The Internet protocols often form the basis for data communication education and are also under active research. Useful tools for studying the behavior of real protocol implementations, in particular for educational purposes, are always highly appreciated.
The idea is to gather packet trace information from real data communication traffic and take the traces as input for playback animation to study the protocol message exchange. The main form of animation could be the chronological drawing of protocol messages using a typical message sequence chart format. Other types of animation can be considered as well.
The packet traces for the Internet protocols can be gathered using tcpdump or similar tool. The tcpdump output log contains all necessary packet information required for animation, but other logs could be used to include additional information, for example, a log created in an end host that contains a serie of values for the certain protocol variables at the time of specific protocol events. In order to enable the correct presentation of the protocol events - in particular the correct ordering of events (e.g., arrival/departure of messages) at both protocol end systems, the packet traces should be gathered at each end and consolidated to create a complete view of the events (e.g., packet losses, reordering) for animation. The focus is on protocol operations involving two communicating end points, but the same idea could be extended to cover communication scenarios in which more than two protocol entities are involved.
In the animation the basic protocol information (e.g., message type and sequence number) should always be present, but more detailed information could be shown per user request.
It is suggested to begin with the Internet transport protocols (TCP, UDP), but to take into account in the design the possibility for later extensions that enable showing lower and higher protocol layer information as well.
The following educational goals are aimed with the SE project:
- Students: The students should have an impression of both a typical software engineering project and of a distributed project.
- Scientists: The members of the joint project wish to gather information about these types of projects, results, problems, advantages, and disadvantages. The experiences of the projects are gathered together so that the structure and guidelines of this types of projects may be revised.
Experimental distributed project:
* The project is divided into two groups: one in Helsinki and one in Petrozavodsk. Both groups have their own instructor. The customer of the project communicates with both groups.
* The groups communicate with each other via email, chat programs, and video conferences. They maintain a common web page and maintain version control in CVS. The communication language of the project is English.
* The design, implementation, unit and integration testing phases of the software are mostly local to both groups while the requirements engineering phase and the final testing phases are joint ones.
