change session-timeout

[sub]

Hello everybody,
I looked around a bit but without success.

I currently use freeradius for several services and I have the
following scenario:
- a user is authenticated through a NAS;
- due to some event my application/script or something recalculate the
Session-Timeout value, normally decreasing it of X seconds.

Can I send the updated value of the Session-Timeout attribute to the NAS?

Thanks,
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sub