The Implementation And Improvement Of A Dual Stack Lite Tunnel

With the rapid development of the Internet, IPv4 addresses run out much faster than originally designed.Nowadays the widely used network standard is IPv4,the network developing is so fast and the demand for IP address is so much that we didn't expected when the protocol is designed, IPv4 addresses has been used up since February 2th, 2011.On the one hand, there isn't much available IPv4 address. On the other hand, as the Internet and the Internet of things developing, more and more things should be linked into the Internet, which means more IPv4 addresses should be taken. In such a background,IPv6 arises as the time requires. However, the gradual process of IPv6 goes slow for varieties of reasons,therefore, a transition plan is needed to support the upgrade from IPv4 to IPv6. DS-Lite(lightweight double protocol stack) is such a transitional plan to make IPv4 continue and furtherance the completeness of IPv6.DS-Lite combinations of two mature technology——the Tunnel and the NAT,making it a easy way of transition. The 4 over 6 tunnel packs and depacks the message,which adds a IPv6 beginning in front of the message and send it to the convergence point on the other side through IPv6 network. The convergence point on the other side of the tunnel receives the packed message and unpack it. Then can get the original IPv4 message.NAT mainly finishes the change of network addresses. This can solve the problem of lacking network addresses and make more reuse of the network addresses. It also protects the personal network in some ways on the other hand.By finishing the mainly design of the DS-Lite system framework and worked out the purpose of designing and the plan through comparing some transition plans and documents about analysis of tunnel technology and NAT, did the relevant test after its bringing out. Also, it found out some serious defects and related researches have been made to find out solutions.