private bool IsGreeting(byte[] buffer, int offset, int max_offset)
{
byte[] greeting = { PTP.PTP_GREETING_PREAMBLE1, PTP.PTP_GREETING_PREAMBLE2, 0x43, 0x6E, 0x65, 0x74, 0x0D }; //BACnet\n
max_offset = Math.Min(offset + greeting.Length, max_offset);
for (int i = offset; i < max_offset; i++)
if (buffer[i] != greeting[i - offset])
return false;
return true;
}