static void dissect_RTI_CRC(tvbuff_t *tvb, packet_info *pinfo, gint offset, guint8 flags,
        const guint encoding, gint octets_to_next_header,proto_tree *tree) {
   /*
    * 0...2...........7...............15.............23...............31
    * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    * |   RTI_CRC     |X|X|X|X|X|X|X|E|      octetsToNextHeader       |
    * +---------------+---------------+---------------+---------------+
    * |        RTPS Message length (without the 20 bytes header)      |
    * +---------------+---------------+---------------+---------------+
    * |                             CRC32                             |
    * +---------------+---------------+---------------+---------------+
      Total 12 bytes */
   proto_item *octet_item;

   proto_tree_add_bitmask_value(tree, tvb, offset + 1, hf_rtps_sm_flags, ett_rtps_flags, RTI_CRC_FLAGS, flags);

   octet_item = proto_tree_add_item(tree, hf_rtps_sm_octets_to_next_header, tvb,
                         offset + 2, 2, encoding);

   if (octets_to_next_header != 8) {
     expert_add_info_format(pinfo, octet_item, &ei_rtps_sm_octets_to_next_header_error, "(Error: should be == 8)");
     return;
   }

   offset += 4;
   proto_tree_add_item(tree, hf_rtps_sm_rti_crc_number, tvb, offset, 4, encoding);

   offset += 4;
      proto_tree_add_item(tree, hf_rtps_sm_rti_crc_result, tvb, offset, 4, ENC_BIG_ENDIAN);
}
static void dissect_RTI_CRC(tvbuff_t *tvb, packet_info *pinfo, gint offset, guint8 flags,
        const guint encoding, gint octets_to_next_header,proto_tree *tree) {
    
   proto_item *octet_item;

   proto_tree_add_bitmask_value(tree, tvb, offset + 1, hf_rtps_sm_flags, ett_rtps_flags, RTI_CRC_FLAGS, flags);

   octet_item = proto_tree_add_item(tree, hf_rtps_sm_octets_to_next_header, tvb,
                         offset + 2, 2, encoding);

   if (octets_to_next_header != 8) {
     expert_add_info_format(pinfo, octet_item, &ei_rtps_sm_octets_to_next_header_error, "(Error: should be == 8)");
     return;
   }

   offset += 4;
   proto_tree_add_item(tree, hf_rtps_sm_rti_crc_number, tvb, offset, 4, encoding);

   offset += 4;
      proto_tree_add_item(tree, hf_rtps_sm_rti_crc_result, tvb, offset, 4, ENC_BIG_ENDIAN);
}