Dialogic 6.2 Manuale Utente

Ground Start Signaling

November 2009

298

If send_glare_err_event = 0 in the IISDN_ROBBED_BIT_DATA 

structure, the host receives an L3L4mERROR message containing 

the value L3L4errGLARE if the outgoing call attempt fails due to 

glare. Glare occurs when the module attempts to make an outgoing 

call on a channel at the same time an incoming call arrives on the 

channel. The call attempt fails because the network always wins 

channel contention.

During an outgoing call, the host receives an L3L4mPROGRESS in 

response to the L4L3mCALL_REQUEST to start the call. The 

module starts the fixed pause timer when it detects tip ground at the 

far end (FXO end). When the timer expires, the host receives an 

L3L4mSEIZE_COMP message if send_seize_comp_event = 1 in the 

IISDN_ROBBED_BIT_DATA structure.

FXS ground start supports transmitting digits other than dial pulse 

digits. If called_party_digits = 0 in the L4L3mCALL_REQUEST that 

started the call, the module waits in outdialing state indefinitely. 

During that time, another device connected to the Brooktrout 

module over the TDM bus (such as a digital tone generator) is used 

to outpulse digits to the network.

After the digits are transmitted, the module waits for an answer 

timer to expire (if timed_answer_supervision = 1). When the timer 

expires, the host receives an L3L4mCONNECT indicating the call is 

connected.

 shows how the module makes an outgoing call over an 

FXS ground start trunk.

For an incoming call teardown, refer to 

; for an outgoing 

call teardown, refer to