CAF: Call Legs Resync

Call Legs Resynchronization

Since the Toolpack framework has been designed for HA (High_Availability_Overview), it's mandatory that an application that manage calls through CAF_Call_interface is able to deal with call legs re-synchronization.

The current page contains an overview of how re-synchronization works. For more details, please refer to the following page:

CAF:_Working_With_Caf_Call_Legs#Re-synchronizing_with_toolpack_engine

Situations where call leg resynchronization is required

Call legs re-synchronization is required whenever the CAF application looses communication with toolpack_engine:

• The CAF application was restarted
• The toolpack_engine was restarted
• Network connection between CAF application and toolpack_engine was momentarily down

General principles of call legs re-sync

Toolpack Engine

The toolpack_engine application, when restarted, will re-build it's call leg contexts by querying information on the TMedia Units.

• Transient calls (not yet answered) will be dropped
• Terminating calls will be dropped
• Active (answered) calls will be re-build like they were before toolpack_engine was restarted

CAF application

The call control application based on the CAF_Call_interface API will re-build it's call leg contexts by getting information from toolpack_engine.

All active (answered) calls will be re-synchronized from toolpack_engine.

• Calls already known by the application will remain valid
• Calls unknown by the application will be re-constructed (or refused): OnCallLegSync, OnLinkSync
• Calls known by the application, but no more present in toolpack_engine are terminated: OnCallLegTerminated

Example scenarios

In all the scenarios below, let's consider the following situation:

In this situation, the CAF application was restarted (on purpose, or after a crash). It does a cold start up, without any call leg contexts.

For more information...

The current page contains an overview of how re-synchronization works. For more details, please refer to the following page:

CAF:_Working_With_Caf_Call_Legs#Re-synchronizing_with_toolpack_engine