Cisco today appealed the European Commission's approval of the Microsoft/Skype merger to the General Court of the European Union.

Messagenet, a European VoIP service provider, has joined Cisco in the appeal.

"Cisco does not oppose the merger, but believes the European Commission should have placed conditions that would ensure greater standards-based interoperability, to avoid any one company from being able to seek to control the future of video communications," said Marthin De Beer, head of the company's video conferencing division.

"This appeal is about one thing only: securing standards-based interoperability in the video calling space. Our goal is to make video calling as easy and seamless as email is today. Making a video-to-video call should be as easy as dialing a phone number. Today, however, you can't make seamless video calls from one platform to another, much to the frustration of consumers and business users alike," he added.

For Cisco Systems, the Skype deal creates a serious challenger to its WebEx service, one of the most popular teleconferencing platforms.

Cisco argues that the Commission should have required Microsoft to guarantee open standards for video conferencing, similar to what exists for mobile phone calls.

Such standards would eventually allow WebEx users to make calls to users of Skype and other services like Google Voice.

De Beer said that without these standards, Microsoft could "seek to control the future of video communications."