By default, the Diva TTY interface operates in "channel pool" mode. It presents the available Diva Media Boards as one board to the user application. This board owns the channels provided by the real Diva Media Boards.
This feature hides the call distribution details from the application and allows creation of servers such as RAS.
You can use the AT+iQ command to control this behavior and to bind specific Diva TTY interfaces to specific Diva Media Boards. See AT-Command Set for more information.
Note: It is possible to bind specific Diva TTY interfaces to specific Diva Media Boards. But it is not possible to bind specific Diva TTY interfaces to specific B-channel numbers due to the fact that B-channel resources are automatically assigned by the active signaling protocol.
Incoming calls are handled in the following sequence of operations:
The Diva Media Board receives a call.
The Diva Media Board uses the active signaling protocol to select the B-channel that will be used for this call.
The Diva Media Board delivers the call to the Diva TTY driver.
The Diva TTY driver delivers the call to the first application that matches the call type and is ready to receive incoming calls (ATS). See AT-Command Set for more information on the ATS commands.
Outgoing calls are handled in the following sequence of operations:
The user application issues a call on an arbitrary Diva TTY interface.
The Diva TTY interface transfers the call request to the first Diva Media Board that is able to handle this call type and owns free B-channel resources.
The Diva Media Board uses the active signaling protocol to select the B-channel that will be used for this call.