In an interview with Computing following his presentation at the Data Centre Summit 2013 today (picture), Robert Bath, VP of engineering at major data centre wholesaler Digital Realty explained that that changes in data centres - particularly consolidation of facilities and a demand for new services - is driving a need for a new kind of connectivity between data centres.
"In the wholesale space, historically, connectivity between data centres has not been a key part of the value proposition or a required service. But we're seeing a fundamental shift on the part of the data centre owner-operator in influencing the architecture of the network", he said.
This shift, he said, is a result of data centre customers operating in a smaller physical footprint within data centres as "white space" becomes less affordable in cities such as London, and also because they are demanding more services as part of their data centre hosting contracts, for example dynamic bandwidth for cloud connectivity.
The company has worked to create low-latency links between access points in the London metropolitan area, where population densities and high rental charges are driving consolidation and causing bandwidth pressures.
"Almost every enterprise is consolidating data centres to save money and ease the management burden. This is fundamentally changing the network architecture. We are seeing three to four times the growth in data centre-to-data centre traffic as we are data centre to user traffic," Bath said.
"In the London metropolitan area we have contracted a major dark fibre ring that interconnects two of our major PoPs data centres, in Chessington and Woking, diversely back to 22 London telehouses / access networks," said Bath.
The dark fibre network, which was completed in August in partnership with Geo, is routed largely through London's existing physical infrastructure such as underground railway tunnels and the sewerage network, "for reasons of speed of rollout and physical resilience. It's safe from JCBs," said Bath.
"We also have partnerships with a number of other carriers and recently signed a network partnership with Epsilon, which operates and manages a global network exchange," Bath explained.
"That builds on the dark fibre network and brings the two PoPs data centres at Chessington and Woking onto the largest global network exchange; it's effectively an SDN type software provision network."
This low-latency pipeline to access points in London has allowed Digital Realty to create a connectivity for firms across central London that is on a par with what could be achieved in central London itself, but at a much lower cost in terms of rental premiums.
"It's not only rental price," said Bath. "It's also about arbitrage opportunities in relation to the cost of energy supply at the various locations."