My guess is that because we are talking UDP with the associated risk of packet loss there need to me a sliding window based feedback between Dev & AIR. This would be very similar to the method used for X-25 windows over lossy media & would need a counter which would be sent in both directions.
As an aside I'm currently investigating the port 45454 protocol which is a continuous stream of UDP packets use to represent the state (volume, source selected, eq etc) used by control points (& probably also the slave Dev in a mono system). I've some Python code which I'll put in GitHub as soon as I've finally cracked it.
PS: That use "Da" as it's magic number.
Rik
As an aside I'm currently investigating the port 45454 protocol which is a continuous stream of UDP packets use to represent the state (volume, source selected, eq etc) used by control points (& probably also the slave Dev in a mono system). I've some Python code which I'll put in GitHub as soon as I've finally cracked it.
PS: That use "Da" as it's magic number.
Rik
Devialet Ensemble
Hampshire, UK