Nortel has passed a potentially significant milestone for its Voice over Internet Protocol (VoIP) technology.

The company said Friday that the US Defense Department’s Joint Interoperability Test Command has passed interoperability testing. It is the first vendor to “pass” the standard, Nortel said.

Receiving the so-called JITC certification is required before products that support video, data and voice services can be connected to the Defense Department’s network.

The certification is designed to make sure products are “secure, operate without performance degradation in a multi-vendor environment, possess exacting levels of resiliency and redundancy to ensure reliability under duress and offer the unique military features and functionality required for national security,” Nortel said in a statement.