Study and improvement of IP datagram reassembly algorithms

One of an important mechanism of IP is fragmentation and reassembly.When IP packet is fragmented,the IP layer at the receiving host must accumulate these fragments until enough have arrived to completely reconstitute the original datagram.By studying and contrasting the IP datagram fragment algorithms described by RFC791 and RFC815,the deficiencies are analyzed.The fragment processing algorithm described by RFC815 is improved,and the security is also enhanced.