Network Virtualization & SDN

Network Virtualization defined as using network resources through a logical segmentation of single physical network.

VLANs  - Virtual Local Area Networks

VRF      -  Virtual Routing and Forwarding

MPLS   - Multi-protocol Label Switching

VPN     - Virtual Private Networks

MEC    - Multi- Chassis EtherChannels

GRE     - Generic Routing Encapsulation

VDC    - Virtual Device Contexts

VSANs- Virtual Storage Area Networks

Server virtualization has led to the development of virtual switches within the hypervisors. Virtual switches within the hypervisor allow for communication between virtual machines, communication between virtual machines and the physical network.

VMware –vSwitch

 VMware –Distributed Virtual Switch (DVS)

Citrix Distributes Virtual Switch (Open Switch)

Cisco Nexus 1000v

KVM-Linux Bridging ,Open Virtual Switch

VMware Vswitch Networking Components

Cisco Nexus 1000v Architecture

 Network Abstraction

Traditional network constructs were not designed to support dynamic workloads in highly virtualized environments

Overlay technologies allow for independent logical network to be built on top of existing ip infrastructure 

Abstraction uses overlays to present logical networks built on traditional infrastructure

Network abstraction

Virtual Extensible LAN (VxLAN) –Allows Layer 2 in Layer 3

Stateless Transport Tunneling (STT)

Overlay Transport Virtualization (OTV)

Locator ID Separation Protocol (LISP)

Network Virtualization using GRE (NvGRE)

SDN –Software Defined Network

SDN  is a dynamic and flexible network architecture that protects existing investments while future proofing the network. With SDN today’s static network can evolve into an extensible service delivery platform     capable of responding rapidly to changing business, end user, and market needs

Today’s network are defined by the BOX

• Hardware ,operating system, and applications built into a single hardware device
• Distributed algorithms between devices
• Separate Polices
• Federated Systems

The Value of SDN is the ability to provide configuration and automation of the entire network/fabric so new services and end systems can be deployed rapidly and operational cost can be minimized

Architecturally What It means 

Vmware SDN View

Cisco View of SDN