Dialogic 6.2 manual FXO Loop Start, November 303

Loop Start Signaling

FXO Loop Start

To configure a Brooktrout module for FXO loop start signaling, the host must issue an L4L3mENABLE_CAS with an IISDN_ROBBED_ BIT_DATA structure that contains the following settings:

„send_glare_err_event = 0 (not used for loop start)

„in_trunk_type = IISDNttFXO_LPSTART

„out_trunk_type = IISDNttFXO_LPSTART

„timed_answer_supervision = 0 (answer supervision required)

„fgb_fgd_mode = 0 (not used)

The remaining settings are described in the context of incoming and outgoing calls in the subsections that follow.

Note: The FXO end of a loop start connection uses the same A and B bit values for both idle and connected states. Because of this, the Brooktrout module cannot detect when the FXO end goes on hook. To idle the channel, the host must detect the presence of a busy/reorder tone coming from the FXO end and issue an L4L3mCLEAR_REQUEST to disconnect the call. To ensure the FXO end returns to an idle state, the host must also reset the channel by issuing an L4L3mDISABLE_CAS immediately followed by an L4L3mENABLE_CAS in order to make another call.

November 2009 303