There has been considerable hype around software-defined networking since “VMworld 2013.” Unlike traditional networks where each network device has both a control plane and a data plane, Software-Defined Networking (SDN) separates the control plane from the data plane.
Doing so allows a single control plane to manage all SDN-enabled network devices, reducing administrative overhead and increasing network flexibility. Conventional networks require manual configuration of each device. A simple misconfiguration can take down a network, severely impacting business productivity. To avoid such issues, most organizations run a series of tests to validate changes before committing them to a production network. While a necessary step, each test invariably means incurring some level of project delay.
Command writing is naturally prone to human error; however, software-defined networking uses a declarative control system where the administrator defines the end result in the control plane, relying upon the network devices to respond appropriately at the data plane.
In VMware NSX, a control cluster is used for control plane services, administered by the vSphere Web Client. Configurations issued in the vSphere Web Client are then interpreted by the control cluster in the ESXI kernel and enforced by virtual switches and NSX gateways. Using this approach, complex network configurations, such as micro segmentation can be achieved much faster and with far less effort. Common issues, including link redundancy occur automatically and make concerns like spanning tree a thing of the past.
A software-defined-network is designed with cloud computing in mind. Support for encapsulation technologies, such as VXLAN and STT allows datacenters to easily span beyond normal physical limitations to include remote sites and public cloud providers. SDN controllers support a range of northbound requests from cloud systems, such as VMware vCloud, OpenStack and OpenFlow, including support for RESTful API. Using cloud automation, networks can be provisioned automatically in the datacenter or in the public cloud provider space.
In addition to network virtualization, many software defined networking solutions now include support for network function virtualization. This is an extension of software-defined T CXO Insights | | August 2015 25 CIOReview Rich Holmes networking that virtualizes common network devices. The virtualized network device appears as a physical device able to interact with both virtual and physical nodes on the network. This often requires a change in the way internal IT departments think. Instead of purchasing installing and configuring a new router, an organization can deploy a virtual router by using a management console, for example, the vSphere Web Client.
Deployment of a router at the software level takes only minutes, which saves both time and money. Rather than installing a new hardware enterprise firewall, a virtual firewall can be configured at the software level to provide additional granularity not found in a conventional enterprise firewall. And, rather than manually creating VLANs and managing access control lists, administrators can restrict traffic based on items such as host names, attributes, user identity, and even vCenter objects, including datacenters and hosts to simplify administration and reduce errors. Applications that previously required a hardware load balancer for performance and redundancy can now be deployed virtually, and which will be totally transparent to the end user.
With software-defining network functions, switching hardware is starting to look like more of a commodity-based process. Many organizations now consider abandoning expensive name brand switches in favor of white box hardware to gain greater flexibility and control at less cost.
Perhaps the greatest example of this trend is the Facebook “Wedge.”This is an open compute, 40Gbps top-of-rack switch designed and maintained by Facebook. The design uses an embedded Intel micro server inside a switch chassis, and relying upon the Facebook Open Switching System as an operating system. Facebook has offered up the design free to the community through the Open Compute Project. Catering to this rapidly expanding market, HP and Dell now offer switches with the Cumulus bare metal switching operating system, pre-installed and running on commercial semiconductors.
While most SDN providers have focused on the network core, HP has expanded its SDN strategy all the way down to the edge. Using the HP Intelligent Management Controller, an organization can manage all HP SDNenabled networking equipment via the Virtual Application Controller.
IMC even supports configuration of VMware NSX to provide a single management console that manages the entire networking infrastructure, physical and virtual, core to edge. HP also offers an “app store” for commonly deployed applications, such as Microsoft Lync. Once installed, the app automatically optimizes SDN-enabled networking equipment for the desired application. With its app store, HP hopes to reduce implementation time while increasing application performance.
Building on this trend, Virtual Computing Environment (jointly owned by VMware, Cisco and EMC) has recently released “VXBLOCK” This builds on the success of the VBLOCK converged system and adds SDN support in the form of VMware NSX or Cisco ACI, fully integrated and supported by VCE. Cisco ACI is Cisco’s SDN platform, which is based on the APIC controller and Nexus 9000 switches.
There’s no denying that software-defined-networking is revolutionizing the industry. Organizations realize greater flexibility than ever before while reducing Total Cost of Ownership. Perhaps the most unexpected trend seems to be that the greatest innovations seem to come from the most unconventional players.
