Ground Start Signaling
November 2009 297
Figure 35. FXS Ground Start – Incoming Call Timing Diagram
IISDN SMI MESSAGES: L4L3mALERTING_REQUEST or L4L3mPROGRESS_REQUEST L4L3mCONNECT_REQUEST
L3L4mPRE_SEIZE L3L4mSETUP_IND
IISDN TIMERS:
hooktimer_onhook_rls
modified_in_rls_time
r
hooktimer_onhk_mod_in_rls
first_indigit_time
r
dptimer_immed_dela
y
RECEIVE HOOKSWITCH, FXO:
A Bi
t
B Bit (ignored)
TRANSMIT HOOK SWITCH, FXS: NOTE: No digits are collected on the near end in this mode.
A Bi
t
B Bi
t
NOTE: This diagram is designed to give the reader a general understandi ng of the sequence of events for this robbed
bit protocol over time. The timers and spacing on t his graph are not proportional to the actual events that occur.
Revised 10-Nov-98
Revision 1.3
RECEIVED BITS, TRANSMITTED Revised