Their blog post suggests they wrote something from scratch, but gives no clue as to what, whether they considered building on a more modern protocol specificati

Their blog post suggests they wrote something from scratch, but gives no clue as to what, whether they considered building on a more modern protocol specification than RTP (which is a couple decades old at this point), what they've taken from other more modern protocol specs if they didn't use one directly, or anything aside from that they wrote some code really.