Cisco Cisco Unified Customer Voice Portal 10.5(1)

This section examines initial call transfer from the CVP, specifically, how the NAM/ICM, CVP, 
Gatekeeper, and Voice Gateways work together to perform H.323-based call transfer.

Subsequent call transfers (such as agent initiated transfers), being similar to the examples described 
below, are not discussed separately. One important difference, however, is that the 
Call.NetworkTransferEnabled variable must be set to 1 in each script that contains network transfer 
instructions.

When the CVP receives the ICM/IVR message from the NAM/ICM, the CVP examines the initial two 
characters in the Label field to determine the transfer mode. If the initial four characters are DTMF, then 
the CVP will use outpulse transfer mode to transfer the call. Outpulse transfer mode instructs the CVP 
to send the transfer information to the originating Voice Gateway, which will then outpulse the 
information to the ingress leg of the call. This initiates the call transfer in an external telephony network.

When the outpulse mode is used, the first two characters of the transfer information may be an attention 
sequence for the telephony network, such as *8.

The CVP initiates the outpulse transfer by stripping off the DTMF characters from the Label field, and 
sending the remaining transfer information to the originating Voice Gateway, using the call’s existing 
H.245 control session. (The transfer information is passed in an H.245 userInputIndication message.)

With outpulse transfer mode, the CVP communicates with the incoming Gateway, which already has an 
H.245 control session for that particular call. Therefore, the CVP does not need to perform a lookup in 
its assigned H.323 Gatekeeper, and can proceed directly with the transfer. 

A Voice Gateway can provide access to a Time-Division Multiplexing (TDM) switching network; or it 
can be connected to an ACD, PBX, or to one or more phones. 

In outpulse transfer mode, the originating Gateway receives transfer information from the CVP for a 
particular call through H.245 messaging. The Gateway converts the transfer information to DTMF 
signals and outpulses them to the call’s ingress TDM leg. From that point, the call transfer becomes the 
responsibility of equipment on the TDM network.

Two things must happen for the Gateway to support relay of the H.245 information:

First, the Gateway must have been configured to support H.245 relay for that particular call. This is 
done by adding an H245 relay command to the dial-peers that route inbound calls to the CVP. The 
H245 relay command provides the option of choosing either the signal or alphanumeric methods 
of relay. The signal option is recommended for use with the CVP. 

Second, the CVP must indicate support for a compatible method of H245 relay during the H.245 
capabilities exchange with the Gateway.