Over the years, organizations have introduced SDN into their networks. SDN has been introduced because of its benefits, and the upcoming sections highlight the most prominent real-life applications of SDN in networks and how they have been adopted.
Data centers support traffic and applications that have diverse resource requirements ranging from high-bandwidth to security. The present day network architecture is rigid, which restricts the overall utilizable resource provided by the equipment in the data center. Considering the underlying principle of SDN, applications with specific needs can be deployed on an SDN infrastructure.
SDN can support multiple network instances on a single forwarding element, allowing maximum utilization of network resources, as shown in the following diagram. This feature supports the multi-tenancy requirement of future data centers:
SDN also supports the micromanagement of the traffic traversing through the data center, as unique security policies can be assigned on the basis of the packet. Finally, with the rise of cloud-based applications, SDN supports the need for timely and dynamic allocation of redundant resources for maximum delivery of services per time.
Campus networks have evolved over the years with more complexity in technology and management introduced in them to support the growing user base. The initial architecture of campus networks was characterized by the finite number of nodes that were application-centric, such as firewalls and load balancers. Growth in the campus required a very complex network architecture, which could comprise hundreds of nodes.
In earlier campus network deployments based on traditional networks architectures, there existed a rigid foundation that required support for mobility, security, multiple devices, and variants of application packets. SDN comprises the best approach to tackle the ever-evolving networks present in campuses. For instance, campus networks require many policies considering the diversity of users present. SDN deployed with OpenFlow allows the provision of these policies across the network from the centralized controller.
SDN deployed on campus networks allows packet-level wide-visibility of traffic traversing through the network nodes per time. Network analytics grants the network administration access to analytics and thorough visibility of the network. In proactive network management, network administrators, upon reviewing analytics results, can deploy policies to maximize bandwidth allocation using the load balancer app existing in the north plane of the controller.
Service providers have witnessed a high growth in the total user base in the last decade; the mobile growth rate of smartphone users, year on year, was approximately 12.1% from 2015 to 2016, which was a significant growth with respect to the infrastructure required to service the new users. SDN comes with a great potential to solve these issues faced by service providers.
The implementation of SDN for service providers comes with certain stringent requirements. SDN should be able to provide high availability (HA) and performance coupled with support for diverse forwarding elements as well as be able to accommodate various applications northbound of the controller. In addition, network virtualization should be supported in the SDN flavor used by service providers. Here, it is expected that the SDN architecture allows customers services (such as firewalls, Intrusion Detection Systems (IDS), and Virtual Private Networks (VPN)) to be virtualized compared to traditional networks that require you to introduce middle appliance boxes.
Some service providers have been implementing SDN into their networks. AT&T, which is a pioneer, has seen benefits in the support of innovation, agility, and cost. AT&T program Domain 2.0 aims to control and virtualize 75% of its network using SDN methodologies by the year 2020. For more information, you can visit http://features.zdnet.com/huawei/huawei-the-carrier-challenge#transform-the-business. NTT communication has introduced SDN/OpenFlow solutions into its networks. Overcoming the 4000 VLAN limitation is one of the greatest benefits it can boast about.
Projections exist that service provider's investment in SDN and NFV will account for a revenue of over $18 billion over the years 2016-2020.
Mobile networks have been posed with various challenges over the years, which includes network flexibility and management. The management of the network has been a difficult task because of the diverse customer segments it supports and the Operations Support Systems (OSS) and billing support systems tools used for billing the subscriber.
SDN promises a significant boost in network management and flexibility because of the support for more granular traffic monitoring and dynamic bandwidth allocation. Network congestion, a critical challenge posed to a service provider, is addressed by SDN because the controller can optimize the various northbound apps in accordance to the network traffic in real time.
A striking advantage of the SDN implementation is multitenancy. It allows multiple mobile operators to utilize the same physical infrastructure. With SDN, this will be intelligently supported because the OpenFlow controller will support the application of granular policies to their traffic by multiple mobile operators.