When Cisco was founded in 1984, applications like WordPerfect were simple and IP was used as the transport protocol to move data through the network. Fast-forward 31 years where applications today are quite complex and multi-tiered. For example, a user may connect to a web portal on one server, which then performs a search on a second server, returns the results, then connects to a third server for an e-commerce transaction.
These multi-tier applications create considerable east-west traffic within the data center, and, although the applications have changed, the basic concepts of networking have remained the same. We’ve now created workarounds and added complexity to make the network function with today’s applications. That is why we need Software Defined Networking solutions.
Remember when you took your Cisco Certified Network Associate (CCNA) course and the benefit of small, Layer2 networks was touted? Today, we are stretching Layer 2 between data centers. Instead of simple Spanning Tree Protocol (STP), we have multiple versions of Spanning-Tree, virtual private clouds (VPCs) and VERFs. Anyone who has looked at a running config file can attest to the complexity required for today’s networks to work with the complex applications of 2015.
If networking technology were developed to work with today’s applications — rather than what we initially created over three decades ago — the network would function very differently. The OpenDaylight (ODL) Project seeks to develop the ideal open platform for networking based on applications and technology in 2015 rather than those of 1984. The ODL Project — which is supported by over 40 companies including Cisco, HP and Brocade — is focused on shaping the future of SDN by providing a platform for developers to contribute to the creation of an open source SDN controller.
The ODL Project says that by utilizing SDN, the control plane (brains of the network) will be separated from the data plane (which forwards traffic). As such, OpenFlow must be the transport protocol that provides communication between the control plane and the data plane. Network virtualization is also under the SDN umbrella and behaves similarly to VMware in virtualizing servers. The final concept is programmability, which refers to the capability within hardware and software in the network to change.
SDN continues to evolve as vendors such as Cisco, IBM and Citrix are actively involved in standardizing OpFlex as an alternative to OpenFlow. Various manufacturers have built on and expanded SDN to provide additional functionality to meet business requirements. It’s also worth mentioning that SDN has the ability to operate over wired, wireless and WAN environments in a somewhat seamless manner.
It is my opinion that when considering the transition to SDN, it is not if it happens; it is when it happens. Much like server virtualization, old school IT professionals will be hesitant to embrace something new given the substantial learning curve. I’m confident though that when we look back five years from now, 75 percent of all networks will be virtualized with some form of SDN – so it’s best to start planning today. Let CDW with developing a road map for implementing a software defined networking solution.