Technology - SD-WAN

Software-Defined Networking (SDN) and Software-Defined Wide Area Networking (SD-WAN) have reshaped networking from static, hardware-centric networking equipment to agile, cognitive, and software-driven networking solutions. Routers and firewalls no longer need to have custom silicon but rather can be implemented on architectures based on off-the-shelf x86 hardware. This new paradigm enabled services that can be delivered via networking software and other network services that are built on top of these commodity hardware enabling SD-WAN solutions.

SD-WAN includes localized common service components such as firewall, NAT, DHCP and others. SD-WAN endpoints can communicate with other SD-WAN endpoints via SD-WAN overlay tunnels. These SD-WAN overlay tunnels constitutes an important key component of any SD-WAN solution as it dictates how multiple WAN connections are stitched together to create an efficient and agile internet connection for the location.

These SD-WAN overlay tunnels, similar to traditional VPN tunnels, with two primary and important differences:

1) SD-WAN, unlike traditional VPN, is capable of aggregating two or more WAN resources within the tunnel.

2) SD-WAN, unlike traditional VPN, is capable of implementing sophisticated algorithms that can steer IP packets between WAN paths for better performance and reliability.

As an example, Broadband Bonding is a specific type of an SD-WAN overlay tunnel, that has the ability to monitor various parameters on the individual WAN transports (such as latency, packet loss, jitter, throughput and various other parameters) and make intelligent per-packet routing decisions to enable aggregation of WAN links for a fatter IP tunnel that can be utilized even for a single flow.

Another example of an SD-WAN overlay tunnel is the VoIP Armor, whereby the SD-WAN tunnel optimizes the Voice-over-IP packets for the parameters that matter most for the VoIP application, namely, the Mean Opinion Score (MOS).