The energy and carbon savings achieved by firms consolidating their datacentres and promoting home working could be undermined by a drop in productivity unless the right systems are installed to cope with the change in IT infrastructure.

That is the stark warning from Brian NeSmith, president and chief executive of network appliance specialist Blue Coat Systems, who yesterday argued that many firms undertaking datacentre consolidation projects to limit their energy use were failing to account for the subsequent impact on application performance resulting from the greater geographical distance between the datacentre and the end-user in the branch office.

"There is a strong trend towards datacentre consolidation at the moment, but that tends to result in users being more distant from the server running the application, which leads to longer latency times transmitting data and performance issues," NeSmith explained. "The problem is often not detected until after the project is complete, but the fact is that a lot of business applications designed to run on local area networks (LANs) with short latency times are not optimised for wide area networks (WANs) with longer latency times. "

According to NeSmith, in some cases the latency time for sending data from a datacentre overseas to a branch office could cause the application to fail. "If you are opening a large PowerPoint file, for example, then the network might have to undertake 300 to 400 roundtrips to the datacentre," he said. "If you multiply those trips by the latency time caused by the data being transmitted over a large distance then you can have serious problem."

The same problem could also afflict home workers looking to access corporate systems from remote locations, he added.

Blue Coat Systems claims its network appliance helps tackle the problem by automatically optimising protocols to suit WANs and holding data that does not need to be sent over the internet on the local client device.

NeSmith predicted growing interest in such WAN optimisation technologies from companies increasingly committed to gaining the cost and environmental savings that come from consolidating datacentres.

"We are still early in this datacentre consolidation trend, so few companies have encountered the latency problem," he said. "But the long-term predictions are that with firms looking for cost and energy savings, they will end up with just two datacentres globally – one primary and one for back up – and they will have to deploy new approaches to limit latency issues if they want to get the benefits from this strategy."