ECharts for SIP servlets
Thomas M. Smith, Gregory W. Bond · 2007
The development of telecommunication applications that require multiple call legs is often complex due to their event-driven nature as well as the significant amount of state that must be maintained. In general, the state associated with different call legs within an application instance differs and must be separately maintained; in addition, (non-call related) application state is often required. As a means of managing all the required state information, application developers often implement ad-hoc state machine programming constructs within the application.