FTDM_CAUSE_PROTOCOL_ERROR 322 src/ftmod/ftmod_r2/ftmod_r2.c case FTDM_CAUSE_PROTOCOL_ERROR: FTDM_CAUSE_PROTOCOL_ERROR 870 src/ftmod/ftmod_r2/ftmod_r2.c ftdmchan->caller_data.hangup_cause = FTDM_CAUSE_PROTOCOL_ERROR;