OpenADN: A Case for Open Application Delivery Networking

Abstract

There are two key issues that prevent Application Service Providers (ASPs) from fully leveraging the cloud "advantage." First, in modern enterprise and Internet-based application environments, a separate middlebox infrastructure for providing application delivery services such as security (e.g., firewalls, intrusion detection), performance (e.g., SSL off loaders), and scaling (e.g., load balancers) is deployed. In a cloud datacenter, the ASP does not have any control over the network infrastructure, thus making it hard for them to deploy middleboxes for their cloud-based application deployments. Second, modern services virtualize the application endpoint. A service can no longer be statically mapped to a single end host. Instead, the service is partitioned and replicated across multiple end hosts for better performance and scaling. In enterprise datacenters, service requests are intercepted by an application-level routing service (APR) in the data plane and dynamically mapped to the correct service partition and the best (e.g. least loaded) instance of that partition. However, although multi-cloud (or Inter-cloud) environments allow ASPs to globally distributed their applications over multiple cloud datacenters leased from multiple cloud providers, ASPs need support of a globally distributed APR infrastructure to intelligently route application traffic to the right service instance. But, since such an infrastructure would be extremely hard to own and mange, it is best to design a shared solution where APR could be provided as a service by a third party provider having a globally distributed presence, such as an ISP. Although these requirements seem separate, they can be converged into a single abstraction for supporting application delivery in the cloud context. A sample design of this abstraction is OpenADN, presented here.