Editing SimTX API/Limits and errors (section)

== Diagnosing a refused session ==
When a start is refused or a connection closes, check in this order:
# '''The code and reason.''' A SessionStatus or Error says what was wrong. Log both.
# '''Framing.''' A wrong length prefix or a missing preface makes every later byte look like garbage. Test the codec against the examples on the packet pages first.
# '''Encoding.''' Protobuf scalars are little-endian; IQ sample bytes are big-endian. Strings are UTF-8 with a varint length. UUIDs are 16 raw bytes, not text.
# '''Values.''' Latitude in −90 to 90, longitude in −180 to 180, finite floats, non-negative noise figure and frequency, positive bandwidth and sample rate, a callsign of 1 to 64 printable characters, exactly one site member.
# '''Frame order.''' A receiver may send only ReceiverRetune, AntennaPointingUpdate and Ping after its start. A control session accepts only control requests.
# '''Tickets and bindings.''' A ticket is single-use and valid for 60 seconds, for one server and one role; a station-bound start must match the station, antenna and rig of its ticket.
# '''Limits.''' Too many receivers from one address, a wideband request over budget, a full station, or control requests too fast.