Why Virtualisation is more than just another buzzword
Stephen Smith, CTO Cloud, of Imagine Communications thinks it’s time for the industry to let go of tin and embrace virtualisation
The transition of the broadcast industry is bringing with it a new set of buzzwords. Virtualisation is at the heart of the transformation process: without it we cannot achieve any of the real advances. So I want to talk a little about what it is and what it means.
Consider a video server, a piece of hardware with which we have all become comfortable over the past 20 years or so. It may come in a box from a specialist broadcast supplier, but inside it is a set of IT components. A video server is comprised of storage, usually spinning disks, control and processing software, and some proprietary I/O hardware.
At this level, the only thing that makes it a broadcast-specific device is the proprietary I/O, which will generally be a number of SDI ports using coax cables and BNC connectors. If we were to transport our video and audio over IP instead of SDI, the server would not require the proprietary card, have only IP connectivity and therefore, could be regarded as an IT device.
It is important to note that even though in this context we have changed the transport from SDI to IP, we are still using a physical IT server for the function of a video server and it is still an application-specific device. Its sole purpose is to capture, store, manage and deliver in real time video and audio content.
But because we are now using a standard IT device, we could relocate that functionality to a datacentre, an environment where compute, storage and connectivity can be provisioned independently of the business function it will later be assigned. The video content could leverage the same underlying storage systems as other business functions, each segregated for performance and security. The computational aspects of our video server could be hosted on any sufficiently resourced generic IT device. This is all transparent to operators. It would still look and feel like the same discrete devices they were used to.
Virtualisation provides broadcasters with function portability. No longer are tasks required to run on specific physical resources
Virtualisation, the separation of business function from physical device, is the next step in this transformation. The resource requirements for a business function or a device are electronically defined. A machine matching this definition is then emulated by a server and the business function is then hosed in this emulated server. The business function is blind to this emulation and believes it is still running on its own server. Resources not required by the emulated machine are available to other business functions. While there is benefit in being able to reclaim this otherwise unused resource, the key benefit is that we are no longer tied to a single physical device. In the event that there is a hardware outage or maintenance needs to be performed, we can simply host our virtualised server on a different host, perhaps even in a different datacentre.
The essence of virtualisation is this ability to dynamically re-task resources to meet changing business needs. Virtualisation provides broadcasters with function portability. No longer are tasks required to run on specific physical resources.
To take a simple example, a new piece of content ingested into a server immediately needs transcoding into multiple formats. This could be accomplished very quickly by grabbing multiple resources and spreading the tasks out. Taking those resources might impact the performance or expedience of less important business processes but these can recover as soon as the transcode jobs are complete and the resources returned to the shared pool.
That is the key to virtualisation: it makes systems highly elastic. You can scale resources up and down effectively instantaneously, maintaining high utilisation of the hardware. Virtualisation makes one other important concept practical. If we accept that we move our broadcast processes out of dedicated boxes in our machine rooms to virtual machines in a datacentre on the other side of the building, then we could equally move them to a datacentre in another building. A network of television stations could concentrate its graphics processing at its headquarters, for example.
And if virtualised datacentres can be remote from the operational site, then what is to stop us from putting the virtual machines in third-party businesses which exist for that purpose: cloud service providers. The cloud is simply virtualisation and outsourcing combined.
Software-defined networks are heralded as the future of broadcasting because they enable new architectures that are controlled by software processes, which in turn call on other software processes to start or stop to meet our minute-by-minute needs, whether those processes are themselves triggered by automatic workflows or by pressing buttons on conventional control panels. Virtualisation is what makes it possible.