Broadband ISP BT Trials Improved UK Content Delivery Network

Customers of UK telecoms giant BT may be interested to learn that the ISP has been conducting trials of a new Virtual Content Delivery Network (vCDN), which uses software-based caches that can be flexibly used at selected points, deeper in the network, to bring content (video etc.) closer to the “edge” where their users consume it.

Most broadband and mobile operators use sophisticated Content Delivery Networks (CDN) and systems to help manage network load, which caches popular internet content closer in the network to end-users (i.e. improves performance without adding network strain). Such systems also help to lower the provider’s impact on external links and keep bandwidth costs down.

However, BT complains that most CDN infrastructure today “does not enable the level of scalability and flexibility of content caching that will be needed to meet future demand“, thus they see vCDNs as a solution that could offer a more agile approach.

Unlike traditional CDNs which are tightly coupled with underlying ‘fixed’ hardware (i.e. they’re inflexible), 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 their customers consume it. The ISP has been trialling just such a solution and appears to have been “excited by [the] initial … results“.

Howard Watson, BT’s Chief Security and Networks Officer, said:

“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, BT says they saw cache efficiency of 70-90% at peak times with the “highest values for live TV consumption“, while popular video game releases also drove very high levels of efficiency. Indeed, it’s not uncommon for major game releases these days to be 50-100GB (GigaBytes) or more in size, which is something that a more adaptable vCDN might be able to help with.

BT doesn’t set out their plans for a full adoption, but they do believe that “wider collaboration” will be needed to help the technology “play an important role in the CDN ecosystem as we look to manage the future of TV delivery over the internet.”