Hi kavle,
Send to VRU node passes the call flow from ICM to CVP components to start IVR activities. When your ICM script executes the Send to VRU node, the system activates the voice browser (VVB) - all this is described in the document Bill sent to you. When the VVB is activated and ready, the call flow is returned back to the ICM and goes typically to Run Ext Script node, which starts a VXML Studio app on the VXML server or executes any microapps.
The reason why you do not see any difference when you removed the Send to VRU node from your ICM script is that the Run Ext Script node contains built-in Send to VRU function in itself. In the monitor it seems that the ICM script just performs one Run Ext Script node, but in fact it executes two actions - Send to VRU first followed by Run Ext Script.
Why do we still use Send to VRU separately in the ICM scripts? The answer is very simple - for troubleshooting reason. If you use just Run Ext Script and have problems with its execution (your call goes to failure connector of this node), it is hard to understand, why it happens. You don't know whether the VVB is not activated (Send to VRU function) or VXML App\Microapp (Run Ext Script) fails. However, if you use both Send to VRU node AND Run Ext Script node in the script, it is absolutely clear where the problem is. If you flows goes to failure connector of the Send to VRU node - then you have to focus on VVB activation and investigate this part of the call flow. But if Send to VRU completed successfully, the call goes next to Run Ext Script node and fails there it means that the VVB is ok and activated. Then check the settings related VXML App, microapp and so on.
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