The Software-Defined Data Center
The widespread adoption of server virtualization has revolutionized the provisioning and management of applications, saving enterprises billions of dollars. However, the network to which these dynamic workloads connect has not kept pace. Network provisioning remains painfully slow: Even simple topologies take days or weeks to create. Workload placement and mobility are restricted by physical network limitations and hardware dependencies require vendor-specific expertise. Network configuration is performed manually and maintenance is both expensive and resource-intensive.
Extending Virtualization to Networking and Security
The software-defined data center moves networking and security forward by creating the same kind of software-driven abstraction layer that transformed computing. Similar benefits are achieved: Rapid programmatic provisioning, non-disruptive deployment, support for both legacy and new applications simultaneously on any general-purpose IP networking hardware and the liberation of networking services from hardware-bound constraints.
From Physical to Logical Services
In similar fashion to virtual machines, a virtual network presents logical network components—logical switches, logical routers, logical firewalls, logical load balancers, logical VPNs and more—to connected workloads.
Logical networks are programmatically created, provisioned and managed, utilizing the underlying physical network as a simple packet-forwarding backplane. As with server virtualization, any combination of logical network devices and security policies can be assembled into any topology. Network and security services are bound to each virtual machine and move with it, so workloads can be dynamically added or shifted without human intervention.
Essential Characteristics of Network Virtualization
Network virtualization provides hardware independence by completely decoupling networking components from underlying physical network infrastructure. From the end-host perspective, the physical network model is faithfully reproduced and workloads see no difference. In terms of operations, the change is transformative, enabling unprecedented automation of everything from network provisioning through deployment and maintenance.