Cisco has filed an appeal with the European Commission asking officials to reconsider their approval of Microsoft's proposed acquisition of Skype.
The company said that its filing, made in partnership with VoIP firm Messagenet, was an effort to protect users from the possibility of vendor lock-ins which would limit calls to customers on a single platform.
"Imagine how difficult it would be if you were limited to calling people who only use the same carrier or if your phone could only call certain brands and not others," Cisco senior vice president of emerging business, Marthin De Beer, said in a company blog post.
"Cisco wants to avoid this future for video communications."
The company argues that the deal as it stands does not contain adequate protections for users and fails to guarantee any sort of interoperability standard which would let customers place VoIP calls to users on different platforms and providers.
Microsoft created a splash last year when it announced its intent to acquire Skype for $8bn. The deal, which is expected to provide a significant boost to Microsoft's enterprise communications products, was approved by the EU last October.
Cisco maintained that it was not opposed to the deal in principle, but rather that it wants to see tighter conditions placed on Microsoft.
"We respect the European Commission, and value Microsoft as a customer, supplier, partner, and competitor," De Beers explained.
"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."
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