Supports multiple connection types – MPLS, Internet, Long Term Evolution (LTE), etc.
Allows for dynamic path selection to share loads across WAN connections
Provides a simple interface for WAN management and is easy as a home Wi-Fi to set up
Must support Virtual Private Networks (VPNs), and other 3rd-party services like firewalls, gateways, etc.
MPLS is a protocol for shaping and increasing the speed of network traffic. It uses ingress routers at a service provider’s location to forward network packets at the switching level (layer 2) instead of having to pass them up to the routing level (layer 3). Then the egress router removes the label and forwards the original IP packet to its final destination. Time is saved, thus improving performance as the switches don’t have to look at the IP header to transmit data.

MPLS is Defined by These Characteristics
Supports multiple connection types – Internet Protocol (IP), Asynchronous Transport Mode (ATM) and frame relay
Created to eliminate the need for lookups in routing tables and increase network traffic speeds
Used to improve Quality of Service (QoS) by defining label-switched paths (LSPs) that can meet specific service level agreements on traffic latency, jitter, packet loss and downtime
Supports traffic separation, the creation of VPNs, virtual private LAN services (VPLS) and virtual leased lines (VLLs)
SD-WAN enables enterprises to use software across the internet in place of their current MPLS or other existing connections. As with all software-based installs, SD-WAN is very scalable and quick to provision. Also, it provides the ability for many WAN paths to be used simultaneously. SD-WAN allows companies to consolidate control of all WAN traffic and ensures users have improved application visibility and consistent performance. Software-Defined WAN can even decrease the costs of network administration, connectivity and equipment. (TechTarget)

With all the benefits offered by SD-WAN, it might be appear to be a threat to the MPLS market. However, SD-WAN gives cloud service providers the opportunity to offer a hybrid approach for businesses, with several different types of managed or virtualized network functionality. Using the MPLS protocol with the SD-WAN methodology, a good partnership can be formed. For instance, an SD-WAN setup can use MPLS to move high-priority packets and can then choose to send lower-priority packets across the general internet. Working together, networking costs are reduced while retaining the continued ability to define network paths where necessary. And an MPLS network can provide the network security required in an SD-WAN solution.