It has EXPLICITLY stated in the specs:
It MAY be used by the client to mark the start of accounting (for example, upon booting) by specifying Accounting-On and to mark the end of accounting (for example, just before a scheduled reboot) by specifying Accounting-Off.
The RADIUS CLIENT is rebooting. Not a sub-system. Not a card. Not a process re-starting. The RADIUS CLIENT.
That -isn't- explicitly stated, it is saying that they should be sent to mark the start or end of accounting - that's not tied to only a startup, a reboot or a shutdown. The spec uses those as examples of when it is appropriate. It doesn't say they are the only times that they can be sent. The spec does not prohibit WLAN vendors scoping the start or end of accounting with a Calling-Station-Id so some seem to have taken that liberty, and send these on a per-BSS basis and not on a per-NAS basis. I agree with you that adding a new Acct-Status-Type would be more appropriate and mandating that Accounting-On and Accounting-Off be sent only on a per-NAS basis would be the best way forward. Yes, we could do with a new spec that cleans this up! :) Nick