Slow application performance

The lack of direct on-ramps to cloud service providers can significantly reduce cloud application performance. Fluctuating latency and data loss can affect real-time, low latency applications such as UCaaS. A lack of built-in WAN optimization or application acceleration technology can also degrade the user experience.

Overlay issues

There are always issues when a functioning configuration of the underlay (MPLS) before SD-WAN has to be reconfigured to accommodate the overlay created by some SD-WANs. This results in broken QoS, routing, and other related issues.

What’s more, there is diminished end-to-end control of SLAs across a do-it-yourself global backbone because of the separate visibility of the overlay and underlay. Because of this, it’s more difficult to correlate faults and provide minimal to no correlation between the overlay and underlay.

Complex operations and multiple proofs of concept (POCs)

Building a WAN requires contracts with multiple original equipment manufacturers (OEMs) and service providers. This can result in increased complexity. Problem resolution usually involves multiple POCs and separate contact lists for first- and middle-mile connectivity. This approach does not align with the cloud consumption model that CIOs prefer for their applications.

Advantages over a service provider

Aside from the do-it-yourself approach to WANs, some people choose to consume the WAN from a service provider. The provider then sources the technology from a box vendor. Unfortunately, this doesn’t bring about a truly seamless experience because of all the moving parts between the service provider and the technology vendor. Problems can arise between the provider’s underlay network and the SD-WAN technology vendor’s overlay. The challenges with taking the service provider approach include:

Last mile lock-in

Carriers like to lock customers into their last-mile solution rather than let them select the best option on the market. Last-mile service has the potential to create a poor overall user experience and defeats the agility of an SD-WAN approach.

Slow rollout

Delays can occur with equipment lead times, configuration, testing, and modifications in contracts with OEMs.

Poor cloud colocation

Carriers are not always colocated with cloud service providers, such as Amazon Web Services (AWS), Microsoft Azure, or Google Cloud. This makes it challenging to ensure cloud application performance and optimized regional connectivity.

Not agile

As we mentioned earlier, digital enterprises operate in an environment that requires agility. Events that require changes to the WAN include bringing out new cloud applications and taking down or migrating from legacy applications and opening and closing branch and remote locations. Legacy WANs are not able to keep pace with rapid changes.

Security

The provider may not be working with the security vendor preferred by the enterprise. The provider may also not have firsthand experience and deep support with a given security vendor.

Inconsistent SLAs

Carriers operate within specific service areas, like a single country or region. For international connectivity, peering arrangements with multiple service providers are