Green data centres were all the rage in 2007, but is the emphasis for green IT set to shift in 2008?

Companies pursuing a green technology agenda had lots to work with last year. The market demonstrated the attractiveness of the virtualisation technologies when VMWare floated for almost a billion dollars in August, while large IT vendors such as Sun, IBM and Fujitsu were all eager to demonstrate their green data centre systems.

But even as IT managers continue to absorb the case for energy efficient data centres, some analysts believe that a similar green revolution is about to hit firms' network infrastructures. Jon Collins, service director at analyst firm Freeform Dynamics, is one of them.

"The network doesn't have the best track record when it comes to green, which is ironic, given that it is an area of great potential, particularly considering the efficiency gains that could be achieved if [for example] the data was in the right place at the right time," he says. "Network efficiency reduces risk and lowers the requirement to store multiple copies of everything."

Collins foresees a time when wide area file services (WAFS) will help to reduce the storage capacity needed on the network. WAFS are a way of distributing information more efficiently around a wide area network so that only the correct data is mirrored to the right places.

A branch office, for example, might previously have stored all of its files locally, and tried to back up its own data on CDs or magnetic tapes. But using WAFS, the files can all be maintained centrally at headquarters. Utilising a mixture of traffic compression and byte-level mirroring of local data, the right files can be quickly mirrored between the two sites. This approach reduces not only the capital expenditure on branch office storage systems and the energy needed to run them, but also the operational expenditure and carbon emissions involved in sending out staff for local maintenance and support.

Companies will also need to consider energy conservation on the network as VoIP gains more traction, according to Paul Phillips, regional director for the UK and Northern Ireland at Extreme Networks.

Companies are increasingly using IP phones in their infrastructures, but these highly functional devices are computers in their own right. Many even have their own web servers. But rather than plugging these in at the wall, growing numbers of businesses are instead taking another approach and powering them directly through the network cables, using new Power over Ethernet (PoE) technology.

Phillips says that Extreme Networks is looking to support the shift towards PoE on two fronts. Firstly, the company claims it can reduce the amount of power needed per port thanks to the use of low-power handsets from Avaya, with whom it has an energy efficiency-focused partnership. Secondly, it can program its switches to turn off power to ports according to a preset schedule, meaning that phones in an office or callcentre can be turned off overnight. Avaya believes that utilising this intelligent approach to managing network energy use to power down phones between 5pm and 9am could save firms 75 per cent of the energy required to run IP phones.

Ultimately, deploying green network technologies is likely to prove as complex and challenging as deploying green data centre systems. But as electricity bills continue to climb and the energy efficiency of IT kit comes under ever more scrutiny, it may be a necessary step.