My submission consists of a major refactor of the libtgvoip library.
The main problem of the libtgvoip library was the lack of a retransmission protocol for audio packets, so I implemented an efficient NACK mechanism with ack masks+the jitter buffer.
I added an additional transport ID, to allow multiplexing of different abstract streams (a bit like RTP), and direct mapping of seqnos => timestamps.
In the final version the transport multiplexing + new ACK feature is disabled, instead relying on sender-side packet duplication in case of packet loss using the reliable packet feature.
I've completely refactored the main controller; with multiple refactoring passes I've also optimized many places of the network loop, MessageThread, buffers and main network threads with modern C++ data structures, STL functions, smart ptrs and general logical optimizations, removing most C-isms.
(I realized I accidentally added my previous entry to the zip, sorry about that)