Whatever solution is chosen, businesses should ensure they support open standards. Such standards were critical when developing routing protocols—such as OSPF and BGP—and will continue to be important in the SDN world. These open standards allow best-of-breed for each function.
The promise of SDN is the ability to provision and scale resources to meet application requirements. All components should be software-programmable to enable control by emerging orchestration standards.
Enterprises should move as many functions into virtual machines as possible. VM-based network functions scale along with a business’ applications.
Weigh Vendor Options
As mentioned, top-tier networking vendors like Cisco, HP and Juniper are all developing their own networking virtualization and SDN strategies. In addition, now there are a host of other smaller players, including Vyatta, Adara and Big Switch, which are pushing SDN solutions. There also are some other data center players—VMware and Oracle, for example—that are buying SDN companies to expand their capabilities in the virtualized data center. There are a lot of choices out there right now.
Avoid Vendor Lock-In
Vendors that require new or specialized hardware do not get the point of SDN. Avoid products that create vendor lock-in, such as proprietary operating systems, interfaces, hypervisors and LAN networking.
Choosing a Vendor
IT staffs need to know what they’re looking for. Do they need to lower operational expenses? This requires products that can consume business intelligence information such as the cost-per-bit transported to use the least expensive resources first, the most expensive resources last, or dynamically turn on or off resources per transaction. Do they need to dynamically increase resources for higher-margin transaction and sales? That requires platforms that can dynamically devote resources to transactions based on financial priority and enforce the required SLAs. Can the vendor’s technology interact with its own capabilities as well as manage and interact with other third-party offerings? These are questions to ask.
Profile the Data Center and Network
Businesses should look at the operational performance of applications, services, systems, routers and switches. There are free tools, such as MRTG and TCP DUMP, to profile everything from applications and service functionality and execution to network device performance, and, more importantly, to highlight performance bottlenecks. Understand everything about your IT environment, including service-level agreements (SLAs), committed information rate (CIR), bit error rate (BER) and packet loss rate (PLR).
Inventory the Environment
SDN is the use of software to direct infrastructure by replacing the vendor-implemented logic on the hardware with new logic that is remote to the original hardware, such as switches. Know what software and services are running, and which consume the most compute and network resources. nProbe, nTop and SNORT are just a few free tools that can be used.
Prepare a Current Topology Map
IT professionals need to see a visual layout of their company’s data center and network, so the topology must be up-to-date.
IT Budgets and Finances
Enterprises need to know everything, from the productivity of their IT infrastructure, and what the acquisition and ongoing support costs are, to how many transactions must be supported, the cost-per-compute transaction and cost-per-bit transported, the capacity needed for each element, the mean time between failures/or uptime they require and the cost of downtime.
What does a company need from SDN? If it’s increased utilization of idle compute resources such as servers, that calls for increased use of virtual machines (VMs). Faster, more responsive service creation and deployment in virtual computing? That will need virtualizing executions instead of virtual machine migrations, which are slow, bandwidth-intensive and interfere with other services and work over limited distances. Does the enterprise need to support cloud computing? Faster performance? More transactions and a specific level of transactions? These questions need to be answered.
Some simple SDN initial steps include virtual switches and VMs being mounted on servers. Hypervisors need to be configured, rules set, and switches and their default rules created and configured. The next SDN steps are the integration of the data center and network.