This is a continuation of the previous post .
During this month I have implemented the NetJSON plugin for BIRD. It exposes the topology of an OSPF Area using the network-graph format and thus allows Prince to fetch the topology and calculate the timer’s value.
I deployed a small testbed to debug my code using the network emulator called CORE 
Here you can see the testbed:
I’m currently working on this repository  and I’m looking forward to send a PR to BIRD.
I defined a new command in the bird’s cli: “show ospf topology netjson”. It returns a network-graph output that can be used by prince or by any other NetJSON compatible software.
Here you can see the topology of the testbed using d3.js .
In this next coding period I will implement a plugin for Prince that interacts with BIRD. Unfortunately it uses a UNIX Domain socket instead of a network socket, so I’ll need to code the communication routines from scratch.