The next generation opitimized WAN network solution will use software define along with a 7 layer approach for actual optimization of the network.


One big challenge to the optimization of WAN networks is that while running, programs are not installed at one set location (like the data center or the headquarter), but rather are designed in a hub-and-spoke or star topology approach for easy access. As such, applications often rely on cloud computing and offer web-based services. This goes against traditional security methods, where all connections are supervised via a security gate before web services.

It’s apparent that this is not the most efficient way to use bandwidth, as companies need to pay a considerable monthly fee for a quick, stable, quality and specialized MPLS link, which sadly serves only one purpose: simple Internet connection. A more realistic method is the ensurance of internet connection and web-based services at branch scale with bandwidth catered to user demand. This approach should be taken into consideration, as it will be more suitable for various WAN connection methods, all the while keeping to security policies. The WAN hybrid solution (which integrate most physical WAN connections with software-defined WANs), will be suitable for many organizations and companies.

WAN network optimization with the SD-WAN solution

A Hybrid WAN network is defined as a SD-WAN that uses the 7-layer approach to counter problems in connection, data compression, data buffer, fake protocols/optimization, multithreading, security as well as application link optimization; and at the same time utilizes mobility to balance the WAN connection, all the while meeting access demands for required web services.


The solution needs to first allow maximum flexibility for physical WAN connections, in which users can easily add accesses to WAN (from traditional MPLS – Multiprotocal Label Switching, dedicated internet connection, broadband, to wireless connections like 3G/4G/LTE and wireless satellite connections).

Current technological trends however, mean that users are now abandoning traditional technologies like MPLS for new, dedicated, Internet-based ones.

In specialized fields like finance, law, and healthcare, however, personal data security plays a vital role with enforced regulations. Thus, a dedicated network is crucial in these fields, and companies and organization needs to ensure easy and convenient connections on both the national and worldwide scale, while still following security protocols. Market trends and ever-changing demand also need to be taken into account, in order to know the need for expansion and bandwidth change, making SD-WAN one of the most efficient choices.

Opimization of the application link

This is an important task in ensuring the efficiency of the WAN network. Users should consider the effects of multiple connection types in a hybrid WAN network while choosing their suitable solution. Also, application flows should be optimized using suitable links for specific business purposes. In order to optimize the application link, software algorhithms will need certain real-time configurations of the WAN network, including latency, package loss, jitter, and bandwidth in order to create and process prevalent problems.

Despite still using WAN connection devices for physical WAN networks, the aforementioned software is the core value of WAN optimization devices, as well as the reason to the name “SD-WAN”.  As a result, it will not be transparent to end users, therefore can maintain application sessions, as well as meet the requirements for latency, readiness, security and so on, regardless of changes in applications and physical connections. It is important to note that with applications in high priority, the user demand will be placed higher in the shortlist to ensure fast connection. This is crucial to networks’ real time traffic via IP protocols like sound and visual.

So what is it that users need? Not sophisticated technical elements. Rather, they focus on specific demands like stability during working sessions, back-up elements, consistency, transparency, and ensurance of smooth business operations.

To the IT department, however, it is the opposite. Technical elements need to be clearly stated, and algorithms needs to be transparent and detailed, including all the important bits: quality of the session’s database that is needed for stable VoIP call quality, infrastructures such as electricity, back-up, LAN and WAN networks, device efficiency, mobile users, as well as cloud-based web applications. Furthermore, it is important that optimization is achieved via considering the necessity of each application: the organization should meet technical requirements while still following the set of priority.

The morden SD–WAN network is well-suited for both the IT department and the end users, and is convenient and easy to use at the same time.

Mobility of the application

In reality, the SD (Software – Define) technology is not only applied on WAN-supported devices, but also on the entire SDN (Software Defined Network). The technology follows a new software-based structure, which allows better flexibility and cost efficiency. The popularity of SDN and cloud computing options also provides user with a variety of solutions, leading to easy deployment of applications in their data centers, both on-premise and on cloud-computing.

At the same time, it is important to create a back-up site for the application, or to deploy all mentioned solutions as a preventative method. Automatically creating preventive regulations for each solution basing on demand, priority, user transparency and easy accesss for IT management is also vital. For future expansion, businesses also need to focus on API communication support solutions to ensure easy integration of the control network at TTDL.

All SD-WAN soltions require good support in configuration management and control, focused displays, easy all-system policy updates, application software, patches, non-geographical hardware & firmware, as well as customization according to different policies for different user classes, functions, and physical nodes.

Service quality of different application layers

In traditional WAN connections, the service quality depends on the next hop point, which means the information package will need to go through a lot of transactions to make its destination, leading to the possibility of package loss.

In the MPLS network, however, users can set service layers to ensure the priority of important WAN services. Here, as the application information package leaves the QoS device and move onto the internet connection, it will need to follow the Best-Effort model (or FIFO – First in, First Out) before reaching the next reception points.

Another risk lies in a QoS traditional feature – the ablilty to support establishment of multiple connections at the same location. In this, when the main connection fail, QoS policies will not automatically move to others, leading to the interruption of prioritized applications, and shall require manual recitification in order to work again.


Among all, the major concern in switching to WAN is security: direct internet connection at branches may compromise safety. However, with SD-WAN, this problem can be easily solved.

A rightful SD-WAN solution will require automatic policy updates, from centralized management points to branches, per the system settings in both the WAN network and the internet. SD-WAN devices at the branches’ nodes will integrate basic firewalls, which are able to update policies issued by the management points, ensure security, as well as control branches connection should the centralized connection be interrupted.

In order to retain network efficiency, the SD-WAN solution can establish connections on different security levels. Traffic via safe links like MPLS and Point-to-Point Ethernet can skip data encryption, while those via public Internet will be encrypted with an integrated encryption module that meets the industrial encryption criterias. Commonly, an encryption module will have 256-bit encryption, with the ability to join sessions of optimized connection channels to ensure security.

Optimizing application protocols

Even the most modern WAN networks include localized applications, leading to inefficient operations regardless of the number of connections and bandwidth. This is where application protocols come into the game.

It is during the application protocol optimization process that SD-WAN plays its best hand: optimal algorithms, balance of QoS policies, and automatic configuration adjustments that minimizes the impact of prioritized applications. Only after then will the other applications be allowed to use the bandwidth and connection.

Caches and data compression

While the SD-WAN solution provides hybrid WAN connections, the bandwidth is limited in capacity and possibly high in cost. This is why traditional methods like data compression and caches are always mentioned in all solutions, no matter how modern: the leftover bandwidth, like most other technological resources, will be utilized. As such, features like compression and caching is on at most applications, at most branches.


SD-WAN is a multi-functional, multi-connection modern solution, with integrated firewall, antivirus, and web filters. It also optimizes VPN, uses WAN connections, and balance traffic with smart centralized management displays – the ultimate smart, friendly and demand-satisfying solution to businesses and organizations alike.

Song Phuong  – FPT IS

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