Choosing paths to SDN

We have seen a lot of early uptake in financial organisations, cloud and host providers as well as Web 2.0 organisations. In all instances, these organisations have large-scale, agile data centres which can really benefit from the cost reductions and increased control and manageability which an open source approach to SDN offers. It is from these industries that we are seeing the use cases.

For other businesses where an open source skillset is lacking, legacy networking architecture is too expensive to replace wholesale or networking is not a key priority for IT, more gradual paths of SDN migration are better suited.

TRP: What are the other paths available for businesses looking to move to SDN?

The SDN path we see the most activity in at the moment is the one being driven by virtualization companies like VMware and Microsoft; based on a hypervisor-based network virtualization model usually referred to as NVO (network virtualization overlay).

In this model, much like server virtualization, the introduction of virtual switches allows an organisation to run multiple virtual networks on a single physical network, while each virtual network retains the characteristics of running as a physical network.

We have been working closely with both VMware and Microsoft as this virtualization technology progresses – the new Dell S6000 switch is the first VMware NSX capable switch in the market – and whilst progress towards adoption will be quite gradual over the coming year, the virtualization route does inspire confidence from vendors due to the previous success in virtualization within the server.

The third approach encompasses a programmable framework where individual switches retain their control plane functions yet through an Application Programming Interface (API), allow control of the switch's local data plane functions.

Lots of large organisations still rely on legacy networking architectures which would be far too expensive to rip and replace in its entirety and this approach has the main advantage of making use of existing infrastructure alongside new interoperable networking technology which is phased in slowly.

As part of our strategy to offer multiple paths to SDN and support these legacy-reliant customers, Dell switches offer SDN capability whilst providing interoperability with legacy programmatic interfaces including Telnet/CLI, TCL, REST, SNMP, Perl and Python scripting, and the upshot of this is that these large organisations can bring in these APIs for SDN through this gradual yet painless integration.

TRP: What issues do you see customers and vendors facing when choosing a path towards SDN?

DV: As SDN is very much in its infancy, trust from customers is essential to foster. SDN is an exciting new step for networking, but reservations are natural in an industry which by nature prefers tried and tested technology to invest in.

Whilst the benefits of adoption are well speculated taking the leap and making investments requires faith in the ability of the chosen vendor to deliver. This process is further complicated in instances when a specific migration path is suggested by vendors that threaten to lock customers into specific upgrades.

Proprietary solutions carry the inherent risk of taking the customer down a route which eventually transpires to be less cost effective, yet locks the client in, so that moving to a different solution presents an even greater cost barrier. In SDN especially, as such a distinct sea change to previous networking practices, customers are more likely to want to see the whole lay of the land before investing.

The onus therefore falls onto vendors to develop paths to SDN which provide a level of confidence and security for their customers.

Trust is best established if customers know that their best interests are always being served and we believe that the best way to do this is to give them the choice, through our technology, to pursue any path to SDN they want, whilst creating the interoperability in our devices to allow them to alter their positions and tactics depending on changing needs.