packet-beta
    title TCP header
    0-15: "Source Port"
    16-31: "Destination Port"
    32-63: "Sequence Number"
    64-95: "Acknowledgement Number"
    96-99: "Data Offset"
    100-105: "Reserved"
    106: "URG"
    107: "ACK"
    108: "PSH"
    109: "RST"
    110: "SYN"
    111: "FIN"
    112-127: "Window"
