Under software control the audio stream is compressed, packetised and sent to its destination. At present Internet and native ATM calls are possible.
Work is underway to allow for communication over a variety of wireless networks .
The call control process is responsible for setting up calls and managing the resources associated with the call. There are a wide variety of options for controlling calls in a telephony system. The mobile control plane is used to allow the user to move freely. Details can be found in mobility considerations . Directory services can be used for a number of functions.