Virtualizing the network forwarding plane

Modern system design often employs virtualization to decouple the system service model from its physical realization. Two common examples are the virtualization of computing resources through the use of virtual machines and the virtualization of disks by presenting logical volumes as the storage interface. The insertion of these abstraction layers allows operators great flexibility to achieve operational goals divorced from the underlying physical infrastructure. Today, workloads can be instantiated dynamically, expanded at runtime, migrated between physical servers (or geographic locations), and suspended if needed. Both computation and data can be replicated in real time across multiple physical hosts for purposes of high-availability within a single site, or disaster recovery across multiple sites.