Limitations#

• This feature only applies to the NVM3 stack token group.

• The UART-based EZSP token data transfer relies on the EZSP transport mechanism. It does not have any data integrity as part of the host reading out the tokens and saving them to the file.

• The file format is evolving. The current custom format is as documented.

• The security and integrity of the file that stores the token data is not implemented.

• The backup subroutine on the host runs a continuous loop to collect the token data. This implies the following:

  • Backup cannot be a continuous process over time, as some of the tokens may get rewritten based on network activity between the start and end of the backup.

  • The one-time backup process is recommended for a time when no other network activity such as joining is happening, ideally just before the gateway is taken down for replacement. In this way the backup contains the latest operational token set before replacement.

  • Host application developers may choose to back up those tokens that do not change over a period of time to avoid the continuous loop and thereby to improve host performance. Use the above host subroutines as a starting point reference.

• A reset on the NCP is required after the restore because most of the operational RAM tables only get initialized from the token in the power-on reset path.

• This feature does not back up or restore any ephemeral RAM data such as neighbor table or incoming frame counters, as these are built back upon incoming packets after the network is restored.