ASN.1及其PER编码在视频会议系统中的应用研究

抽象语法表符号1（ASN.1）在多媒体网络通信中起着非常重要的作用.ASN.1被用于描述基于H.323协议的视频会议系统的信令消息.介绍了ASN.1的基本概念、数据类型和数据表示方法,详细分析了ASN.1在网络传输编码中使用的分组编码规则（PER）,并结合H.323协议中所常用的数据类型举例说明了其信令消息的PER编码过程.     

基于BER的ASN．1编解码原理与设计实现

本文介绍了ASN．1和BER基本编码规则，分析了7号信令协议栈的TCAP层消息结构和ASN．1之间的关系，详细介绍了应用于信令中继系统中的ASN．1编解码模块的设计和实现。     

网络电话中ASN.1编解码器的实现研究

简要介绍了抽象语法标记语言ASN.1,以及BER和PER编码规则,阐述了网络电话中H.323协议栈的ASN.1编解码器的设计与实现。     

XML技术在网络管理中的应用

在基于SNMP的网络管理中，MIB数据是使用ASN．1描述BER编码的，可读性不强。而XML因其良好的自描述性和结构化特征，非常适合表示MIB数据。讨论了用XML表示MIB数据的方法，使用此方法，实现了一个SNMP与XML之间的转换系统。     

基于面向对象方法的ASN.1编解码的设计与实现

随着计算机和通信技术的发展，ASN．1作为多种协议在表示层的抽象语法记法，它的作用在多媒体通信，协议测试等领域都非常重要。该文采用面向对象的设计方法实现了ASN．1标准X690，同时，通过比较各种编码规则的特点，在BER编解码实现的基础上，给出CER、DER及PER编码的实现方案，据此实现的ASN．1编解码对外提供了一致的接口，具有很好的通用性。     

XML在网管协议中的应用

提出了一种新的把XML和传统网络管理相结合的方法,它可在不改变传统网管协议的基础上,采用XER编码传输用ASN.1描述的网管协议报文数据,这样报文数据能够通过Web进行传输,报文信息内容的提取和共享变得相当容易.     

H.323协议栈中ASN.1模块的设计与实现

对ASN．1及PER编码规则作了简要介绍，接着提出了一种ASN．1编解码模块在H．323协议栈中的设计与实现的方案。     

基于BER的ASN.1语法编译器及编解码器实现与应用

介绍了ASN.1标记语言和BER基本编码规则。结合其在移动通信国际漫游话单中的应用场景,详细介绍了应用于移动通信国际漫游话单处理系统中的ASN.1语法编译器和BER编解码模块的设计与实现。     

数据编码、解码的Java实现

描述了基于SNMP协议的常用数据类型的种类及特性,按照ASN．1语法对MIB（管理信息库）中被管对象编码、解码的基本规则,用Java语言给予了实现。     

基于MMS的ACSI信息解码模块分析与设计

针对ACSI信息的解码问题,设计了一种基于MMS报文的解码模块。分析了IEC61850标准和制造报文规范MMS之问的模型映射关系,给出了抽象通信服务接口ACSI和制造报文规范MMS之间的服务映射规则。在分析抽象语法标记ASN．1的BER编码规则基础上,分析了MMS报文的解码过程,并且将MMS协议数据单元PDU的抽象语法描述转换为C语言中的特定结构体,提出了基于MMS的ACSI信息解码模块的设计方法,并基于上述方法设计了解码模块的C语言程序。实验结果表明,本解码模块能够正确实现MMS报文的解码。     

The design and implementation of an ASN.1-C compiler

Abstract syntax notation one (ASN.1) has been widely used in international standard specification: its transfer-syntax, the basic encoding rules (BER), is used as the external data representation. A BER implementation called the ED library is presented. The ED library includes a number of encoding and decoding routines that may be used as primitive functions to compose encoders and decoders for arbitrarily complicated ASN.1 data types. Based on the ED library an ASN.1-C compiler, called CASN1, is designed and implemented to free the protocol implementers from the arduous work of translating protocol-defined data-types and constructing their encoders and decoders. Given an ASN.1 protocol specification, CASN1 automatically translates the input ASN.1 modules into C and generates the BER encoders and decoders for the protocol defined data-types. The CASN1 design principles, user interface, and some example applications are discussed. The performance of the ED library and generated CASN1 code is also measured and discussed     

EASE : A Software Environment for Automatic Implementation of Application Protocol

At present, ASN.1, and encoding and decoding rules, are not supported by Estelle. Estelle only specifies dynamic behaviours of protocols; and protocol data units of application layer protocol are specified in ASN.1. Hence, two standardized languages are required to specify an application protocol. In addition, Estelle and ASN.1 tools have been developed independently and do not support each other. As a result of these difficulties, the implementation of an application protocol is time consuming. To address this difficulty, we have proposed an approach which unified ASN.1 and Estelle specifications, and showed that the automatic implementation of an application protocol can be readily achieved by providing a software environment which supports this unified specification. This paper describes the detail of this software environment called EASE, and the results of using it to develop an implementation of the ISO FTAM protocol.     

Integrated Estelle and ASN.1 specification approach to automatic implementation of application protocol

Estelle currently does not support ASN.1 and encoding and decoding rules. Tools developed for Estelle and ASN.1 have been developed independently of each other. As such, ASN.1 tools do not support Estelle and vice versa. At present, due to these two separate specifications, implementation is time consuming. It is imperative to find a way for ASN.1 and Estelle specifications to be efficiently integrated to facilitate fully automatic implementation. This paper describes how Estelle and ASN.1 can be integrated to give a unified specification which can then be fed into a software environment to produce a truly automatic implementation of an application protocol, including encoding and decoding of protocol data units, when application layer protocols are specified in Estelle and in ASN.1. The integration approach is based on the powerful programming concept, Data Abstraction. The software that implements this integrated specification approach to automatic implementation of application protocol is called EASE (Estelle and ASN.1 Software Environment). To demonstrate the viability of the approach, the unified specification of the ISO ACSE and Presentation protocols are also presented.     

嵌入式VOIP系统中ASN.1编解码器的实现

抽象语法描述ASN.1已经被广泛地运用于协议通信。在VOIP应用中,同样也要用到ASN.1编解码。但是由于H.323协议栈本身的asn描述文件较大,使得传统的ASN.1编解码方案在资源有限的嵌入式系统中并不适用。文章在实际开发项目的基础上,提出了一个适用于嵌入式系统的解决方案。