I’m trying to optimize / reduce data usage as much as possible. In this case, somewhat frequent updates, seconds or minutes, with no requirement for guaranteed delivery or confirmation if a message is dropped. I’ve been thinking UDP as with a TCP connection I’d potentially need a keepalive to avoid the overhead of a repeat TCP & TLS handshake, that is unless I send frequently enough to prevent the connection from closing. In my tests, utilizing “+USOST” to transmit differing sized UDP packets I noticed something unexpected.
UDP payload size → Hologram dashboard usage
3 bytes → 90 bytes
16 → 116
64 → 212
The reason I found this odd is the difference in sizes. 16 - 3 = 13 is not equal to 116 - 90 = 26, though they are evenly divisible, by two. The usage on the dashboard always seems to be 84 + (data length * 2) or perhaps more correctly (42 + data length) * 2 ? I realize there will be some amount of overhead, as a UDP header is 8 bytes, and an IP header is 20 bytes. Not quite 42 bytes, so I wonder what the framing structure / headers look like, and even more so curious why the doubling.