During the course of the project I worked on many aspects of the solution, from designing and architecting Windows Services to developing UI plug-ins for the main Windows forms application.
Working in a team of two, we architected and developed a messaging service capable of recieving, processing and routing to connected clients hundreds of thousands of messages in a reliable and performant manor. The service used remoting to communicate with connected clients and used SQL Server and the file-system to ensure the messages where never lost.
Comparison engine service
Due to the nature of the data for route optimisation, we have a goal of only writing to the switches the bare minimum - this was because routing data can be extremely large, and the connections to the switches was a slow telnet connection - this meant we needed to take a snap-shot of what was currently on the switch, and compare that to what was going to be written. The resulting change-set was then passed onto another service that would transmit the changes to the switch using MML - Man Machine Language.
Each of these services also had accomanying UI modules that where used for interact, these modules were developed using Windows Forms and our own internal UI framework.