Research And Implementation Of Megaco Protocol In IMS Network

At present, with the rapid development of mobile internet, and the state’s active promotion for "Internet plus" action, as well as the user’s access to wireless broad band’s speed and demand for anytime and anywhere is increasing, 4G LTE(Long Term Evolution) network construction and deployment is entering the peak. The final solution of LTE voice service is VoLTE which is based on IMS platform. IMS due to support a variety of access and rich multimedia business, it has become the core network standard architecture of the whole IP Era. Currently carriers actively test Vo LTE technology, it is time to deploy commercial VoLTE network, which also lead to the rapid deployment of IMS. A variety of HD voice and video codecs introduction lead more demands for IMS Media Control Protocol(Megaco) and its implementation.When VoLTE networks were being deployed and tested in customer’s lab environment, if the new types of terminals or multimedia-related applications were introduced, the result often requires modifying the Megaco protocol stack extended.But protocol stack modifying usually spend long time, it cannot meet customer demand for rapid iteration release. To solve this problem, this paper studies the use of Megaco protocol in IMS networks, as well as the new implementation of Megaco protocol stack.Lex(Lexical Analyzer) and Yacc(Yet Another Compiler Compiler) are strong lexical analyzer and syntax analyzer generation tools. Using Lex and Yacc can automatically generate a language compiler. Megaco protocol ABNF defines the lexical and syntax, it is actually a language, so the Megaco protocol parser can be generated by using Lex and Yacc.The new stack uses Lex and Yacc to generate Megaco protocol parsing code according to Backus-Naur forms. If you need to support the new Megaco expansion pack, you only need to add its Backus paradigm, Lex and Yacc will automatically generate a new parsing code to generate a convenient extension of the Megaco protocol stack. This will be able to quickly support the deployment of VoLTE test to access a variety of new HD voice and video terminal.Tests show the design and implementation of the new protocol stack of Megaco fully considers the convenience and flexibility. Using Lex and Yacc automatically generated parse code, when required to support a new set of device characteristics, thestack can quickly and easily be extended to support the new standard, which not only saves the code writing workload and reduces the chance of error code, and also reduces testing, analysis, debugging and correction time. It is conducive to the rapid iteration of the entire product.