In current version, user has to explicitly call Packet#calc before sending a packet to send a well-formed packet. This is not done automatically to allow user to send malformed packets on wire.
But, in real life, users want to send well-formed packet more often than bad-formed ones.
In future v3.0.0 of PacketGen, Packet#calc will be automatically called, unless user explicitly forbids it.
In current version, user has to explicitly call Packet#calc before sending a packet to send a well-formed packet. This is not done automatically to allow user to send malformed packets on wire.
But, in real life, users want to send well-formed packet more often than bad-formed ones.
In future v3.0.0 of PacketGen, Packet#calc will be automatically called, unless user explicitly forbids it.