Total number of failed Tx Transactions. So if the Mac sent a single packet, it will be retried 4 times without ACK, that counts as 1 failure.
Total number of Mac Retries regardless of whether the transaction resulted in success or failure.
Total number of Mac Tx Transactions to attempt to send a message (but not counting retries)
Time period over which MACTxyyy results are measured (in minutes)
The five most significant bits (b27,..., b31) represent the binary encoded Channel Page. The 27 least significant bits (b0, b1,... b26) indicate which channels is in use (1 = in use, 0 = not in use) for each of the 27 valid channels.