SDN explained
Data centers, carriers and enterprise centers are becoming increasingly complex in a world that demands greater agility. Existing networks are not designed to be dynamic, making it difficult for them to respond to change. In an effort to address shifts in traffic flows and services, software-defined networking (SDN) was developed.
SDN is a burgeoning architecture that enables network behavior to be centrally controlled through application program interfaces (APIs), or open programmatic interfaces like OpenFlow. With software-based control, network administrators can direct traffic flows from a centralized console and provide services throughout the network regardless of the connected hardware components.
The architecture of SDN
From a bird’s eye view, SDN consists of a bottom, middle and top layer. The bottom layer is the infrastructure layer, which houses network forwarding equipment. The middle layer is the control layer, which is responsible for configuring the infrastructure layer. It charts service requests onto the infrastructure layer in the most optimal way possible. The application layer is where business, cloud and management applications send requests for the network onto the control layer.
SDN helps abstract lower level functions and move them to a normalized control plane. With SDN, the layers and APIs in-between them are open. This allows multiple vendor equipment at the infrastructure layer, multiple vendor components of control at the control layer and multiple vendor applications at the application layer. The control layer can make intelligent decisions on how to best configure the infrastructure of the network.
Advantages and disadvantages
SDN has several advantages for customers who have rapid changes in their everyday network load, such as social network sites and internet search engines. It enables service operators to slash operating costs through inexpensive switches that can perform automated functions. In addition, IT managers can test run various network configurations without disrupting the actual network. Furthermore, the centralization of the forwarding information base (FIB) allows optimal routes to be calculated for traffic flows across the topology.
Moreover, SDN can filter packets as they enter the network. The switches act as basic firewalls at the edge of the network. These switches can redirect suspicious traffic flows to higher layer security controls, including intrusion prevention systems (IPS) and application firewalls. One drawback of centralizing security is it serves as a bullseye for attacks; nevertheless, it can guard against security threats throughout the network when setup correctly.
SDN is not without its disadvantages, however. The problem with SDN implementation is it requires completely changing a network’s infrastructure. Service providers have to alter their network, retrain staff, and learn new management and diagnostic tools. For many providers, the costs latched to SDN implementation do not outweigh the benefits. What is needed is a tool to centrally manage the network that covers installation expenses.
The way of the future
SDN is a multilayer program that enables users to optimize every level of their network. The software architecture can help networks configure themselves to channel resources swiftly and effectively. Despite these benefits, several businesses have yet to deploy it due to installation drawbacks. Interest is expected to grow when users can purchase solutions that allow them to manage SDN. To learn more, watch the video blow.
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