Bringing the action closer to the customer with new content delivery technology


By Howard Watson, Chief Security and Networks Officer, BT Group

Have you ever wondered how your online purchases get to your home so quickly? How with the ‘click of a button’ your package arrives within a couple of days, sometimes even on the same day? Probably not - as consumers we don’t need to know how things get done ‘behind the scenes’. 

But for a retailer, this needs to be a well-thought-out plan that is quickly and consistently executed. Behind every delivery person’s ‘knock on the door’ your package will have gone through multiple ‘mini- journeys’. When your order is placed with a big retailer, it is often picked and packed from a warehouse, trucked to the next site, where it then arrives at a sorting centre, before being transferred to a delivery station closest to your house, sorted and loaded onto a vehicle and delivered to your home. 

Quick delivery is possible because of advances in logistics which take care of complex operations efficiently and reliably, and adept research that enables companies to predict consumers' purchases in advance. 

Networks are no different. When customers watch content, whether in their living room or ‘on the move’, telcos like BT need to get content from the source to the customer, in the shortest time possible and most reliable way. One of the ways we do this is using caches in our network called ‘Content Delivery Networks’ (CDNs). 

Unsurprisingly when delivering content to customers, the closer the content is to them, the quicker we can deliver it. CDNs are based on this premise - they distribute content from an ‘origin’ server by caching content closer to where end users access the internet. Just as delivery stations are strategically placed up and down the country, here at BT, we strategically place these CDN caches in our network to minimise the number of ‘network hops’ spread across the UK, to provide the quickest and most reliable method of delivering content. 

But in a world of booming content consumption, there is pressure on video and gaming providers to deliver ever faster streaming of higher quality content to end users. And, as to be expected, there are always different levels of demand between locations, so the content needs to be distributed in a balanced way to meet both localised and distributed peaks. With these multiple demands on the network and its capacity, we are exploring new network capabilities to speed up the delivery of content, whether that’s TV, movies or games, to enable the level of scalability and flexibility that will be needed to meet future demand. 

The more efficient the network, the less the capacity needed to deliver the same amount of content. It’s therefore critical that we work with content and application providers to explore new ways to efficiently deliver their products and services to our shared customers. 

As part of a number of solutions we are exploring, one technology innovation is the ‘Virtual Content Delivery Network’ (vCDN). 

Most CDN infrastructure today does not enable the level of scalability and flexibility of content caching that will be needed to meet future demand. However, vCDNs offer a more agile approach. Unlike traditional CDNs which are tightly coupled with underlying ‘fixed’ hardware, with a vCDN, software-based caches can be flexibly used at selected points, deeper in the network, to bring content closer to the ‘edge’ where our customers consume it. 

It is like building a larger footprint of delivery stations closer to where customers make online purchases, but the advantage of this technology is that the delivery stations can be flexibly ‘lifted and shifted’ to wherever you need them – to wherever the demand is. This flexibility is key to supporting workload management as content can be cached by software in a specific location for a short period of time to meet, say, sudden surges in demand for different types of content. 

And by placing the caches ‘deeper’ in the network, the number of network ‘hops’ that are needed to distribute content from the ‘edge’, are reduced. This enables network capacity to be ‘freed up’ and reduces pressure on our core network. 

This also means a speedier delivery and enables better quality and reliability for customers, whilst offering energy efficiencies to us, through a need for less physical space and lower power consumption. 

So, could vCDN help BT to support future content? 

To explore this, over the past year we’ve been running a live vCDN trial with partners, including Qwilt - a provider of CDN services that is already deployed in BT's network. Serving a variety of content, from video-on-demand and livestream TV content, to gaming downloads, the trial has successfully shown how a vCDN can enable high-levels of cache efficiency. In the trial we saw cache efficiency of 70-90% at peak times with the highest values for live TV consumption. Popular game releases also drove very high levels of efficiency. 

Here at BT, we’re excited by initial trial results. With wider collaboration, we hope the technology could play an important role in the CDN ecosystem as we look to manage the future of TV delivery over the internet.