Rolls-Royce is the latest company to switch its global telephone network to the internet, using voice over internet protocol (VoIP) which sends voice signals over the web in data packets just like an email. The aero-engine maker has paid Nortel $20m (£11m) to transfer its telephone network to VoIP and service it for seven years. Nortel expects to spend the next 12-16 months implementing the new system, initially for 26,500 Rolls-Royce employees. In the meantime it will also maintain the existing phone network. Tim Gower, of market analysts Datamonitor, said: "Traditionally there has been one network for voice and one network for data. Through VoIP [companies] can converge their voice and data networks, reducing operation costs by having one network to manage and maintain as opposed to two. There may also be some headcount impact." Rolls-Royce could not say whether the new move would result in any job losses. Apart from the cost benefits, employees can use the company`s VoIP services from different locations. And VoIP offers a more sophisticated telecommunications package with features such as video services. Analysts say initial concerns over the reliability of VoIP have diminished. Paul Kelly, president of enterprise EMEA at Nortel, said: "We`re delivering the same level of reliability on a VoIP platform as we would do over existing platforms," which he called "99.999pc reliable".