#define R2_STATUS_FORMAT "[%d/%8X/%-14s/%-13s]"

static void mf_tone_on_event(uc_t *uc, int tone_id);
static void mf_tone_off_event(uc_t *uc);
static void abcd_signaling_event(uc_t *uc, int ch);

static int set_abcd_signal(uc_t *uc, int ch, uint8_t abcd);
static int set_mf_signal(uc_t *uc, int ch, int forward_signal);

static void select_active_rxtx(uc_t *uc, int which);
static void t1_expired(uc_t *uc, void *data);
static void t1a_expired(uc_t *uc, void *data);
static void t1b_expired(uc_t *uc, void *data);
static void t2_expired(uc_t *uc, void *data);
static void t3_expired(uc_t *uc, void *data);
static void seize_ack_wait_expired(uc_t *uc, void *data);
static void release_guard_expired(uc_t *uc, void *data);
static void far_unblocking_expired(uc_t *uc, void *data);
static void local_unblocking_expired(uc_t *uc, void *data);
static void answer_guard_expired(uc_t *uc, void *data);
static void clear_back_persistence_expired(uc_t *uc, void *data);
static void billing_pulse_expired(uc_t *uc, void *data);
static int send_calling_party_category_request(uc_t *uc);

static int variant_element(const char **variant, int which)