Dialogic 6.2 Manuale Utente

Making Two-Channel Call Transfers (Tromboning)

November 2009

191

In the typical two way call transfer application, the application 

detects an incoming call and answers the call. The application then 

performs voice playback and voice recognition functions as needed, 

responding to the caller's spoken utterances. For example, a caller 

might speak someone's name and the application then accesses that 

person's phone number. The application then makes an outbound 

call on another channel by dialing that person's phone number. 

When the person answers the call, the application connects the two 

parties together and monitors both resources to provide additional 

functionality. 

To create the two-channel call transfer and perform the required 

additional functionality, the application must connect various 

hardware resources. These resources are network timeslots for a 

T1/E1 phone line or channels. Each resource has an input slot and 

an output slot. When connecting two resources together, one 

resource must be defined as the source and the other resource 

defined as the destination. The application should define the 

connection type between the two resources as “transmit” because the 

Brooktrout hardware maintains connections as transmits. 

To understand the basic connections that exist between a channel 

and a network timeslot, see 

. These connections are defined 

in a Brooktrout configuration file called callctrl.cfg. The connection 

lines represent both signaling and voice data. When making a 

two-channel call transfer, the application should modify only the 

voice data connections.