NEXT_SEQID
if (dp_msgp->txnum != NEXT_SEQID(dps->last_rx_seqid)) {
dps->last_tx_seqid = NEXT_SEQID(dps->last_tx_seqid);
#define IS_NEXT_SEQID(a, b) ((b) == NEXT_SEQID(a))