Mobile phone network operator Vodafone, today demonstrated a prototype voice-over-IP (VoIP) telephony service for mobile phones using Skype, which it said it may launch in the future. Vodafone showed the application, code-named Starfish, in the future zone of its booth at the world's biggest technology trade show, CeBIT. It has yet to decide whether it will start offering consumers the service, which could eat into its traditional mobile voice telephone business. "We have not yet decided if we will launch it, or the commercial terms and prices," said Jan Holzberg, the manager for the product at Vodafone. Starfish allows a mobile phone user to see a list of buddies from various instant messaging services such as MSN, Yahoo, AOL and Skype, and send messages and make calls over the net. The calls only use the traditional wireless voice channel from the phone to the radio base station and the rest is carried over the internet, even if the call goes halfway around the world, as opposed to normal voice calls, which are routed over the traditional voice telephony network. As a market leader with over 200 million subscribers globally, Vodafone needs to defend its market share against rivals. The Starfish software on the mobile phone is essentially the same Skype software which is used by Vodafone's much smaller rival 3, owned by Hutchison Whampoa, which it launched last year in an attempt to find new customers to boost network traffic. Starfish is a sign that Vodafone, the world's top mobile operator outside China, and Skype, the world's largest internet communication company, with nearly 200 million registered users, are finally coming together. Skype is owned by eBay.