- The CSTA protocol is based on call normalization standards that date from 1992. It creates voice data connections that are not dependent upon a single type of network connection.
- The CSTA protocol supports making and answering VoIP calls, call holding, call transferring and group consultation calls. It also has a number of logical phone features, such as a Do Not Disturb mode.
- Using the CSTA protocol, applications can enable a number of features. These include graphical user interfaces for call making, messaging over different mediums (such as instant messages, emai, and SMS messaging), call routing based on predefined rules, and call logging.