Service Control Interface usage overview

The SCI enables an ICM Script to determine the call-handling steps that will be performed by a VRU and to perform the requested action. The SCI must be initialized before it is used. When initialized, the interface allows an ICM Script to control calls that arrive at a VRU. The calls might have been pre-routed to the VRU by the ICM, or routed to the VRU by other methods. In either condition, a Service Control dialog must be started by the VRU for each call that the ICM controls. The ICM Script starts the Service Control transactions to the VRU by using a newly defined SCI message set. The VRU processes request messages and performs the requested action.

Acknowledgment messages are sent by the VRU to indicate that a request has been completed. The Service Control dialog ends when one of the following conditions occurs:
  • The ICM Script controlling the call has run to completion.
  • The call ends.
  • An unrecoverable error occurs.
The effect of this new method of call handling is that the ICM, which has knowledge of the real time call load on a whole network, can instruct a VRU to perform a specific task, then cancel that request at any point. For example, this new method can be used to perform VRU queuing where a VRU is instructed to play music to a caller while the ICM waits for a suitable agent to become available. When an agent becomes available, the ICM can instruct the VRU to stop playing music and transfer the call to the agent. In addition to the request or response call control transactions, the VRU provides event reports that indicate changes in call state. A Service Control dialog can be defined as a conversation that is between the VRU and the ICM and consists of one or more related call-control transactions. A Service Control dialog provides the context under which the transactions are performed. When a Service Control dialog has been made, the ICM controls the VRU call handling with an ICM Script. When the ICM has taken control of a call, the router keeps call control until the Service Control dialog is ended.