On The ISDN Branch Control Technology Based On Linux Operating System Research

The Integrated Services Digital Network(ISDN)is a set of international standards for access to all-digital public telecommunication networks,a typical circuit-switched network.It is evolving from a telephone IDN,provides end-to-end digital connectivity.Because ISDN is a fully digital circuit,which can provide stable data services and connection speed,don't have severe channel interference as analog lines.Otherwise,it can offer a lot of digital information services which couldn't be support or difficult to ensure the quality by analog lines.For the current ISDN user network,B channels can only be shunted by hardware and terminal equipments,whichnot only increase the cost of operator,but also requireISDN network-side equipments and shunt devices have matching interfaces,that leaves operator limited options in ISDN network-side equipments.Besides,for some special network-side equipments such as satellite terminals,which can't use shunt devices due to the mismatch of interfaces,lead to the waste of communication resources.In the thesis,a Linux-based ISDN shunt control protocol architecture is proposed to solve the problems above.Under the protocol architecture,B channels are shunted by software instead of hardware or terminal equipment.Firstly,the background and significance of this project,as well as the current research situation and development trend of ISDN are discussed at the beginning of this thesis,it also overviews the weaknesses of implementing ISDN UNI protocol(DSS1)in traditional way.The basic knowledge of ISDN,such as network architecture,application present status and core technology are introduced in the second paragraph.On this basis,the composition of DSS1 shunt control protocol architecture is introduced,which including two parts:protocol for shunt controlling and(DSS1)protocol.protocol for shunt controlling provides B channels shunting,messages monitoring,etc.DSS1 just handles the signaling interaction,build and maintenance of communication connect with ISDN network-side equipments.The whole design and signaling processes of the protocol architecture are described,followed by the introduction of the working principle and detailed process design of its main module.The entire protocol architecture provides a clear modular structure,in order to achieve good inheritance and scalability.Complete call-signaling processes are offered by signaling monitor when there is a call,and the results are analyzed in short.Finally,the summing-up of the thesis is made up,and the expectation of future study of this research is listed.