Employees who indulge in recreational instant messaging, gaming and downloading during work hours could be in for a shock.

Exinda Networks has announced a new capability for its wide area networking optimisation appliance which it claims can control a range of encrypted recreational internet traffic that has hitherto slipped past corporate firewalls.

The new feature blocks or slows recreational encrypted peer-to-peer traffic, ensuring that business applications are not negatively affected by work-time surfing.

The appliance will save businesses money and make employees more productive, according to the company.

Exinda claims to be the only Wan optimisation vendor that can detect, classify and control more than 1,000 applications, including encrypted peer-to-peer traffic.

The company cited Skype, BitTorrent, MySpace and Facebook as among the most common web applications that send encrypted peer-to-peer network traffic over corporate networks.

Nearly two thirds of IT professionals witness unauthorised use of company networks for instant messaging, while 58 per cent report unauthorised use of peer-to-peer file sharing, according to a survey conducted by Ashton, Metzler & Associates.

"The recreational use of Skype and BitTorrent has become a serious problem for companies and service providers," said Con Nikolouzakis, chief executive at Exinda Networks.

"These recreational applications have a way of making business applications run as if they were in slow motion.

"They have been known to crash the network in some instances. It is disruptive to employees and adds unnecessary expense to operate the corporate network."

Nikolouzakis added that there are situations where encrypted peer-to-peer traffic is used for legitimate business purposes, such as conference calls hosted on Skype.

In these instances, it is important to be able to detect and prioritise this traffic rather than restrict it. Until now, Wan optimisation vendors have fallen short on properly handling encrypted peer-to-peer traffic, according to Nikolouzakis.

Current Exinda subscribers can obtain the newly upgraded appliances on 3 December free of charge as part of a firmware update.