sctp_send_hb
sctp_send_hb(stcb, 1, net);
int sctp_send_hb(struct sctp_tcb *, int, struct sctp_nets *);
if (sctp_send_hb(stcb, 0, NULL) < 0) {
if (sctp_send_hb(stcb, 0, NULL) == 0)
sctp_send_hb(stcb, 1, net);
sctp_send_hb(stcb, 1, net);