| In the past few decades,the Internet which based on the TCP/IP network architecture has achieved unprecedented success.However,as new application scenarios appear constantly,and the rapid increase of the demand for multimedia information content,the Internet is experiencing severe tests.So,how to design a new Internet architecture who can satisfy the need of new scenarios and new demands,this problem has become one of the important research topic in the field of computer network research.A new network architecture which is centered on information content,proposed in recent years,is gradually receiving more and more attention from the researchers.Named Data Networking(NDN)is a representative of the new network architecture,which has realized rapid development,and has achieved a series of important theoretical and application results.However,how to further improve the performance of NDN's forwarding module is still one of an important and difficult research.Forwarding Information Base(FIB)is a very crucial component of NDN's forwarding module.A FIB in NDN not only needs to be constructed high-efficiently,but also supports fast dynamic name lookup.The dynamic means the FIB should support insert,update and delete operations when name lookup executing.To solve these problems,in this paper,we consider these from the perspectives of dynamic name lookup,efficiency of the construction of FIB and saving memory overhead,and we propose an efficient dynamic name lookup method based on adaptive radix tree.This method not only can use NDN's naming rules and characteristics of radix tree's data structure to achieve dynamic name lookup and fast FIB construction,at the same time also can use the characteristics of the node size which can be adaptively adjusted,to sharply reduce the memory overhead.Using this new method to design a FIB,we call it as Dynamic Self-Index FIB(DSIF).In order to make the adaptive radix tree is more in line with the longest name prefix matching principle,we also improve it,not only to adjust the types of the inner node and leaf node,but also to modify the insert and lookup operations correspondingly.It allows the name path without decomposition for multistage name prefix match for lookuping several times.In this paper,just a single lookup operation can quickly obtain the correct forwarding port.In addition,in order to further improve the efficiency of dynamic name lookup and reduce the memory overhead of FIB,we introduce two kinds of existing space compression technology,and the Path Compression technology can reduce the number of inner nodes,and Lazy Expansion technology can save the memory overhead of long name prefix.At the same time,the two technologies also play a role for dynamic name lookup efficiency.The final experimental evaluation shows that DSIF which based on our method can support efficient dynamic name lookup,also can guarantee the speed of the construction of FIB,and save the memory cost of newly built FIB index to a certain extent,and can meet the demand of NDN's fowarding module for high-performance FIB. |
