RADIUS attribute 40 · type integer
Acct-Status-Type
Acct-Status-Type (attribute 40) says what an accounting record is: Start (1) when a session begins, Stop (2) when it ends, Interim-Update (3) for periodic usage snapshots.
Also searched as: Accounting Start Stop, Acct-Status-Type Interim-Update. Defined in RFC 2866.
What it means
Every RADIUS Accounting-Request declares its purpose through Acct-Status-Type. Start opens a session, Stop closes it (carrying the session's totals and a termination cause), and Interim-Update reports usage mid-session. Accounting-On (7) and Accounting-Off (8) signal a NAS reboot, telling the server to close any sessions it thought were still open on that device.
How it's used
Read it to drive session state in your accounting store. A missing Stop (NAS lost power, packet dropped) leaves a session open forever — Accounting-On from the rebooted NAS is the signal to clean those up.
Values
1— Start — a session has begun.2— Stop — a session has ended (includes final counters).3— Interim-Update — periodic mid-session usage report.7— Accounting-On — the NAS has (re)started; close its stale sessions.8— Accounting-Off — the NAS is shutting down.
Common gotchas
- Lost Stop packets are normal at scale; rely on Interim-Update and Accounting-On to reconcile, not on Stop always arriving.