Simultaneous advanced call control for both simple and advanced SIP user agents

摘要

Methods, devices, and systems for creating a call abstraction to enable an application to monitor and control various types of User Agents (UAs) are provided. The application may be adapted to monitor and control simple UAs that do not recognize out of dialog (OOD)-REFER signals as well as advanced UAs that do recognize and can respond to OOD-REFER signals.