Implementing parser tool to visualize trace and error log files in Media Gateway
Marjo Jaakola · Theseus (Ammattikorkeakoulujen) · 2010
The Media Gateway (MGw) is a part of the layered network architecture. It is located in the user plane and is an interpreter taking care that transmitted data or speech is in a format an end-user device can understand. A trouble report (TR) includes one or more text files describing what has happened in a call in the MGw. Thus it takes a long time to figure out a setup of a call and what has actually happened in the call before one can even start to look at the actual problem. Obviously, there was a need for an improvement, which led to the research question: "How to visualize textual information describing a call?" Since nothing like this has been done earlier the thesis is divided into two parts. In the first part the different ways of implementing a parser tool were researched and in the second part the parser tool was implemented and tested. The main emphasis of the thesis is in the actual implementation and the analysis of the results. The first part of the thesis introduces the parser theory and sets the requirements for the parser tool. Moreover, a desk research with different parser generators was performed. Based on the result of the desk research the Pyparsing was chosen for developing the parser tool. The second part of the thesis describes the implementation and the results, and provides an answer to the research question. It was found that the parser tool is able to visualize the textual information in several ways; identifying a termination for a request, extracting a service information from a bitmap, showing whole context at all times, providing a stream mode and connection status in the graphical format. Moreover, it was found that the visualization made it is easier and much faster to get an overall picture of what was going on in a call. In addition, it made it easier to spot problems, e. g. seeing that there was no through connection or ensuring that the correct services were reserved. The parser tool is currently used by several persons and there is a plan to integrate it to the test commander tool, which will include the output file from the parser tool automatically to the trouble reports in the future.