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What is WAN Aggregation?

WAN Aggregation Definition

Wide Area Network (WAN) optimization can greatly benefit enterprise networks, especially when it comes to reducing the repetitive use of bandwidth by applications looking to access images, documents, and other types of files that can take advantage of caching. This is not the only option for improving edge connectivity, though – there is also WAN Aggregation. Both approaches have a place in boosting the power of your business's software-defined wide-area network (SD-WAN), but as you will see, WAN Aggregation addresses a different set of issues and accomplishes connectivity goals in an entirely different way.

WAN Aggregation, Defined

WAN Aggregation is the practice of bundling – or aggregating – two or more ethernet links together into a single logical connection between two devices, with traffic spread evenly across these links.

Another term for WAN Aggregation is “link load balancing,” which refers to the even distribution of traffic among the various bundled links. The term “multilink aggregation” can also be used as it conveys roughly the same meaning – combining an ethernet port with another to balance competing demands without experiencing lags in performance.

When considering this definition, it is essential to note the difference between WAN and Local Area Network (LAN) aggregation. LAN aggregation is associated with a home network, and these connections can affect the devices that are connected to the router. WAN Aggregation, on the other hand, is associated with a cable modem. Because the connection between a device and this modem is not affected by geographical location or other devices, an aggregated WAN connection provides seamless connectivity and the full speed of one’s Internet Service Provider (ISP).

How WAN Aggregation Works

By combining multiple network connections in parallel to leveraging under-used links, spreading traffic evenly across those connections, and increasing bandwidth through each WAN port, businesses can see improved performance with WAN Aggregation. The active monitoring protocol that enables devices to aggregate these links is known as Link Aggregation Control Protocol (LACP), which can be configured in either an active (always live) or passive (idle until needed) mode.

Switches should be top of mind for businesses when it comes to WAN Aggregation, especially those that offer support for LACP to handle connections. These devices operate at the Data Link layer of the OSI reference model and connect computers and servers into a single network. By creating a daisy chain-like connection between switches, businesses will ensure not only connectivity between devices but also more effective bandwidth throughout.

How WAN Optimization and WAN Virtualization Differ

If businesses have heard about WAN Aggregation, it is more likely than not that they have also heard of WAN Optimization and WAN Virtualization. While each of these processes can help improve edge connectivity, the issues they address and the ways in which they accomplish their goals are distinct. 

WAN Optimization, for instance, works by caching or compressing data to pass more of it through the IP pipeline, thus reducing the volume of traffic across the WAN. For businesses that rely on real-time applications, such as streaming videos, though, WAN Optimization will not offer the greatest value. This is because the data packets within these applications are already compressed as much as possible, meaning there is no need for further action to be taken; this is also the case for encrypted traffic since it cannot be cached or compressed. Scenarios such as this are where WAN Aggregation demonstrates its value, as it does not employ caching or compression, but rather opens up more IP lines, diversifying connectivity over multiple ISPs.

Another buzzword is WAN Virtualization, which is an emerging technology that allows bandwidth from multiple unique sources to be introduced at each location, creating a robust WAN fabric between remote networks and the data center. These types of deployments can add value on top of existing WAN Optimization deployments via bandwidth aggregation and loss-mitigation capabilities.

Difference between WAN optimization and WAN virtualization

Applying WAN Aggregation to SD-WAN

At its core, SD-WAN is designed to improve application performance and increase agility. By adding aggregation to the mix, businesses can further enhance their edge connectivity. Tunnel bandwidth aggregation, specifically, maximizes bandwidth use, ensuring that applications can perform at their best levels without hindering the performance of other applications that are also competing for bandwidth.

Furthermore, as part of an SD-WAN solution, WAN Aggregation improves throughput between locations. Should one or more of the links that are aggregated happen to fail, the others will pick up the load, keeping applications accessible for a seamless user experience – this is known as redundancy. 

How Fortinet Can Help

Fortinet is committed to improving SD-WAN environments with advanced capabilities, including WAN Aggregation, for improved performance of business-critical applications. Fortinet’s SD-WAN also supports aggregation with on-demand detection and reporting of WAN bandwidth.

In a world where digitization is vital and application performance is directly tied to productivity, your SD-WAN should do more than simply provide connectivity – it must also bring speed, flexibility, and security to the table. Fortinet Secure SD-WAN does all that and more, optimizing the SD-Branch experience with techniques like SD-WAN Aggregation for high-level application performance and reliability in your next-generation branch environment.

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Improve user experience and simplify operations at the WAN edge with an integrated next-generation firewall (NGFW) and SD-WAN in a single offering.


What is WAN Aggregation?

Wide-area network (WAN) aggregation involves combining two or more network connections, often from different internet service providers (ISPs), in parallel. WAN aggregation is also referred to as “link load balancing” and “multilink aggregation.” In an aggregated WAN setup, the speed of the traffic from your ISPs is spread evenly across the connections.

What is a WAN Aggregation Router?

A WAN aggregation router is designed to accept two or more internet signals through ports in the back. Each port can handle a specified amount of bandwidth. For example, if a router has two ports that can handle 1Gbps each, the WAN aggregation router can supply your organization with a total of 2Gbps.

How to set-up WAN aggregation

The specific steps to set up WAN aggregation depend on the make and model of your router and modem. However, in all cases, you connect to your WAN aggregation-capable router and activate the option for WAN aggregation. Then, you need to log in to your modem's admin page and configure it for WAN aggregation.

What is WAN port aggregation?

WAN port aggregation refers to when multiple WAN ports are used in parallel in a WAN aggregation setup. Each port receives its own signal from an ISP. The signal is then sent to the networks and devices that are connected to the WAN.

Does link aggregation increase speed?

No, link aggregation does not increase the speed of the incoming signal, nor does it increase the overall speed available to users of the network. However, WAN aggregation can increase the throughput of the signal, giving users access to more consistent bandwidth. This may result in endpoints experiencing faster or smoother performance.