor of an SD-LAN, even if the cost and time expenditure are important overall. At the same time, it should be noted that there are hardly any references for large-scale implementations, so you are still a pioneer.
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“Start Small Now to Grow Big” and “Start Small Now in Big Offices”. In this way, you can quickly achieve good results with SD LANs at production sites where the seamless interaction of IT and OT is important. You are on the safe side with pilot projects and proof-of-concepts. Do not wait too long before introducing an SD-LAN, see SD-LAN migration as an evolution. Because a seismic change will be neither possible nor effective here.
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Keep in mind that the data tsunami will definitely come, and use a careful SD-LAN strategy to prepare for it. Put your focus on whether and how the whole thing is beneficial for your company.
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In the process, always keep in mind how you can bring data lakes together and how you can best correlate hybrid cloud, WAN, DC, security and LAN end-to-end. Right from the start, consider how your SD-LAN strategy will ultimately pay off. This is how you secure advantages and good results.