Encoding And Decoding Of Asn.1-based Intelligent Network Technology Research,

This study presents the work of designing and implementing of the Intelligent Network(IN) encoding/decoding technology based on ASN.1.First,there are briefly guidelines for mainly background knowledges about ASN.1 and IN.We expatiate on the definition,feature and the application of ASN.1,and have guidelines for the conception,architecture and protocal of IN.Subsequently,we have studies about the standards of ASN.1 syntax and encoding rules.We describe the base data types in ASN.1 and the rules for combination these base data types to compound data types.There also is a deltailed description of encoding rules which can be used for values defined by ASN.1.Then,based on the analysis about general encoding/decoding technologies and requirements of this project,our algorithm about ASN.1 encoding/decoding is put forward.In this algorithm,based on ASN.1 syntax and base encoding rules,we define the rules of format-string.The descriptions of application protocal can be translated to format-string according to these rules.Based on format-strings and binary tree,the method of null-inserting-encoding has been used to finish INAP messages encoding. For decoding,the method to be used is parsing-assignment-getting.And then,we implement this algorithm module by using c++ language.There are three classes in the module which has been implemented,datahandle,datahandle_s and datahandle_r.The interface of this module is simple,so you can use it easily.Finally,based on the ASN.1 encoding/decoding module which has been implemented,we implement an INAP encoding/decoding example program.Depending on the INAP criterion messages,we have some experiments about functions of the encoding/decoding module.In these experiments,we choose two INAP operations, Initial DP and Connect,for decoding and encoding test.Test results show that,the designed module not only can correctly,rapidly and automatically finish its functions, but also has features of high effiency.