Dialogic 6.2 Manuale Utente

Immediate Start/Fixed Pause Signaling

November 2009

285

Immediate Start signaling applies to incoming calls only; Fixed 

Pause signaling applies to outgoing calls only. Since these signaling 

types functionally complement each other, they are handled together 

by Brooktrout modules. The exact protocol to be used for a call is 

automatically selected depending on whether an incoming or 

outgoing call is being handled. To avoid confusion, the symbolic 

constants used to select these two protocols, IISDNttIMMEDIATE_

DIAL and IISDNttFIXED_PAUSE, are set to the same value.

To configure a Brooktrout module for immediate start and fixed 

pause mode 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)

„

in_trunk_type = IISDNttIMMEDIATE_DIAL or 

IISDNttFIXED_PAUSE

„

out_trunk_type = IISDNttIMMEDIATE_DIAL or 

IISDNttFIXED_PAUSE

„

fgb_fgd_mode = 0 (not used)

The remaining settings are described in the context of incoming and 

outgoing calls in the subsections that follow.

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 (off hook). The module then collects dial pulse 

digits from the network; the maximum number of digits the module 

expects to receive must be specified in the max_incoming_digit_

count field. The digits are reported to the host in an L3L4mSETUP_

IND message. To answer the call, the host must issue an 

L4L3mCONNECT_REQUEST message.

 shows how a Brooktrout module processes an incoming 

call received over an immediate start trunk.