Hello VoIP guys

Sorry for being somewhat off-topic. At the moment I am studying informatics in the seventh semester and I need to start thinking about my thesis. As I am very interested in VoIP technologies I thought about picking this as my main topic. So far I have only little experience in this area. I have been fiddling around with siproxd and pfSense and have red the one or the other packet dump containing SIP and RTP traffic, had a look into codecs, STUN, etc... but very cursorily, and that's the reason why I am quite unsure on which track to go. I think I am quite familiar with many network protocols and devices... so here comes the question of the questions:

What would be a great project for my thesis to work on in the VoIP field? What are topics that still need special development? The time frame should be around 300 hours but don't take this value too seriously...

Any ideas are welcome!

/sp4rc