Usually as I begin to understand the "How" of a particular technology, I am able to piece together the "Why". In configuring and understanding NVP, I started to notice parallels to messaging used in the early days of VMware to explain to customers the "Why" of virtualization. Does anyone remember this slide ?
I think these four fundamental benefits can also be realized and are relevant in the context of network virtualization leveraging Nicira NVP. Lets go through them and see if you agree.
- Partitioning - Enables an underlying Layer 3 physical or transport network to be carved up into isolated Layer 2 segments or logical networks for individual tenants or application tiers.
- Isolation - Provides separate Layer 2 Broadcast domains in logical space otherwise known as logical networks which are completely separate from other logical or physical networks.
- Encapsulation - A distributed Flow table on each transport node can encapsulate a complex network configuration for a VM from L2 to L4. In traditional networking architecture, this configuration or state would normally exist across multiple networking devices including switches, routers, and firewalls, Encapsulation could also refer to the tunneling mechanism used by the solution but this is only one piece of the NVP solution.
- Hardware Independence - The abstraction of the physical or transport network and the ability to provide the same functionality at the logical layer eliminates the need for much of the functionality previously provided by specific vendors at the Physical network layer. Of course you are dependent on the underlying physical or transport network so you still need to provide a resilient and performant Layer 3 Networking fabric but you are less dependent on specific vendors or features.