IPA part of the fields in the message are specifically used to describe the life cycle of the message, namelyTTLValue, what is its maximum value?

Regarding the UA5000 IPMB single board, which one of the following descriptions is wrong?

Is the following description correct? When upgrading the version, use the database upgrade tool to upgrade the dat file to the higher version, and you can also use the upgrade tool to reduce the dat file of the higher version to the lower version.

Is the following description correct? Users can establish PVC connections between different board ports or between different ports on the same board. The main purpose is to realize the point-to-point interconnection between two different users.

command... What is the correct description of the three points in ./.profile?