Which Type of Network Load Balancer Is Right for You?

The network load balancer is one of the core components in the network edge. It is connected to a private or public cloud and is responsible for distributing Internet traffic workload across the WAN (wide area network) resources. Even in high-rise networks, load balancers have a common strategy to achieve this goal, but the devil is still in detail to achieve an efficient and successful load balancing approach. In this article, we will study various types of network load balancers and compare and compare so that you can guide the purchase decision while upgrading your network. Why do you need a network load balancer to begin with?

This is a very fair question, ostensibly logical, but as anyone using a wide area network connection will soon realize that bulletproof connections are a utopian goal. It needs to be carefully designed, otherwise important network features (such as redundancy, agility, and dynamic fail-over) will not be part of a normal WAN connection service. In essence, what we are talking about is that a single shipment obtained through your service provider is prone to errors, fluctuations, power outages and power outages. These network performance issues are usually outside the control of the service provider. For example, the degradation of WAN link performance due to uplink cross-traffic or other parallel local traffic may affect the performance of mission-critical Web applications, which is not the fault of the service provider. Moreover, if you try to solve this problem by contacting the service provider, you will soon realize that this is not their concern either, because their "testing" will quickly show that everything is going as expected.

What is the alternative to having one ISP?

Well, I hope so now, you're convinced that owning a single WAN connection is risky for your business, and it can lead to high costs, especially if you have to connect to the cloud. To keep these basic Web services humming, spreading the eggs on a variety of service providers' baskets is a smart and effective strategy that can be achieved by a network load balancer. In doing so, you need to consider some important factors that will affect the ability of the network load balancer to enhance and protect the network.

Session management of your network load balancer is critical.

Web applications and services consist of a variety of sessions. Take browser session to bank site as an example. A single browser window will have many sessions between the browser and the endpoints on the Internet. If the network load balancer does not know the application-level classification, in other words, if it cannot understand and "merge" TCP sessions that belong to the bank site, it may try to load balance these sessions on different WAN links, thus providing different IP addresses to the bank server. This destroys the semantics of the application and thus destroys the browser session.

The solution is the so-called "smart load balancing ", whereby a packet session can be forced onto a single WAN link to represent an IP address for a bank server. Another more advanced approach is to use broadband binding, where the session is transmitted through the binding tunnel and is proxied from a single IP address. Therefore, application semantics are preserved, and the broadband binding process will also significantly improve session speed. Advanced modern network load balancers will offer one of these options, preferably simultaneously.

Passthrough and transparent install options are not guaranteed.

It is surprising to note that there are multiple WAN solution vendors that require you to redesign the network or use their network services (such as firewalls, UTM, IPS, etc.) with their network load balancing solutions. Fortunately, a modern network load balancer supports transparent pass-through installation without making any changes to the current network. This allows IT managers to use all other vendor options for a variety of other network services. You can choose from any brand of the supplier so that you can use the best components to build a network.

Load balancing algorithms are important as well.

Whether polling, weighted polling or other algorithms, the efficiency and effectiveness of load balancing are directly affected by the load balancing algorithm. Ideally, your network load balancer is able to carry out a real packet-level binding, that is, a packet that is able to spread the same session between multiple WAN links. Because this provides a better granularity, the network load balancer will have the best opportunity to optimize network utilization and achieve higher peak rates and WAN connection speeds.

Other intelligent overlays

There are other applications that may not benefit from increased speed, but rather "take care of" other network metrics such as latency, jitter, or packet loss. A good example of such an application is a real-time application such as VOIP, video, unified communications, or chat applications. If the network load balancer is able to identify and focus on these types of traffic to an overlay tunnel that is designed to optimize traffic based on these metrics, you will create a better quality of service within the network.

QoE (Quality of Experience) is what matters

In the final analysis, experience quality is critical from the end-user perspective. All efforts to add a network load balancer to the network edge are to maximize QoE and eliminate downtime. The modern network load balancer is equipped with application-centric overlay tunnels that facilitate packet-level routing decisions based on key metrics for each application. This improves the overall network performance and provides the end-user with a higher experience quality.

In summary:

Therefore, if you attach great importance to WAN performance and the organization’s connectivity to the cloud, the Advanced Network Load Balancer will be an integral part of your design. We outline some of the key features that should be considered in this decision.

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