#if !defined(MEM_ETH_DEST)

#define MEM_ETH_DEST    packet_header+0
#define MEM_ETH_SRC     MEM_ETH_DEST+6
#define MEM_ETH_PT      MEM_ETH_SRC+6

#define MEM_IPH         MEM_ETH_PT+2
#define MEM_IP_HVTOS    MEM_IPH+0
#define MEM_IP_LEN      MEM_IPH+2
#define MEM_IP_ID       MEM_IPH+4
#define MEM_IP_FFO      MEM_IPH+6
#define MEM_IP_TTLP     MEM_IPH+8
#define MEM_IP_CHKSUM   MEM_IPH+10
#define MEM_IP_SRCADDR  MEM_IPH+12
#define MEM_IP_DSTADDR  MEM_IPH+16
#define MEM_IPD         MEM_IPH+20

#define MEM_UDP_HEADER  MEM_IPD+0
#define MEM_UDP_SP      MEM_UDP_HEADER+0
#define MEM_UDP_DP      MEM_UDP_HEADER+2
#define MEM_UDP_LEN     MEM_UDP_HEADER+4
#define MEM_UDP_CHKSUM  MEM_UDP_HEADER+6
#define MEM_UDP_DATA    MEM_UDP_HEADER+8
    
#endif