Dialogic 6.2 manual FXS Ground Start, November 296

Ground Start Signaling

FXS Ground Start

To configure a Brooktrout module for FXS ground start signaling, the host must issue an L4L3mENABLE_CAS with an IISDN_ ROBBED_BIT_DATA structure that contains the following settings:

„in_trunk_type = IISDNtt5ESS_GDSTART

„out_trunk_type = IISDNtt5ESS_GDSTART

„max_incoming_digit_count = 0 (no digits collected)

„timed_answer_supervision = 1 (timer expiration indicates far end answer)

„fgb_fgd_mode = 0 (not used)

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

Incoming Call Processing

During an incoming call, the host receives an L3L4mPRE_SEIZE message if send_preseize_event = 1 in the IISDN_ROBBED_BIT_ DATA structure. This message is sent when the module detects an incoming seizure. No digits are collected in FXS ground start mode; to answer the call, the host must issue an L4L3mCONNECT_ REQUEST message.

Figure 35 shows how a Brooktrout module processes an incoming call received over an FXS ground start trunk.

November 2009 296