RX_OP_TX
RX_OP_TX(0, 0, 1) /* ACKs both */
RX_OP_TX(0, 0, 2) /* ACKs all */
RX_OP_TX(0, 0, QUIC_PN_INVALID)
RX_OP_TX(0, 1, 5)
RX_OP_TX(0, 2, 10)
RX_OP_TX(0, 0, 1) /* ACKs all */