Does MPLS Still Have a Role to Play in the Modern Software-Defined WAN?

Hint: You Can Get the Best of Both Worlds.

Software-defined WAN (SD-WAN) is often touted as a cost-saving technology that enables organizations to slash their telecom expenses. The savings typically comes through the elimination of multiprotocol label switching (MPLS) services, which are reliable and secure but also very expensive compared to other data transport options. However, pigeonholing SD-WAN as the “anti MPLS” solution overlooks one of its primary benefits: flexibility.

First, a little history. MPLS has its roots in traditional “leased line” telco circuits that provided a fixed path from point A to point B. Designed to improve IP network traffic performance, MPLS adds a label to the data packet header that determines the forwarding path the data should follow.

In essence, MPLS creates a virtual “leased line” by carving out a fixed path over a Layer 3 routed IP network that’s shared by multiple customers. End-user customers add virtual private network (VPN) “tunnels” to encrypt traffic, providing security.

MPLS has been widely deployed because of its inherent reliability and security. Broadband Internet, in contrast, is a “best effort” medium that traditionally has been used only for low-priority traffic or in areas where MPLS was not an option.

MPLS was great for multi-branch locations during its heyday but is limited in performance and sold at two orders of magnitude higher cost per bit. One of its limitations is that all locations need to be connected to the same service provider, which increases the cost and, in some cases, precludes its use due to lack of availability. Although generally more reliable than broadband Internet, it is manually configured and prone to performance and availability issues due to service provider configuration errors.

There are other drawbacks as well. Provisioning MPLS service or adding bandwidth typically requires significant lead time – weeks and months. And MPLS may not be available in some remote locations.

SD-WAN gives customers the flexibility to choose the best data transport service(s) for their needs without sacrificing the benefits of MPLS. Commodity broadband Internet connections — which are cheaper, more widely available and faster to provision than MPLS — can be combined to create a WAN that is highly resilient.

Customers hesitant to simply drop MPLS can create hybrid networks with commodity broadband in conjunction with MPLS. Best-in-class SD-WAN solutions continuously monitor network conditions and make automatic, load balancing routing decisions. Sub-second failover protects against service provider outages with little to no impact on the user experience. VPN tunnels with end-to-end encryption protect data as it travels over the public Internet.

Given the critical importance of the WAN to business operations, many network administrators are reluctant to move away from MPLS. And they don’t have to. Again, SD-WAN provides flexibility and choice. MPLS can be maintained for traditional data center traffic and other connectivity options added to handle Internet traffic.

Many of InSpeed’s customers have indeed used our SD-WAN solution to eliminate MPLS. They found that InSpeed and broadband provided better performance and Quality of Service than MPLS — so why pay the premium price? But that’s a business decision. We believe that MPLS still has a role to play in the modern WAN and give you the flexibility to leverage it along with other data transport options.