DCCPO_TIMESTAMP_ECHO = 42,
        DCCPO_ELAPSED_TIME = 43,
        DCCPO_MAX = 45,
-       DCCPO_MIN_CCID_SPECIFIC = 128,
-       DCCPO_MAX_CCID_SPECIFIC = 255,
+       DCCPO_MIN_RX_CCID_SPECIFIC = 128,       /* from sender to receiver */
+       DCCPO_MAX_RX_CCID_SPECIFIC = 191,
+       DCCPO_MIN_TX_CCID_SPECIFIC = 192,       /* from receiver to sender */
+       DCCPO_MAX_TX_CCID_SPECIFIC = 255,
 };
 /* maximum size of a single TLV-encoded DCCP option (sans type/len bytes) */
 #define DCCP_SINGLE_OPT_MAXLEN 253
 
                }
 
                /*
-                * CCID-Specific Options (from RFC 4340, sec. 10.3):
-                *
-                * Option numbers 128 through 191 are for options sent from the
-                * HC-Sender to the HC-Receiver; option numbers 192 through 255
-                * are for options sent from the HC-Receiver to the HC-Sender.
-                *
                 * CCID-specific options are ignored during connection setup, as
                 * negotiation may still be in progress (see RFC 4340, 10.3).
                 * The same applies to Ack Vectors, as these depend on the CCID.
-                *
                 */
-               if (dreq != NULL && (opt >= 128 ||
+               if (dreq != NULL && (opt >= DCCPO_MIN_RX_CCID_SPECIFIC ||
                    opt == DCCPO_ACK_VECTOR_0 || opt == DCCPO_ACK_VECTOR_1))
                        goto ignore_option;
 
                        dccp_pr_debug("%s rx opt: ELAPSED_TIME=%d\n",
                                      dccp_role(sk), elapsed_time);
                        break;
-               case 128 ... 191:
+               case DCCPO_MIN_RX_CCID_SPECIFIC ... DCCPO_MAX_RX_CCID_SPECIFIC:
                        if (ccid_hc_rx_parse_options(dp->dccps_hc_rx_ccid, sk,
                                                     pkt_type, opt, value, len))
                                goto out_invalid_option;
                        break;
-               case 192 ... 255:
+               case DCCPO_MIN_TX_CCID_SPECIFIC ... DCCPO_MAX_TX_CCID_SPECIFIC:
                        if (ccid_hc_tx_parse_options(dp->dccps_hc_tx_ccid, sk,
                                                     pkt_type, opt, value, len))
                                goto out_invalid_option;