Middle-Tier Networks: Geographically Dispersed Organizations

For years, we have used MPLS and, more recently, SD-WAN to ensure a quality network experience for our office site users. I've noticed a lot of clients still keep their MPLS carrier service, but at a reduced bandwidth with SD-WAN overlays. This works great to deliver apps and services from centralized or regional network hubs.

In our blossoming de-centralized app and service network, the integration is achieved by landing circuits at cloud exchanges and anchoring them back to either our data center hubs or MPLS/SD-WAN for sites and users to utilize accelerated connectivity. SD-WAN vendors have offered cloud service accelerators as part of their premium subscriptions while naturally connecting to your organization’s hub/data center. We can use these tools to monitor and validate the path between the user and the destination that is not under our management. However, it can be time consuming to contact and work with the carriers along the path when an issue arises.

A middle-tier network provides local entry via a Point of Presence (POP) into a securely segmented SD-WAN on the provider side that is tightly integrated with global ISP backbones and optimized for the best path based on your traffic’s destination. Your site just forms IPSec tunnels with the POP and trades routing information for your WAN. The middle-tier network takes care of the rest. You could also run your SD-WAN overlay over the top (OTT) of some of the middle-tier networks. Remote users can take advantage of the middle-tier networks for secure access to apps and services by VPN client into hubs/POPs or cloud-hosted VPN that interconnects to the middle-tier network.

Substitute MPLS for a middle-tier network to access all of our geographically dispersed sites for a fraction of the cost. They also have the cloud service acceleration features available for access to XaaS public cloud services, as well as access into typically network-restricted countries. We have obtained all the advantages of global ISP backbone services while taking on only a last-mile connection with vendor-agnostic SASE devices at the sites. Some of the middle-tier providers will even spin up virtual network appliances to match your existing SD-WAN provider equipment. We can still use the same tools to monitor and validate the path between the user and the destination that is not under our management, with a single point to contact if an issue arises.