The Delivered_Event is part of the Event Data Feed Interface, and the
Request_Instruction is part of the Service Control Interface. These two
interfaces are mutually exclusive. An IVR can't use these two interface
at any same time. You can implement both, but can only use one of the
two at any given time.

If a call is routed to the IVR by ICM from another Peripheral, how does
the IVR identify the call to the ICM if it can't use the Trunk and Trunk
Group? The answer is that the ICM doesn't use the Trunk and Trunk Group
to identify the call. The only thing the Trunk and Trunk Group is used
for is for the ICM to keep track of the trunk utilization to use in
routing. It uses the Correlation ID if delivered by the Network to
identify the call. Otherwise the ICM uses the DNIS in the Translation
Route.

The Event Data Feed Interface and Service Control Interface rely
heavily on the Initialization of the interface with the a snapshot of
the current state of the IVR (i.e. Trunks, TrunkGroups, Services,
etc...). When the connection with the IVR first comes up, the IVR can
optionally send an initial snapshot of the Trunks, TrunkGroups, and
Services that are configured. From that point on, as calls arrive and
are cleared at the IVR, the IVR sends call event messages (ie.
Delivered, Cleared, etc... in the case of the Event Data Feed or the
New_Call or Request_Instruction messages in the case of the SCI), the
ICM will then keep track of the trunk utilization, and can then route
calls to the IVR accordingly.

If you are not routing calls to the IVR from another Peripheral using
trunk utilization within the ICM, then you don't need to configure
trunks or send the Trunk/Trunk Group initialization. It is optional. If
you just send "0" for the Trunk and Trunk Group fields in the
Delivered_Event or NEW_CALL message it should work just fine. Our
Custom Engineering team used the Service Control Interface (SCI) and
sent the NEW_CALL message to the ICM to request a route to an agent
skill group. They sent "0" in the Trunk, TrunkGroup, and ServiceID
fields, and it worked fine since they weren't routing to the "IVR".

Also, If you don't use Trunk and Trunk Group information, you won't
have any Trunk Group Real Time database records.

Hope this helps.